This post presents the annual cycle in sea surface temperatures for the hurricane main development region in the North Atlantic.  It also presents the sea surface temperature anomalies for three regions: (1) the Main Development Region, (2) the Gulf of Mexico and (3) the Coastal Waters north of the tropics along the East Coast of the United States, which is the extratropical portion of Hurricane Sandy’s path.  Those three subsets are presented in weekly and monthly formats using the satellite-based Reynolds OI.v2 sea surface temperature dataset, and I’ve also shown them based on NOAA’s ERSST.v3b long-term sea surface temperature reconstruction.   And since tropical storm development is inhibited by El Niño events, I’ve also presented the weekly NINO3.4 sea surface temperature anomalies.  As an afterthought, I’ve added the weekly data for the Caribbean.

INTRODUCTION

The 2013 hurricane season is fast approaching.  Last month, Klotzbach and Gray of Colorado State University published their Extended Range Forecast of Atlantic Seasonal Hurricane Activity and Landfall Strike Probability for 2013. The opening page reads:

We anticipate that the 2013 Atlantic basin hurricane season will have enhanced activity compared with the 1981-2010 climatology. The tropical Atlantic has anomalously warmed over the past several months, and it appears that the chances of an El Niño event this summer and fall are unlikely. We anticipate an above-average probability for major hurricanes making landfall along the United States coastline and in the Caribbean. Coastal residents are reminded that it only takes one hurricane making landfall to make it an active season for them, and they need to prepare the same for every season, regardless of how much or how little activity is predicted.

Figure 1 – Annual Cycle in Main Development Region Sea Surface Temperatures

Sea surface temperatures are an important component of hurricane development.  Tropical storms need a lot of warm water to grow.  The following is a paragraph from Chapter 4.18 [ENSO Influence on Tropical Cyclones (Hurricanes)] from my book Who Turned on the Heat?

The recipe for a tropical cyclone has three primary ingredients. The first is warm water—waters in excess of 26 deg C. Because the tropical storm feeds off the warm water, it cools the sea surface, so the warm water has to reach depths of about 60 meters in order to support the development of the tropical cyclone. The second ingredient is moisture and lots of it. The moisture has to cover a large area and be thick, normally extending from the sea surface to altitudes to 20,000 feet (about 465mb). The third ingredient is relatively light winds. That’s where an El Niño spoils the recipe.

An El Niño event in the tropical Pacific causes stronger-than-normal high level westerly winds in the Main Development Region of the tropical North Atlantic, and those strong high level winds can cause wind shear.

Figure 1 shows the annual cycle in sea surface temperatures for the Main Development Region in the North Atlantic, which is bordered by the coordinates of 10N-20N, 80W-20W. It’s easy to see why the official Atlantic hurricane season lasts from June through November. Sea surface temperatures in the Main Development Region are coolest in February and March and warmest in September and October.

So where do we sit this year? And what about the Gulf of Mexico? And the waters off the east coast of the U.S. where Sandy tracked last year before making the left turn into New Jersey?

WEEKLY SEA SURFACE TEMPERATURE ANOMALIES

Weekly sea surface temperature and temperature anomaly data (deviations from the average monthly values of the period of 1971-2000) based on the Reynolds OI.v2 dataset are available from NOAA NOMADS website—as are the short-term (November 1981 to present) monthly data that follow.  The Reynolds OI.v2 dataset is based on satellite data and from ship inlets and buoys (fixed and floating).  The weekly data is centered on Wednesdays and begins in January 1990.

Figure 2 shows the weekly sea surface temperature anomalies for the main development region through Wednesday May 8, 2013. I’ve also highlighted the current value in red as the horizontal line. Klotzbach and Gray were obviously correct with, “The tropical Atlantic has anomalously warmed over the past several months…”

Figure 2

Those living along the Gulf Coast are always concerned about the sea surface temperature anomalies in the Gulf of Mexico. At present, sea surface temperature anomalies there are below the 1971-2000 average by a significant amount. See Figure 3.  That’s not to say that the Gulf won’t spawn any hurricanes this year.  This is simply an indication that sea surface temperatures in the Gulf, as a whole, are cooler than normal now.

Figure 3

And those living along the Eastern Seaboard are concerned about the sea surface temperatures along the East Coast.  I’ve used the same coordinates in Figure 4 that I used for the discussions of sea surface temperatures along the extratropical portion of Sandy’s storm track in two posts last year.  See here and here. At present, sea surface temperature anomalies are below the average of the base period of 1971 to 2000.

Figure 4

And, yes, that severe drop toward the end of 2012 occurred the week of Sandy. While sea surface temperatures were not exceptionally warm last year along the extratropical storm track, Sandy did pull a lot of heat from that portion of the Atlantic. I’ll let you decide if that will impact the storms this year.

SATELLITE-ERA MONTHLY DATA

For those interested in a longer-term look at the data, Figures 5, 6 and 7 present the monthly sea surface temperature anomalies for those regions, again using the Reynolds OI.v2 dataset. The monthly data starts in November 1981 and runs through April 2012. I’ve also included the most recent values as red horizontal lines for easier comparisons.

Figure 5

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Figure 6

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Figure 7

MONTHLY LONG-TERM RECONSTRUCTION

And for those wanting a further look back in time, Figures 8 through 10 show the April 2012 sea surface temperatures highlighted in red for the 3 regions, using NOAA’s ERSST.v3b dataset, which starts in January 1854. The ERSST.v3b data is available through the KNMI Climate Explorer. Due to the number of corrections before 1950 and the severity of them, the early data has to be looked on with a pinch of salt, especially when looking at relatively small regions as we are with Figures 9 and 10.

Figure 8

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Figure 9

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Figure 10

What I did find surprising, Figure 11, was that the main development region data remained relatively flat from 1930 to 1995.  That is, according to the ERSST.v3b data, there was little warming there for 6 ½ decades. In Figure 11, the red line is the linear trend as determined by EXCEL.

Figure 11

EL NIÑO-SOUTHERN OSCILLATION

As noted earlier, El Niño events in the tropical Pacific cause increased wind shear in the North Atlantic and that suppresses hurricane development there.  The ENSO forecasting models are not predicting an El Niño event this season, see pages 25 through 27 of NOAA’s weekly ENSO update, so Klotzbach and Gray considered the absence of El Niño conditions when making their hurricane season predictions.

Figure 12 presents a graph of the weekly sea surface temperature anomalies for the NINO3.4 region in the east-central equatorial Pacific.  NINO3.4 sea surface temperature anomalies are a commonly used index of the strength, frequency and duration of El Niño and La Niña events. According to NOAA, El Niño conditions exist when the sea surface temperature anomalies are warmer than +0.5 deg C. As of last week, the NINO3.4 data was showing an anomaly of effectively zero.

Figure 12

OOPS FORGOT TO ISOLATE THE CARIBBEAN

The Main Development Region is quite large, extending from the Caribbean Sea to almost the coast of Africa, and sea surface temperatures can differ quite a bit from west to east. Figure 13 shows the weekly sea surface temperature anomalies for the Caribbean Sea, using the coordinates of 10N-20N, 84W-60W.  Sea surface temperatures there are also above normal, but not as high as they are toward the eastern portion of the main development region.

Figure 13

CLOSING 

For four years, I’ve been illustrating and discussing how ocean heat content and satellite-era sea surface temperature data indicate the oceans warmed naturally. That doesn’t stop climate change alarmists from making all sorts of nonsensical claims.  If the natural warming of the oceans is new to you, refer to the illustrated essay “The Manmade Global Warming Challenge” [42MB].

Figure 14 is a sea surface temperature anomaly map of the North Atlantic, for the week centered on May 8, 2013. Just because sea surface temperature anomalies are below normal along the Gulf and southeast coasts right now, that doesn’t mean they’re going to remain there for the 2013 hurricane season.  Also, hurricanes don’t care about anomalies. Sea surface temperatures can be below normal, but if they’re warm enough (in absolute terms), they’ll support a hurricane.

Figure 14

As Roger Pielke, Jr. reminded us last December in his post Record US Intense Hurricane Drought Continues:

When the Atlantic hurricane season starts next June 1, it will have been 2,777 days since the last time an intense (that is a Category 3, 4 or 5) hurricane made landfall along the US coast (Wilma in 2005). Such a prolonged period without an intense hurricane landfall has not been observed since 1900.

While this fact counters many claims by global warming enthusiasts, it also indicates we’re long overdue for one.

INTRODUCTION

A new paper about fish migration patterns from 1970 to 2006 is getting some attention by the press. My Figure 1 is Figure 2 from Cheung et al (2013). Click it to enlarge it.

Figure 1

As usual, global warming enthusiasts in the press overlook some basic issues—like the sea surface temperatures for the Indian and Pacific Oceans from pole to pole haven’t warmed in 19+ years, and the Atlantic data show little warming for more than a decade. Further, the tropical Indian and Pacific sea surface temperatures haven’t warmed since 1986. It’s therefore difficult to make claims like “more evidence of a rapidly warming planet”, but that doesn’t stop proponents of hypothetical human-induced global warming.

BACKGROUND

Anthony Watts presented the press release for the paper Cheung et al (2013) Signature of ocean warming in global fisheries catch in the WattsUpWithThat post Fishy Temperature Proxy. And ClimateDepot’s Marc Morano alerted me earlier in the day to Lenny Bernstein’s May 15th article in the Washington Post. See “Worlds fish have been moving to cooler waters for decades, study finds”. The first two paragraphs of Bernstein’s article read (my boldface):

Fish and other sea life have been moving toward Earth’s poles in search of cooler waters, part of a worldwide, decades-long migration documented for the first time by a study released Wednesday.

The research, published in the journal Nature, provides more evidence of a rapidly warming planet and has broad repercussions for fish harvests around the globe.

Rapidly warming planet? Maybe the author of the Washington Post article should check sea surface temperature data before making nonsensical comments.

The University of British Columbia press release for the Cheung et al (2013) paper is titled “Fish thermometer” reveals long-standing, global impact of climate change. The opening two paragraphs of the press release provide a good overview of the paper:

Climate change has been impacting global fisheries for the past four decades by driving species towards cooler, deeper waters, according to University of British Columbia scientists.

In a Nature study published this week, UBC researchers used temperature preferences of fish and other marine species as a sort of “thermometer” to assess effects of climate change on the worlds oceans between 1970 and 2006.

I found no explanation in the paper about why they ended the study period in 2006 for a paper published in 2013 or, phrased another way, why they overlooked the most recent 6 years of sea surface temperature data. That aside…

WHAT THE PRESS RELEASE AND THE WASHINGTON POST AREN’T BOTHERING TO TELL THE PUBLIC

As noted in the introduction, the sea surface temperature anomalies of the Indian and Pacific Oceans from pole to pole (90S-90N, 20E-70W) haven’t warmed in 19 years. See Figure 2. The sea surface temperature anomalies for this major portion of the global oceans obviously warmed during the study period, 1970 to 2006, but they show no warming if the data is extended to current times and if we start the trend analysis in January 1994. In other words, the sea surface temperature data for about 70% of the surface of the global oceans provide no indication of warming for almost 2 decades.

Figure 2

That leaves us with the Atlantic data. It also shows warming from 1970 through 2006, but if we examine the data from January 2002 to January 2013, the trend has been remarkably flat—which suggests a possible slowdown in the warming rate of the sea surface temperatures in the Atlantic, too. It’s a little early to tell there, though, because there have been similar decadal slowdowns in the rate of warming in the Atlantic since 1970. It’s only a matter of time there, though. Eventually, the Atlantic Multidecadal Oscillation will cause the sea surface temperatures in the North Atlantic to peak, flatten and then start to cool—as it has for hundreds if not thousands of years. See NOAA’s FAQ webpage about the AMO.

Figure 3

The press release provides a link to a Pew Charitable Trusts – Environmental Initiatives overview of Cheung et al (2013). There they state (my boldface):

The authors found that, except in the tropics, catch composition in most ecosystems slowly changed to include more warm-water species and fewer cool-water species. In the tropics, the catch followed a similar pattern from 1970 to 1980 and then stabilized, likely because there are no species with high enough temperature preferences to replace those that declined. Statistical models showed that the increase in warm-water species was significantly related to increasing ocean temperatures.

What they forgot to tell you was that the sea surface temperatures of the tropical Indian and Pacific Oceans (24S-24N, 35E-80W) warmed drastically in response to the 1976 Pacific Climate Shift, see Figure 4, and then have remained relatively flat since then. In fact, the sea surface temperatures of the tropical Indian and Pacific Oceans show no warming since 1986, or for more than 2 ½ decades.

Figure 4

So where’s the “rapidly warming planet”?

CHEUNG ET AL (2013) DIDN’T SPECIFICALLY IDENTIFY THE HADISST SEA SURFACE TEMPERATURE DATA

Usually, peer-reviewed papers identify what datasets were used in the study. This courtesy appears to have been overlooked in Cheung et al (2013). Figure 2 in Cheung et al (2013) suggests a sea surface temperature dataset that has been infilled, because the trend analysis maps in their Figure 2 show data in the high latitudes of the Southern Hemisphere. And they also refer to the Hadley Centre’s sea surface temperature climatology in the paper. But for sea surface temperatures, Cheung et al (2013) don’t cite the expected Rayner et al (2003) for HADISST. They cite Belkin (2009) Rapid warming of large marine ecosystems, which cites Rayner et al (2003).

CLOSING

The Cheung et al (2013) paper hasn’t yet received the normal end-of-the-world-as-we-know-it hype from the alarmist blogs Climate Progress and SkepticalScience. It’s still a little early, though. Give Climate Progress and SkepticalScience a little while before they join the Washington Post, where Lenny Bernstein elected to make the claim of a “rapidly warming planet”. As so often happens, claims about warming sea surface temperatures are not supported by sea surface temperature data.

And of course, ocean heat content and satellite-era sea surface temperature data indicate the oceans warmed naturally. If this topic is new to you, refer to the illustrated essay “The Manmade Global Warming Challenge” [42MB].

HHHHHHHH

This post presents a number of problems the 2005 Hartmann and Wendler paper “The Significance of the 1976 Pacific Climate Shift in the Climatology of Alaska.” These include the misuse of the Pacific Decadal Oscillation (PDO) index and the erroneous conclusions derived from that misuse.

On page 14 of the 16-page paper, Hartmann and Wendler (2005) note:

This current debate presents the fact that more work is needed to further define North Pacific climate indices and implications.

Much of the obvious confusion could be eliminated if researchers stopped using abstract forms of sea surface temperature data like the PDO and began to use actual sea surface temperature anomalies. In other words, they should use the right tool for the job.

MISUSE OF THE PACIFIC DECADAL OSCILLATION INDEX

The abstract of Hartmann and Wendler (2005) begins:

The 1976 Pacific climate shift is examined, and its manifestations and significance in Alaskan climatology during the last half-century are demonstrated. The Pacific Decadal Oscillation index shifted in 1976 from dominantly negative values for the 25-yr time period 1951–75 to dominantly positive values for the period 1977–2001.

And the abstract concludes with following two sentences:

When analyzing the total time period from 1951 to 2001, warming is observed; however, the 25-yr period trend analyses before 1976 (1951–75) and thereafter (1977–2001) both display cooling, with a few exceptions. In this paper, emphasis is placed on the importance of taking into account the sudden changes that result from abrupt climatic shifts, persistent regimes, and the possibility of cyclic oscillations, such as the PDO, in the analysis of long-term climate change in Alaska.

The authors should be commended for considering the impacts of natural variability on Alaskan climate. However, they fail to recognize that the Pacific Decadal Oscillation (PDO) does not represent the sea surface temperature anomalies of the North Pacific north of 20N (the area on which the PDO data is based), or the Pacific Ocean as a whole, or the coastal waters of Alaska. This is clearly visible in Figure 1, which compares the Pacific Decadal Oscillation Index data (red) to the sea surface temperature anomalies of the North Pacific north of 20N (brown), the Pacific Ocean as a whole (light blue) and of the coastal waters of Alaska (dark blue).

Figure 1

The decadal variability of the PDO does not agree with the variations in the other three datasets. This can be shown by detrending and standardizing the sea surface temperature anomalies of the North Pacific north of 20N, the Pacific Ocean and of the coastal waters of Alaska and smoothing them (and the PDO index) with 121-month running-average filters. See Figure 2.

Figure 2

The Pacific Decadal Oscillation index is a statistically created dataset that does not represent the sea surface temperatures of the region of the North Pacific from which it is derived, nor does it represent the sea surface temperature anomalies of the Alaskan coastal waters, which should have a direct impact on the land surface air temperatures of Alaska. It therefore appears as though the authors used the wrong dataset as their reference for the sea surface temperatures.

CLIMATE SHIFTS

There’s another way to illustrate the confusion caused by the use of the PDO index as a reference for North Pacific sea surface temperature anomalies, and that is in the context of climate shifts.

The primary focus of the paper was the impact of the 1976 Pacific Climate Shift on Alaskan climate—hence the title of the paper. The authors used temperature data starting in 1951 so we’ll use the same start year, and we’ll end the sea surface temperature data at present times.

Contrary to assumptions made using the PDO index, the sea surface temperature anomalies of the North Pacific north of 20N (which is the area from which the PDO index is derived) do not include a climate shift in 1976. The climate shift for the extratropical North Pacific occurred in 1988-89. See Figure 3. That’s about the same time as the climate shift in North Pacific ocean heat content.

Figure 3

On the other hand, the sea surface temperature anomalies of the Alaskan coastal waters did experience a climate shift in 1976, Figure 4. Sea surface temperature anomalies cooled from 1951 to 1975, and cooled again from 1977 to present. The two cooling trends before and after the 1976 climate shift suggest that the 1976 shift is responsible for the long-term trend of 0.055 deg C per decade for the Alaskan coastal waters.

Figure 4

Hartmann and Wendler (2005) could have used the actual sea surface temperature anomalies for the Alaskan Coastal Waters in their paper. It would have kept to their overall objective of citing the 1976 Pacific Climate Shift as a cause for the long-term warming and would have avoided the confusion associated with the use of the PDO index, which is an abstract form of sea surface temperature data.

MORE ON THE 1976 PACIFIC CLIMATE SHIFT

To help clarify a few things, let’s borrow the next two illustrations from an earlier post, Blog Memo to John Hockenberry Regarding PBS Report “Climate of Doubt”. As noted in Figure 3, the 1976 climate shift is not a North Pacific phenomenon. It’s a shift in East Pacific sea surface temperature anomalies, Figure 5. It effectively shifted the sea surface temperatures of the East Pacific (90S-90N, 180-80W) up 0.17 deg C. In other words, that’s a natural rise in sea surface temperatures of almost 0.2 deg C for 33% of the surface area of the global oceans.

Figure 5

The Great Pacific Climate Shift also refers to the change in the basic state of the ocean processes taking place in the tropical Pacific. See Figure 6. After 1976, El Niño events dominated, but for the period from the early-1940s to 1976, El Niños and La Niñas were more evenly matched, with La Niñas just a little bit stronger.

Figure 6

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OVERVIEW

This is a somewhat lengthy blog post. There’s lots of information for newcomers, and there are new presentations of data (new for me) for those who have already examined multidecadal variations in sea surface temperatures.

This post presents the multidecadal variations in sea surface temperatures in the North Atlantic, the North Pacific and in the Southern Hemisphere. It presents those multidecadal variations using the three primary sea surface temperature reconstructions—NOAA’s ERSST.v3b, and the UKMO Hadley Centre’s HADISST and HADSST3 datasets—to highlight the subtle differences in the timings and magnitudes of those variations. Last, this post reminds the reader that the long-term sea surface temperature dataset are reconstructions and that they differ quite drastically from the source data.

Figure 1

This post does not comment on peer-reviewed journal articles. It presents data, and it will hopefully give you a better background in long-term sea surface temperature data. That way you can have a deeper understanding of the topic when you read a paper or blog post about multidecadal variability.

INTRODUCTION

The multidecadal variability of sea surface temperatures is a reoccurring topic in temperature data analyses, climate model-based studies, and, of course, in posts around the climate change blogs.

The pause or hiatus in global warming has resurrected it. Multidecadal variations in sea surface temperatures were discussed in David Appell’s post W[h]ither Global Warming? Has It Slowed Down? He writes:

These increases are certainly less than the warming rates of the 1980s and first half of the 1990s of about 0.15 to 0.20 C (.27 and .36 F respectively) and per decade. The earlier period may have provided an unrealistic view of the global warming signal, says Kevin Trenberth, climate scientist with the National Center for Atmospheric Research in Boulder, Co.

“One of the things emerging from several lines is that the IPCC has not paid enough attention to natural variability, on several time scales,” he says, especially El Niños and La Niñas, the Pacific Ocean phenomena that are not yet captured by climate models, and the longer term Pacific Decadal Oscillation (PDO) and Atlantic Multidecadal Oscillation (AMO) which have cycle lengths of about 60 years.

Note: To head off those who want to claim the heat is being stored deeper in the oceans, we’ve addressed that in numerous posts over the past few months. Working back in time, refer to the posts here, here, here, here and here for example.

SkepitcalScience had a recent post about Tung and Zhou (2013) “Using data to attribute episodes of warming and cooling in instrumental records”. The final sentence in the abstract of Tung and Zhou reads:

Quantitatively, the recurrent multidecadal internal variability, often underestimated in attribution studies, accounts for 40% of the observed recent 50-y warming trend.

The author of the SkepticalScience post disagreed with that paper, and titled his flawed critique Tung and Zhou circularly blame ~40% of global warming on regional warming. That SkepticalScience post was written by a blogger who calls himself “Dumb Scientist”. (Note to “Dumb Scientist”: If you want your posts to be taken seriously, you need to change your name.) SkepticalScience, to its credit, has posted a 2-part reply by KK Tung, the lead author of that Tung and Zhou (2013) paper. I haven’t read the first part of KK Tung’s rebuttal, but I’ve read the second part, and it is worth reading. You’ll note that one of Tamino’s graphs appears in it, as Figure 5.

Speaking of Tamino, he presented a post about the Atlantic Multidecadal Oscillation, see his post here, and I replied to it in my post Comments on Tamino’s AMO Post. In another of his posts, Tamino took exception to a comment I made that climate models cannot reproduce the multidecadal variations exhibited in the temperature record, and in my response, I presented the outputs of all of the CMIP3 climate model simulations in a gif animation to show that the vast majority of the model simulations do not present the multidecadal variability that exists in the data.

Some model-based studies say multidecadal variations are caused by changes in anthropogenic and natural aerosols, while data and other climate models point to internal natural variability. No consensus there. Refer to Isaac Held’s blog post Atlantic multi-decadal variability and aerosols.

Many times it seems researchers and bloggers lose track of the fact that the data they’re examining has been reconstructed and that it differs greatly from the source data—and that it differs greatly from one reconstruction to another. There are also instances when researchers appear to forget how sparse the source sea surface temperature data is and that they’re examining data that has been infilled using statistical tools—and that they’re primarily performing statistical analyses not of data, but of the statistically created infillings. In other words, they’re studying make-believe data.

There are also numerous ways to present the multidecadal variations in sea surface temperatures. The Atlantic Multidecadal Oscillation is sometimes presented in very abstract forms, but it is most often portrayed as sea surface temperature anomalies of the North Atlantic that have been detrended. See the NOAA ESRL webpage about their AMO (Atlantic Multidecadal Oscillation) index. They note:

Method:

1. Use the Kaplan SST dataset (5X%)

2. Compute the area weighted average over the N Atlantic, basically 0 to 70N.

3. Detrend that time series

4. Optionally smooth it with a 121 month smoother

That is, with detrending, the sea surface temperature anomaly curve of the North Atlantic is basically laid on its side to help highlight the multidecadal changes in sea surface temperatures there. Detrended North Atlantic (0-70N, 80W-0) sea surface temperature anomalies are shown in Figure 1.

Note: I have not presented the NOAA ESRL version of the AMO index data in this post. That data are based on the Kaplan sea surface temperature reconstruction. Unfortunately, the Kaplan data was removed from the KNMI Climate Explorer, which is the source of data for this post.

On the other hand, the variations in the North Pacific data north of 20N are typically presented in a very abstract form known as the Pacific Decadal Oscillation (PDO) index. (Not illustrated.) See the JISAO webpage here. The PDO index is inversely related to the sea surface temperatures of that region in the North Pacific, so the PDO index only adds confusion in discussions of global surface temperatures. The PDO index is also standardized (the data is divided by its standard deviation) and this exaggerates the magnitude of its variability, making it appear (on a graph without units) to be as strong as the variations in sea surface temperature anomalies (in deg C) along the equatorial Pacific caused by El Niño and La Niña events.

To make matters even more confusing, many times a climate scientist or blogger will use the name Pacific Decadal Oscillation when talking about the multidecadal variations in the sea surface temperatures of the North Pacific, which are not represented by the PDO index.

To minimize confusion, we’ll only use detrended data to illustrate multidecadal variability in this post. And when the data have been detrended, the title blocks note it. I’ve also provided the data in its standard form to keep things in perspective.

Also, to help show the differences between ocean basins, the long-term data have been smoothed with 61-month filters. This minimizes the year-to-year wiggles due to El Niño and La Niña events but does not smooth the data as much as the 121-month filter, which NOAA’s ESRL applies to their Atlantic Multidecadal Oscillation index data. The lesser filtering will also help to show the subtle differences between datasets when we look at comparisons of the detrended data with the three long-term reconstructions.

THE MULTIDECADAL VARIATIONS IN THE SEA SURFACE TEMPERATURES OF THE NORTH ATLANTIC ARE WELL STUDIED. BUT WHAT ABOUT THE NORTH PACIFIC?

The Atlantic Multidecadal Oscillation is well studied and there are numerous posts and websites about it. NOAA has their informative webpage Frequently Asked Questions About the Atlantic Multidecadal Oscillation (AMO). I provided an introductory post about the Atlantic Multidecadal Oscillation here. RealClimate has a very brief overview here. And Wikipedia discusses the Atlantic Multidecadal Oscillation here. The first sentence of the Wikipedia webpage reads:

The Atlantic Multidecadal Oscillation (AMO) is a mode of variability occurring in the North Atlantic Ocean and which has its principal expression in the sea surface temperature (SST) field.

NOAA’s FAQ webpage provides a similar but easier-to-read answer to the question “What is the AMO?”:

The AMO is an ongoing series of long-duration changes in the sea surface temperature of the North Atlantic Ocean, with cool and warm phases that may last for 20-40 years at a time and a difference of about 1°F between extremes. These changes are natural and have been occurring for at least the last 1,000 years.

As discussed earlier, and shown in Figure 1, the Atlantic Multidecadal Oscillation is often presented as detrended North Atlantic sea surface temperature anomalies. Refer to the illustration here for an overview of detrending. Rarely do discussions of the Atlantic Multidecadal Oscillation note that it also extends into the tropics of the South Atlantic—see the illustration here, from this post. I also have not found any peer-reviewed journal articles that explain why the sea surface temperatures of the North Atlantic do not cool proportionally during the 1988/89 and 1998-01 La Niña events; we can show this here (from this post) by detrending short-term (satellite-era) sea surface temperature anomalies of the North Atlantic and comparing them to a scaled ENSO index.

Those items aside, the multidecadal variations in the sea surface temperature data of the North Atlantic appear in many data-based and model-based studies. So is the North Pacific sea surface temperature data. Unfortunately, most studies of the North Pacific data present it in an abstract form called the Pacific Decadal Oscillation (PDO) index. The PDO represents the strength of the spatial pattern of the temperature anomalies in the North Pacific. (Example: A spatial pattern with warm anomalies to the east and cooler anomalies to the west and central portions, an El Niño-like pattern, presents a positive PDO value.) But the PDO does not represent sea surface temperature in the North Pacific, because the spatial pattern discussed in the example has occurred at various sea surface temperatures over the years. Refer to the comparison of the PDO index to the sea surface temperature anomalies of the same region in the North Pacific here.

Briefly, the Pacific Decadal Oscillation is a lagged El Niño-Southern Oscillation signal that is influenced by the sea level pressure and wind patterns of the North Pacific. More information about what the PDO represents, and more importantly what it doesn’t represent, can be found here, here and here.

Those studies of that use the PDO when studying the multidecadal variations in the North Pacific overlook a very important fact—that the North Pacific also has a multidecadal signal that can be presented very simply by detrending the sea surface temperature anomalies of the North Pacific north of 20N. (We exclude the tropical North Pacific to avoid the direct signals from El Niño and La Niña events.) That is, just like the natural variability of the North Atlantic, the multidecadal variations in the sea surface temperatures of the North Pacific can contribute to global warming or suppress it—(assuming that a manmade global warming signal exists in the sea surface temperature data, and there is evidence that warming of the oceans is natural. See “The Manmade Global Warming Challenge” [42MB].)

Detrended North Pacific (20N-65, 100E-100W) and North Atlantic (0-70N, 80W-0) sea surface temperature anomaly data are compared in Figure 2, using the HADSST3 sea surface temperature dataset. The amplitudes of the variations in the North Pacific sea surface temperatures are almost as strong as those in the North Atlantic, and the variations in the two ocean basins can run in and out of phase with one another. Most notably, the rise in the North Pacific data stopped in the early 1920s and dropped for a decade before resuming the climb again. And the North Atlantic began its mid-20^th century decline before the North Pacific. In recent years, the North Pacific data appears that it might have begun a new decline period, while it’s too early to tell with the North Atlantic data.

Figure 2

But we have to keep in mind that the data in Figure 2 has been detrended to help show the multidecadal variations. Figure 3 presents the same two subsets in their standard form—that is, it has not been detrended. Both datasets show multidecadal periods of flat temperatures before they cool sharply, and there’s no reason to think the upcoming period won’t start the same way—flat for a while before a dip. Then again, Mother Nature does what Mother Nature wants to do.

Figure 3

For those interested, the following links present the same graphs as Figures 2 and 3 but using NOAA’s ERSST.v3b data and the Hadley Centre’s HADISST data.

ERSST.v3b: Figure 2 and Figure 3.

HADISST: Figure 2 and Figure 3.

So, the natural variations in the sea surface temperatures of the North Pacific must also be factored into discussions of past and future global warming—though they are typically overlooked because they are usually expressed in the abstract form of the PDO.

We’ll provide comparisons of the North Atlantic and North Pacific data for the 3 datasets later in this post, but first…

WE CAN’T FORGET ABOUT THE SOUTHERN HEMISPHERE

The sea surface temperature data of the Southern Hemisphere also show multidecadal variations. Refer to Figure 4. They’re simply of a lesser amplitude than the two larger ocean basins in the Northern Hemisphere.

Figure 4

Figure 4 with ERSST.v3b data is here, and with HADISST data, it’s here.

The problem: there is so little long-term source data in the Southern Hemisphere that we really can’t define those multidecadal variations.

Are there multidecadal variations in the sea surface temperatures of the Southern Ocean surrounding Antarctica? We don’t know. We only have a reasonable amount of data there starting in the satellite era, about 1982, and it shows the sea surface temperatures of the Southern Ocean were flat for a couple of decades and then suddenly cooled around 2005, as shown here.

But NOAA doesn’t use satellite-based data in their ERSST.v3b dataset. In fact, they originally included it but then removed it because it changed the ranking of the warmest year in their combined land+sea surface temperature product—they didn’t want 1998 to be comparable to or a couple hundredths of a deg C warmer than 2005. And the Hadley Centre doesn’t use satellite-based data either in their HADSST3 data, shown in Figure 4.

The long-term data is so sparse in the Southern Hemisphere that it really serves no purpose to break out the individual basins there for this post. The following animation includes four maps that show which cells have sea surface temperature data in the Septembers of 1870, 1900, 1955 and 2010. Those cells colored white have no data. The dataset is the ICOADS sea surface temperature data, which is the source data for the ERSST.v3b, HADISST and HADSST3 datasets. Ship tracks are visible in the early maps. Unfortunately, there wasn’t a lot of ship traffic in the Southern Hemisphere. Even in September 2010 there were few temperature samples south of 45S. (You might need to click the animation to start it.)

Animation 1

Figure 5 presents the HADSST3-based sea surface temperature anomalies for the North Atlantic, North Pacific and Southern Hemisphere in their standard form—without the detrending—but still smoothed with the 61-month filters. There are two very obvious periods in the data, and the break point is at about 1910. After 1910, the three subsets show many differences in the variations over multidecadal periods. Before 1910, they all more or less agree. We can’t blame that early alignment on the base years used for anomalies. I used 1955 to 2010 for base years, not 1870 to 1910. Did something cause all of the ocean basins to cool in unison from 1870 to 1910? Or is the source data so sparse from 1870 to 1910 and has it been adjusted so much that it all seems to align during that period? The latter sounds more realistic to me.

Figure 5

The HADISST data, Figure 6, shows the same basic alignment during the first 4 decades, but with less cooling, but the ERSST.v3b data, Figure 7, shows differences between the subsets even during the initial cooling period from 1870 to 1910.

Figure 6

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Figure 7

Does that indicate that ERSST.v3b is a better dataset before 1910? No, it simply indicates NOAA used a different method to infill the data during that period than was used by the Hadley Centre for HADISST. (HADSST3 is not infilled.) Or in other words, it simply gives us results that are more along the lines we would expect.

COMPARISONS OF ERSST.v3b, HADISST, AND HADSST3 DATA

Let’s start with the detrended North Atlantic sea surface temperature anomalies, Figure 8. Considering that the HADSST3 data haven’t been infilled while the other two datasets have been, the three datasets track each other remarkably well. There are some occasional divergences, but, all in all, they follow one another.

Figure 8

The reason: the North Atlantic has the most complete long-term source data of all the ocean basins. And as NOAA notes on their AMO FAQ webpage:

Most of the Atlantic between the equator and Greenland changes in unison. Some area of the North Pacific also seem to be affected.

The North Atlantic sea surface temperature anomaly data (not detrended) are shown in Figure 9. Looking at the early data, the ERSST.v3b data (which has been infilled) matches the earlier decline exhibited by the HADSST3 data (which hasn’t been infilled). On the other hand, the infilling used in the HADISST data did not create as much cooling during that period. Was the ERSST.v3b data infilled so that it better recreated the greater cooling shown in the HADSST3 data?

Figure 9

Figure 10 is the reconstruction comparison of the detrended North Pacific sea surface temperature anomalies. There are many more differences between the ERSST.v3b, HADISST and HADSST3 datasets in this ocean basin. The differences in the detrended HADISST data and the other two are significant from 1900 to 1920—with the HADISST data not taking a major a dip and rebound. The detrended ERSST.v3b data diverges from the other two from the early 1930s to the early 1960s.

Figure 10

Comparing the North Pacific sea surface temperature anomalies without the detrending, Figure 11, we can see that the ERSST.v3b data is the outlier before 1900 and from the early 1920s to about 1940. Does this make ERSST.v3b data wrong in the North Pacific during those two periods? No again. NOAA simply used a different method to infill missing data than the Hadley Centre for its HADISST data, and in this instance, those methods provided results that were different than the other two.

Figure 11

Now for the Southern Hemisphere: The detrended sea surface temperature anomalies for the three datasets are shown in Figure 12. There are few periods of agreement between the 3 reconstructions. Because HADISST uses satellite-based data since the early 1980s, it diverges from the other two after the late 1990s. That is likely caused by the better coverage of the high latitudes of the Southern Hemisphere (the waters surrounding Antarctica), where sea surface temperatures have cooled.

Figure 12

In its standard form, the three renditions of the Southern Hemisphere sea surface temperature data agree with one another only for a few decades—from the late 1960s to the late 1990s—but that’s likely the result of the base years used for anomalies. As opposed to the other two datasets, the HADISST data shows little cooling from 1870 to the about 1920—similar to the Northern Hemisphere data. And there’s little agreement with the amount of warming that took place from the 1920s to the early 1940s. Near the end of the data, the HADISST data clearly diverges from the ERSST.v3b and HADSST3 data. As discussed above, HADISST uses satellite-based data starting in the early 1980s, so the recent divergence in the HADISST data is likely the result of the better sampling in the high latitudes of the Southern Hemisphere, where it’s cooling. Note also how the ERSST.v3b data appears to have continuous warming from 1910 to present with a “World War II” blip imposed on it. On the other hand, the two Hadley Centre datasets show warming from 1910 to the early 1940s, and then a flat temperature period until the mid-1960s.

Figure 13

CLOSING TO THE DISCUSSION OF MULTIDECADAL VARIABILITY

Detrending long-term sea surface temperature data is a way to illustrate that there are multidecadal variations in the sea surface temperatures of the North Pacific and Southern Hemisphere oceans—in addition to the multidecadal variations in North Atlantic. The strength of the variations in the North Pacific data might be less than those exhibited in the North Atlantic, and they can run in and out of synch with the North Atlantic, but the variations in the North Pacific are very strong. In the Southern Hemisphere, there appear to be multidecadal variations in two of the long-term reconstructions, but, based on the limited amount of data we have there, the multidecadal variations are weak by comparison to those in the Northern Hemisphere. Unfortunately, the data is so sparse in the Southern Hemisphere that we really have no idea about how, where and why those multidecadal variations exist.

Detrending is also a way to highlight the similarities and differences between the three long-term reconstructions of sea surface temperatures. And outside of the North Atlantic, there are more differences than similarities. In the North Pacific, the differences between the three reconstructions are not enough to rule out the existence of multidecadal variations there. In fact, the multidecadal variations are quite strong in all three reconstructions. On the other hand, the methods used by NOAA to infill their ERSST.v3b data suggest the sea surface temperatures of the Southern Hemisphere may have warmed gradually without the multidecadal variations exhibited in the two Hadley Centre products.

SPATIAL COVERAGE IS NOT THE ONLY PROBLEM WITH THE EARLY SEA SURFACE TEMPERATURE DATA

In addition to poor sampling of the global oceans, the reconstruction of long-term sea surface temperature data presented researchers with another problem. Temperature sampling methods changed with time. Refer to Folland and Parker (1995) Correction of Instrumental Biases in Historical Sea Surface Temperature Data. Steve McIntyre has a few posts about the corrections. Refer to his posts since 2005:

Changing Adjustments to 19th Century SST

And

Buckets and Engines

And

The Team and Pearl Harbor

And:

Lost at Sea: the Search Party

And

Lost at Sea.

Since the early 2000s, ARGO floats have measured sea surface temperatures when they bob to the surface at 10-day intervals. (I believe ARGO floats are included in the ICOADS source data.) Satellite-based data are used only in HADISST and the shorter-term (November 1981 to present) Reynolds OI.v2 datasets. Stationary buoys were deployed starting in the 1980s in the tropical oceans as part of the Tropical Atmosphere-Ocean (TAO) project—the tropical Pacific was first to receive the buoys, and their installation was complete in the early 1990s. Temperature measurements from ship inlets have been available since the early 1920s, but their use was more common starting in the 1940s. Buckets of different types (canvas, wood), with different heat losses, were tossed over the sides of ships, then retrieved, and a thermometer was placed in the bucket of water as it rested on deck. The transition of the different types of buckets in the late 1930s to early 1940s is said to explain the sudden rise then in the source data. Refer to the comparison of global sea surface temperature anomalies for the 3 reconstructions and the source dataset in Figure 14.

Figure 14

Those “bucket corrections” brought the sea surface temperature data into line with the Night Marine Air Temperature (NMAT) data, which is illustrated by the MOHMAT data in Figure 15.

Figure 15

But you have to keep in mind the Night Marine Air Temperature data is also adjusted or corrected, and it does not include all of the Marine Air Temperature data. As its name suggests, it only represents the nighttime readings. The daytime readings were thought to include a type of heat island effect and those observations were excluded. See Figure 16, which compares the global MOHMAT night marine air temperature to the source ICOADS marine air temperature data. A reduction in nighttime readings during World War II appears to the cause of the spike in the source data then. And I will assume the same logic applies to the correction of the inconveniently warm marine air temperature data in the late 1800s.

Figure 16

In short, there have been so many adjustments to the sea surface temperature data before the early 1940s that we really have no idea how much it warmed from the 1910s to the 1940, or, just as importantly, we have no idea how much it cooled from the late 1800s to about 1910. There’s one thing for sure: climate models cannot simulate the cooling that took place then. See Figure 17. And as a result, they fail to simulate the warming that took place from the 1910s to the 1940s.

Figure 17

And if climate models can’t explain the warming from 1910 to the early 1940s, they cannot be used to claim that manmade greenhouse gases caused the warming that took place from the mid-1970s to present.

A COUPLE OF QUICK NOTES ABOUT THE PAUSE IN GLOBAL WARMING

It should be very obvious that the greatest warming of sea surface temperatures took place in the Northern Hemisphere. Because land surface air temperatures mimic and exaggerate the warming of sea surface temperatures, land surface temperatures in the Northern Hemisphere also warmed much more than those in the Southern Hemisphere.

The recent study Balmaseda et al (2013) notes that while the warming of sea surface temperatures have paused, the oceans at depth continue to warm—according to computer model simulations of ocean heat content and according to a data- and computer model-based reanalysis. As a recent post by Dana Nuccitelli at SkepticalScience notes, there are other computer model-based studies that suggest the same thing. I’m not sure why anyone would believe climate models since they do not model ocean processes correctly. Refer to the discussion of Guilyardi et al [2009] here. Models can’t simulate ENSO, but now model simulations of ENSO are being used to explain the lack of sea surface temperature warming and the assumed continued warming at ocean depths.  And the true-blue believers in hypothetical human-induced global warming at SkepticalScience choose to believe the climate models.  Go figure.

And as illustrated and discussed in the post Ocean Heat Content (0 to 2000 Meters) – Why Aren’t Northern Hemisphere Oceans Warming During the ARGO Era?, the NODC’s annual ARGO-era ocean heat content for the North Atlantic shows little to no warming to depths of 2000 meters and shows cooling to depths of 700 meters, Figure 18. Even worse, in the North Pacific, the ocean heat content shows cooling to depths of 700 and 2000 meters, Figure 19.

Figure 18

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Figure 19

Also, my standard presentations of the East Pacific sea surface temperature anomalies and those of the Atlantic, Indian and West Pacific oceans provide a simple but logical explanation for why the warming of global surface temperatures has slowed to a crawl.

As we all know, sea surface temperatures for the East Pacific have not warmed since the November 1981 start of the Reynolds OI.v2 dataset, Figure 20.

Figure 20

On the other hand, the 1986/87/88 and 1997/98 El Niños released enough naturally created warm water from below the surface of the tropical Pacific to raise sea surface temperatures of the Atlantic, Indian and West Pacific oceans about 0.28 deg C from the early 1980s to the 2000s. In other words, those two El Niños caused the vast majority of the long-term warming of sea surface temperatures since the start of the satellite era. Sea surface temperatures were flat again until the 2009/10 El Niño, and that El Niño only released enough naturally created warm water to warm sea surface temperatures in the Atlantic, Indian and West Pacific oceans about 0.04 deg C. Simple as that.

Figure 21

Refer again to “The Manmade Global Warming Challenge” [42MB] for a further discussion of the natural warming of the global oceans.

CLOSING TO THE LATTER PART OF THIS POST

Researchers have attempted to reconstruct the sea surface temperatures of the global oceans. The actual temperatures in the early part of the record, before 1950, will remain somewhat of a mystery because of the limited amount of source data and the amounts the source data have been adjusted to accommodate changes in sampling methods. Many times you’ll find articles in scientific journals that exclude sea surface temperature data before 1950 due to the uncertainties of the early data. This post should have helped you understand why those uncertainties exist.

I presented a quote from Kevin Trenberth earlier in this post, in which he blames the IPCC for failing to acknowledge the contribution of natural variability to the recent warming of global surface temperatures. I found that curious because Kevin Trenberth was a lead author of the IPCC’s 3^rd and 4^th Assessment Reports. Is he blaming himself?

“One of the things emerging from several lines is that the IPCC has not paid enough attention to natural variability, on several time scales,” he says, especially El Niños and La Niñas, the Pacific Ocean phenomena that are not yet captured by climate models…

Look again at Figure 20 and 21 and then contemplate the quote attributed to Kevin Trenberth. Will the IPCC and its lead authors eventually acknowledge that El Niño and La Niña events are responsible for the warming of sea surface temperature and ocean heat content over the last 3+ decades? I’m not holding my breath.

Nor am I holding my breath for the next strong El Niño.  Without it, global sea surface temperatures should continue to remain flat—until the multidecadal variations in the sea surface temperatures of the North Atlantic start their decline.

SOURCE

The data and model outputs presented in this post are available through the KNMI Climate Explorer.

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UPDATE:  On the cross post at WattsUpWithThat, a number of people have asked for a copy of this post in pdf form. A copy is available here [Less than 1MB].

If you found this post informative, you may also be interested in a copy of my ebook Who Turned on the Heat?, which is only available here in pdf form for US$8.00. Or if your name is Big Oil,  a tip or donation of a dollar or two here would be much appreciated.

Thanks, Bob Tisdale

UPDATE: I’ve added an animation to the end of the post.  It illustrates the changes in specific humidity anomalies in response to  the 1997/98 El Niño and the 1998-01 La Niña.

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The UKMO Hadley Centre created a global surface (ocean and land) humidity dataset that runs from 1973 to 2003. It’s known as HadCRUH. This humidity dataset was introduced in Katharine Willett’s PhD thesis, Creation and Analysis of HadCRUH: a New Global Surface Humidity Dataset, and further documented in the 2008 Willett et al paper Recent Changes in Surface Humidity: Development of the HadCRUH Dataset. It was also the observations-based dataset used in Willett et al (2007) Attribution of Observed Surface Humidity Changes to Human Influence. We’ll call the last paper the “Willett et al attribution paper” to differentiate it from the others.

The HadCRUH data are available through the KNMI Climate Explorer in specific humidity (g/kg), Figure 1, and relative humidity (%) forms. I have not presented the relative humidity data in this post.

Figure 1

The abstract for the Willett et al attribution paper reads:

Water vapour is the most important contributor to the natural greenhouse effect, and the amount of water vapour in the atmosphere is expected to increase under conditions of greenhouse-gas induced warming, leading to a significant feedback on anthropogenic climate change. Theoretical and modelling studies predict that relative humidity will remain approximately constant at the global scale as the climate warms, leading to an increase in specific humidity. Although significant increases in surface specific humidity have been identified in several regions, and on the global scale in non-homogenized data, it has not been shown whether these changes are due to natural or human influences on climate. Here we use a new quality-controlled and homogenized gridded observational data set of surface humidity, with output from a coupled climate model, to identify and explore the causes of changes in surface specific humidity over the late twentieth century. We identify a significant global-scale increase in surface specific humidity that is attributable mainly to human influence. Specific humidity is found to have increased in response to rising temperatures, with relative humidity remaining approximately constant. These changes may have important implications, because atmospheric humidity is a key variable in determining the geographical distribution and maximum intensity of precipitation, the potential maximum intensity of tropical cyclones, and human heat stress, and has important effects on the biosphere and surface hydrology.

We know that climate models can’t properly simulate the natural processes that cause sea surface temperatures to warm, so their attribution of the rise in specific humidity to human influence is questionable.

What I found remarkable about the Willett et al attribution paper was that sea surface temperatures were never mentioned, though papers about sea surface temperature were cited.

Figure 1 presents the global specific humidity anomalies based on the HadCRUH dataset for the full term of the data. As shown, the dataset unfortunately ends in December 2003. The effects of the 1986/87/88 and 1997/98 El Niños stand out like sore thumbs, and the response to the 1973-76 La Niña is tough to miss, as is the apparent impact of the 1976 Pacific Climate Shift.

In many respects, the specific humidity data looks like noisy sea surface temperature data. Let’s see how closely they compare.

The last sentence of the abstract for the Willett et al (2008), the description paper, reads:

A strong positive bias is apparent in marine humidity data prior to 1982, likely owing to a known change in reporting practice for dewpoint temperature at this time. Consequently, trends in both specific and relative humidity are likely underestimated over the oceans.

So it’s best to exclude the early data in the comparisons that follow. And the year 1982 makes it convenient to compare the specific humidity data to Reynolds OI.v2 sea surface temperature data , which starts in November 1981.

COMPARISON TO GLOBAL SEA SURFACE TEMPERATURES

Figure 2 compares the global HadCRUH specific humidity anomalies to Reynolds OI.v2 sea surface temperature anomalies. It should really come as no surprise that specific humidity anomalies mimic the warming trend and yearly variations in global sea surface temperature anomalies—the oceans and seas cover about 70% of the surface of our planet and most of the moisture in the atmosphere comes from the oceans. Note that I did not have to scale the sea surface temperature data, and that the trends are remarkably similar.

Figure 2

We know that after 2003 global sea surface temperatures have cooled. Has global specific humidity also dropped?

Figure 3

Based on the graph of global specific humidity over the oceans, Figure 4, from the June 2012 NOAA Climate Watch Magazine article State of the Climate: 2011 Humidity, it appears global specific humidity has declined over the last decade.

Figure 4

EAST PACIFIC REGIONAL SPECIFIC HUMIDITY VERSUS THE REST OF THE WORLD

For the last couple of years, I’ve broken the global oceans down into subsets to illustrate the impacts of El Niño and La Niña events on satellite-era sea surface temperatures. First, the sea surface temperature anomalies of the East Pacific have not warmed in 31 years. Second, we’ve also illustrated and discussed how the sea surface temperatures of the Atlantic, Indian and West Pacific Oceans warm in steps, how the steps are caused by the release of naturally created warm water from beneath the surface of the tropical Pacific during strong El Niño events, and how the warm water that’s left over from those El Niños prevents the sea surface temperatures in that region from cooling proportionally during the trailing La Niñas. And we’ve discussed how the ocean heat content of the tropical Pacific confirms that El Niño events were fueled naturally. If this discussion is new to you, refer to illustrated essay “The Manmade Global Warming Challenge” [42MB].

So it probably won’t come as a surprise to you to learn that the regional land+ocean specific humidity for the coordinates of the East Pacific (90S-90N, 180-80W) mimics the sea surface temperature anomalies of the East Pacific Ocean from pole to pole—same coordinates. See Figure 5.

Figure 5

And it also won’t be surprising that the regional land+ocean specific humidity anomalies for the Atlantic, Indian and West Pacific (90s-90N, 80W-180) also rise in ENSO-induced steps in responses to the naturally created warm water that was released from below the surface of the tropical Pacific during the 1986/87/88 and 1997/98 El Niño events.

Figure 6

The upward shifts in the regional land+ocean specific humidity anomalies for the Atlantic, Indian and West Pacific (90s-90N, 80W-180) stand out quite plainly on their own, Figure 7.

Figure 7

CLOSING

Hopefully in the future I’ll take the time to create an animation of global specific humidity maps, so that we can watch the response of the specific humidity anomalies to ENSO. Figure 8 is a global map of specific humidity anomalies for the period of July 1997 to June 1998. It captures the peak of the 1997/98 El Niño. And it also gives us an idea of the areas without data.

Figure 8

With the decrease in specific humidity over the past decade, it’s kind of odd that alarmists keep telling us that precipitation (rainfall and snow) is increasing and hurricanes are getting stronger because of global warming. Do they bother to check data? Obviously not.

Attribution papers, like Willett et al (2007) Attribution of Observed Surface Humidity Changes to Human Influence, rely on a climate models that cannot simulate the natural processes (ENSO) that have caused the oceans to warm and, in turn, have caused the variations and long-term rise in specific humidity.

How poorly the models simulate sea surface temperature was presented in the following model-data comparison posts:

CMIP5 Model-Data Comparison: Satellite-Era Sea Surface Temperature Anomalies

And for the older CMIP3 version models:

Part 1 – Satellite-Era Sea Surface Temperature Versus IPCC Hindcast/Projections

And

Part 2 – Satellite-Era Sea Surface Temperature Versus IPCC Hindcast/Projections

UPDATE

The following is an animation of global specific humidity anomaly maps during the 1997/98 El Niño and 1998-01 La Niña. Each map presents the average anomalies over a 12-month period. It starts with the period of January 1996 to December 1996, and is followed by the map for the period of February 1996 to January 1997, and so on, progressing in 1-month increments, through the map for the period of January to December 2001. The 12-month averages are used to reduce any seasonal component and weather noise.  The animation is 4MB. You may need to click it to start it.

Animation 1

About 90 percent of this extra energy goes into the oceans. But meteorologist Roger Pielke Sr. of the University of Colorado in Boulder says he would like to understand why more heat is going into the deep ocean. “Until we understand how this fundamental shift in the climate system occurred,” says Pielke, “and if this change in vertical heat transfer really happened, and is not just due to the different areal coverage and data quality in the earlier years, we have a large gap in our understanding of the climate system.”

These large changes in ocean content reveal that the Earth’s surface is not a great place to look for a planetary energy imbalance. “This means this heat is not being sampled by the global average surface temperature trend,” he says. “Since that metric is being used as the icon to report to policymakers on climate change, it illustrates a defect in using the two-dimensional field of surface temperature to diagnose global warming.”

David Appell’s entire article about the recent pause in global warming is worth a read. It was also the topic of Judith Curry’s post more on the ‘pause’. There, in a comment yesterday, Roger Pielke Sr. provided his complete answer to David Appell’s interview question. Roger was also kind enough to email me his full reply with the italics, underlined and boldface text intact.  It’s as follows:

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 Hi David

 Here is my reply to your question

What do you think of Trenberth’s recent paper on ocean warming (attached)?

Balmaseda et al, Distinctive climate signals in reanalysis of

global ocean heat content, GRL

They obtain an ocean warming, for 2000-2009, of 1.19 W/m2.

Does that change any of your concerns about models overestimating net

radiative forcing, such as you wrote in Physics Today in 2007 (also

attached)?

My Answer

1. The recognition that ocean heat content changes can be used to diagnose the global radiative imbalance in Watts per meter squared, that I discussed in my paper

Pielke Sr., R.A., 2003: Heat storage within the Earth system. Bull. Amer. Meteor. Soc., 84, 331-335. http://pielkeclimatesci.files.wordpress.com/2009/10/r-247.pdf

is applied in the Balmaseda et al 2013 paper. This, as I reported in my Physics Today article, is the much more robust approach to assess global warming and cooling, than using the global annual average surface temperature trend.

The Balmaseda et al paper is a step forward in understanding the changes of heat content.

2. However, there are substantive, unanswered questions that their paper introduces.

(i) First, they report that

“In the last decade, about 30% of the warming has occurred below 700 m.”

This change in heat content is a marked difference from what they report for the earlier years as illustrated in their Figure 1. They can only speculate on how this could have occurred; i.e. they write [boldfaced highlight added]

“….that changes in the atmospheric circulation are instrumental for the penetration of the warming into the ocean, although the mechanisms at work are still to be established. One possibility suggested by Lee and McPhaden [2008], is related to the modified subduction pathways in response to changes in the subtropical gyres resulting from changes of the trade winds in the tropics (Figure S04), but whether as low frequency variability or a longer term trend remains an open question. The 2000–2006 warming trend is likely associated with the weakening of the Atlantic Meridional Overturning Circulation (MOC) in both experiments (see BMW13).”

Until we understand how this fundamental shift in the climate system occurred  (and if this change in vertical heat transfer really happened, and is not just due to the different areal coverage and data quality in the earlier years), however, we have a large gap in our understanding of the climate system.

(ii)  Moreover, how could this heat be transferred to depths below 700m without being been seen in the upper 700m of the ocean? [and this is a question also on the transfer of heat to between 300m and 700m without being seen in the upper 300m].

This absence of observable heat transfer through the upper 300m of the ocean is an issue that must be resolved.

3. There are also major implications for their findings even if they are robust.

(i) First, they report on a rate of heating that reads

the latest decade being significantly higher (1.19 ± 0.11 W m-2).

While, this is larger than found in the past,  it is still less than the best estimate of the global average radiative forcing reported in the IPCC 2007 report (1.6 ± 0.6 to 2.4 W m-2 total net anthropogenic plus  0.12 ±  0.06 to 0.30 W m-2 from solar irradiance changes).

Since their reported diagnosed radiative imbalance for the last decade is 1.19 ± 0.11 W m-2 –  which includes both the radiative forcings and all of the feedbacks (including from water vapor), this indicates that either the IPCC best estimate of the total radiative forcings by the IPCC is in error, and/or the radiative feedbacks in the climate system are a net negative.

(ii) Another very significant conclusion of their study, if it is correct, is that when they report that

about 30% of the warming has occurred below 700 m.

[and from their Figure 1, the percentage below 300m since 2003 is clearly well above 50%!]

this means that this heat is not being sampled by the global average surface temperature trend.

Since that metric is being used as the icon to report to policymakers on climate change (i.e. paraphrasing from other sources “we need to remain below a +2C change”), it illustrates a defect in using the two dimensional field of surface temperature to diagnose global warming.

 I discuss this in my post

Torpedoing Of The Use Of The Global Average Surface Temperature Trend As The Diagnostic For Global Warming. http://pielkeclimatesci.wordpress.com/2011/09/20/torpedoing-of-the-use-of-the-global-average-surface-temperature-trend-as-the-diagnostic-for-global-warming/

(iii)  Moreover, they write,

“La Niña events and negative PDO events could cause a hiatus in warming of the top 300 m while sequestering heat at deeper layers.”

If this is a real effect, than this is a muting of the radiative effect as this deep layer warming is unlikely to be reemitted back into the atmosphere in short time periods in large amounts (of Joules) as it would diffuse horizontally and vertically, at depth, in the ocean.

(iv) Also, the latest real world measurement of upper ocean heat content; [see the attachment in my e-mail from http://oceans.pmel.noaa.gov/]  continues to show, little if any significant recent warming.

(v) Finally, with respect to the change in slope, this occurred when the ARGO network achieved world-wide coverage. This raises the suspicion  that it is the date quality and coverage that remains more of an issue before 2003 than concluded in Balmaseda et al paper when they excluded the ARGO data.

Please let me know if you have any follow up questions. Thank you for the opportunity to comment.

Best Regards

Roger Sr.

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CLOSING

When Roger wrote [my boldface]…

Until we understand how this fundamental shift in the climate system occurred (and if this change in vertical heat transfer really happened, and is not just due to the different areal coverage and data quality in the earlier years), however, we have a large gap in our understanding of the climate system.

…the following graphs from the post NODC’s Pentadal Ocean Heat Content (0 to 2000m) Creates Warming That Doesn’t Exist in the Annual Data – A Lot of Warming came to mind.

Kind of odd that the NODC’s annual ocean heat content data for 0-2000 meters, Figure 1, should warm hand in hand with the data for 0-700 meters from 1970 to 2003.

Figure 1

But then as soon as the ARGO floats are deployed and have close to full coverage of the global oceans, the datasets diverge, Figure 2.

Figure 2

Does anyone want to speculate about why the NODC removed their long-term annual ocean heat content for the depths of 0-2000 meters from their website?

The following is a Global map of Reynolds OI.v2 Sea Surface Temperature (SST) anomalies for April 2013. It was downloaded from the NOMADS website. The contour levels are set at 0.5 deg C, and white is set at zero.

April 2013 Sea Surface Temperature (SST) Anomalies Map

(Global SST Anomaly = +0.234 deg C)

MONTHLY OVERVIEW

The sea surface temperature anomalies for the NINO3.4 region in the eastern equatorial Pacific (5S-5N, 170E-120E) are a commonly used index for the strength, frequency and duration of El Niño and La Nina events. We keep an eye on the sea surface temperatures there because El Niño and La Niña events are the primary cause of the yearly variations in global sea surface temperatures AND they are the primary cause of the long-term warming of global sea surface temperatures over the past 30 years. See the discussion of the East Pacific versus the Rest-of-the-World that follows.

Monthly NINO3.4 sea surface temperatures warmed about 0.1 deg C since last month. They’re presently at about zero deg C. At zero they’re obviously well within El Niño-Southern Oscillation (ENSO)-neutral conditions, meaning they’re not El Niño or La Niña conditions. Also refer to the discussion of the weekly NINO3.4 data near the bottom of the post, because they’re continuing to warm.

Global Sea Surface Temperature anomalies warmed a little (+0.021 deg C) from March to April, with both hemispheres warming. The ocean basins that cooled were the North Atlantic, Indian, Arctic and Southern Oceans. The monthly Global Sea Surface Temperature anomalies are presently at +0.234 deg C.

(1) Global Sea Surface Temperature Anomalies

Monthly Change = +0.021 deg C

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(2) NINO3.4 Sea Surface Temperature Anomalies

(5S-5N, 170W-120W)

Monthly Change = +0.093 deg C

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THE EAST PACIFIC VERSUS THE REST OF THE WORLD

The East Pacific and the Rest-Of-The-World (Atlantic-Indian-West Pacific) datasets were first discussed in the post Sea Surface Temperature Anomalies – East Pacific Versus The Rest Of The World, and were discussed a few months later in How Can Things So Obvious Be Overlooked By The Climate Science Community?

They were also discussed in great detail in my recently published book Who Turned on the Heat? The Unsuspected Global Warming Culprit, El Niño-Southern Oscillation. The Updated Free Preview includes the Table of Contents; the Introduction; the beginning of Section 1, with the cartoon-like illustrations; the discussion About the Cover; and the Closing. Also see the blog post Everything You Every Wanted to Know about El Niño and La Niña… for an overview. The book is only US$8.00. Please click here to buy a copy. (Paypal or Credit/Debit Card. You do not need to open a PayPal account.)

In the following two graphs, both datasets have been adjusted for the impacts of volcanic aerosols. I’m considering eliminating the volcano adjustments, because they add very little to the discussion. In fact, some persons use those adjustments as an excuse to disregard the obvious.

The global oceans were divided into these two subsets to illustrate a couple of facts. First, the linear trend of the volcano-adjusted East Pacific (90S-90N, 180-80W) Sea Surface Temperature anomalies since the start of the Reynolds OI.v2 dataset is basically flat. That is, the East Pacific hasn’t warmed in 31+ years. The East Pacific is not a small region. It represents about 33% of the surface area of the global oceans. The East Pacific linear trend varies very slightly with each monthly update. But it won’t vary significantly between El Niño and La Niña events.

(3) Volcano-Adjusted East Pacific Sea Surface Temperature (SST) Anomalies

(90S-90N, 180-80W)

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And second, the volcano-adjusted Sea Surface Temperature anomalies for the Rest of the World (90S-90N, 80W-180) rise in very clear steps, in response to the significant 1986/87/88 and 1997/98 El Niño/La Niña events. It also appears as though the Sea Surface Temperature anomalies of this dataset may have made another upward shift in response to the 2009/10 El Niño and 2010/11 La Niña events. For those who are interested in the actual trends of the Sea Surface Temperature anomalies between the 1986/87/88 and 1997/98 El Niño events and between the 1997/98 and 2009/10 El Niño events refer to Figure 4 in Does The Sea Surface Temperature Record Support The Hypothesis Of Anthropogenic Global Warming? I further described (at an introductory level) the ENSO-related processes that cause these upward steps in the post ENSO Indices Do Not Represent The Process Of ENSO Or Its Impact On Global Temperature. And as noted above, it is discussed in detail in my recently published book Who Turned on the Heat? The Unsuspected Global Warming Culprit, El Niño-Southern Oscillation.

(4) Volcano-Adjusted Sea Surface Temperature Anomalies For The Rest of the World

(90S-90N, 80W-180)

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The periods used for the average Rest-Of-The-World Sea Surface Temperature anomalies between the significant El Niño events of 1982/83, 1986/87/88, 1997/98, and 2009/10 are determined as follows. Using the original NOAA Oceanic Nino Index (ONI) for the official months of those El Niño events, I shifted (lagged) those El Niño periods by six months to accommodate the lag between NINO3.4 SST anomalies and the response of the Rest-Of-The-World Sea Surface Temperature anomalies, then deleted the Rest-Of-The-World data that corresponds to those significant El Niño events. I then averaged the Rest-Of-The-World SST anomalies between those El Niño-related gaps.

The “Nov 2010 to Present” average varies with each update. As noted in the post Sea Surface Temperature Anomalies – East Pacific Versus The Rest Of The World, it will be interesting to see where that Sea Surface Temperature anomaly average settles out, if it does, before the next significant El Niño drives them higher.

Of course, something could shift. Will the upward ratcheting continue when the Atlantic Multidecadal Oscillation (AMO) decides to turn around and start its decline? The upward steps would not continue in the North Atlantic, but would the AMO impact the upward steps in other portions of the globe? For more information about the Atlantic Multidecadal Oscillation, refer to the post An Introduction To ENSO, AMO, and PDO — Part 2.

The Sea Surface Temperature anomalies of the East Pacific Ocean, or approximately 33% of the surface area of the global oceans, have decreased slightly since 1982 based on the linear trend. And between upward shifts, the Sea Surface Temperature anomalies for the rest of the world (67% of the global ocean surface area) remain relatively flat. As discussed in my book, anthropogenic forcings are said to be responsible for most of the rise in global surface temperatures over this period, but the Sea Surface Temperature anomaly graphs of those two areas prompt a two-part question: Since 1982, what anthropogenic global warming processes would overlook the Sea Surface Temperatures of 33% of the global oceans and have an impact on the other 67% but only during the months of the significant El Niño events of 1986/87/88, 1997/98 and 2009/10?

STANDARD NOTE ABOUT THE DATA

Other than the East Pacific and Rest-of-the-World data shown immediately above, the MONTHLY graphs illustrate raw monthly OI.v2 sea surface temperature anomaly data from November 1981 to April 2013, as it is presented by the NOAA NOMADS website linked at the end of the post. NOAA uses the base years of 1971-2000 for this dataset. I’ve added the 13-month running-average filter to smooth out the seasonal variations.

MONTHLY INDIVIDUAL OCEAN AND HEMISPHERIC SEA SURFACE TEMPERATURE UPDATES

(5) Northern Hemisphere Sea Surface Temperature (SST) Anomalies

Monthly Change = +0.033 deg C

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(6) Southern Hemisphere Sea Surface Temperature (SST) Anomalies

Monthly Change = +0.012 deg C

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(7) North Atlantic Sea Surface Temperature (SST) Anomalies

(0 to 70N, 80W to 0)

Monthly Change = -0.092 deg C

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(8) South Atlantic Sea Surface Temperature (SST) Anomalies

(0 to 60S, 70W to 20E)

Monthly Change = +0.045 deg C

Note: I discussed the (now apparently temporary) upward shift in the South Atlantic Sea Surface Temperature anomalies in the post The 2009/10 Warming Of The South Atlantic. Prior to that shift, the South Atlantic sea surface temperature anomalies had been relatively flat for about two decades. It looks as though the South Atlantic sea surface temperature anomalies are have returned to the level they were at before that surge, and where they had been since the late 1980s.

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(9) Pacific Sea Surface Temperature (SST) Anomalies

(60S to 65N, 120E to 80W)

Monthly Change = +0.078 Deg C

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(10) North Pacific Sea Surface Temperature (SST) Anomalies

(0 to 65N, 100E to 90W)

Monthly Change = +0.096 Deg C

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(11) South Pacific Sea Surface Temperature (SST) Anomalies

(0 to 60S, 120E to 70W)

Monthly Change = +0.053 deg C

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(12) Indian Ocean Sea Surface Temperature (SST) Anomalies

(60S to 30N, 20E to 120E)

Monthly Change = -0.045 deg C

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(13) Arctic Ocean Sea Surface Temperature (SST) Anomalies

(65N to 90N)

Monthly Change = -0.003 deg C

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(14) Southern Ocean Sea Surface Temperature (SST) Anomalies

(90S-60S)

Monthly Change = -0.072 deg C

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WEEKLY SEA SURFACE TEMPERATURE ANOMALIES

The NINO3.4 Sea Surface Temperature anomalies based on the week centered on May 1, 2013 continue to be above zero but well below El Niño condition. They are presently at +0.08 deg C.

(15) Weekly NINO3.4 Sea Surface Temperature (SST) Anomalies

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Global sea surface temperature anomalies have warmed a slight bit over the past week. They are at +0.256 deg C.

(16) Weekly Global Sea Surface Temperature (SST) Anomalies

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INTERESTED IN LEARNING MORE ABOUT HOW AND WHY THE GLOBAL OCEANS INDICATE THEY’VE WARMED NATURALLY?

Why should you be interested? The hypothesis of manmade global warming depends on manmade greenhouse gases being the cause of the recent warming. But the sea surface temperature record indicates El Niño and La Niña events are responsible for the warming of global sea surface temperature anomalies over the past 31 years, not manmade greenhouse gases. Scroll back up to the discussion of the East Pacific versus the Rest of the World. I’ve searched sea surface temperature records for more than 4 years, and I can find no evidence of an anthropogenic greenhouse gas signal. That is, the warming of the global oceans has been caused by Mother Nature, not anthropogenic greenhouse gases.

I’ve recently published my e-book (pdf) about the phenomena called El Niño and La Niña. It’s titled Who Turned on the Heat? with the subtitle The Unsuspected Global Warming Culprit, El Niño Southern Oscillation. It is intended for persons (with or without technical backgrounds) interested in learning about El Niño and La Niña events and in understanding the natural causes of the warming of our global oceans for the past 30 years. Because land surface air temperatures simply exaggerate the natural warming of the global oceans over annual and multidecadal time periods, the vast majority of the warming taking place on land is natural as well. The book is the product of years of research of the satellite-era sea surface temperature data that’s available to the public via the internet. It presents how the data accounts for its warming—and there are no indications the warming was caused by manmade greenhouse gases. None at all.

Who Turned on the Heat? was introduced in the blog post Everything You Ever Wanted to Know about El Niño and La Niña… …Well Just about Everything. The Updated Free Preview includes the Table of Contents; the Introduction; the beginning of Section 1, with the cartoon-like illustrations; the discussion About the Cover; and the Closing.

Please buy a copy. (Paypal or Credit/Debit Card). You do not need to have a PayPal account. Simply scroll down to the purchase option Simply scroll down to the “Don’t Have a PayPal Account” purchase option. It’s only US$8.00.

SOURCES

The Sea Surface Temperature anomaly data used in this post is available through the NOAA NOMADS website:

http://nomad1.ncep.noaa.gov/cgi-bin/pdisp_sst.sh

or:

http://nomad3.ncep.noaa.gov/cgi-bin/pdisp_sst.sh?lite=

I have not read the recent post by Dana Nuccitelli in its entirety. Based on the opening paragraph, it looks to be a comment on the McLean et al (2009) paper Influence of the Southern Oscillation on tropospheric temperature. This post is not a defense of that paper. It’s about the closing statement of Dana Nuccitelli’s post, which is clearly a falsehood. Nuccitelli writes:

If we remove the long-term warming trends, we can see once again that the short-term wiggles in the temperature data are strongly influenced by changes in ENSO.  However, the long-term global warming trends are not – they are due to the human-caused greenhouse effect.

Here’s a challenge to Dana Nuccitelli and other bloggers from SkepticalScience. You and your associates at SkepticalScience claim to have analyzed more than 12,000 peer-reviewed papers about global warming and climate change. What I present in the following should be a really easy task, because lower troposphere temperature anomalies for the mid-to-high latitudes of the Northern Hemisphere warmed in a very specific way. Surely, out of the 12,000 papers, a few of them must have addressed how lower troposphere temperatures have actually warmed.

If you believe that manmade greenhouse gases are responsible for the recent bout of global warming, please provide links to the climate model-based, peer-reviewed papers that explain:

1. How and why the lower troposphere temperature anomalies of the mid-latitudes of the Northern Hemisphere show upward shifts in response to strong El Niño events—without proportional cooling during the trailing La Niñas. That is, the RSS lower troposphere temperature anomalies for the latitudes of 20N-90N do not cool proportionally during the La Niña event of 1988/89, Figure 1, but they did warm in response to the 1986/87/88 El Niño, which caused a major portion of the long-term warming trend.

Figure 1

2. And how and why the RSS lower troposphere temperature anomalies for the latitudes of 20N-90N do not cool proportionally during the La Niña event of 1998-01, Figure 2, but they did warm significantly in response to the 1997/98 El Niño, which caused another major portion of the long-term trend.

Figure 2

It is blatantly obvious to anyone reading and comprehending those two graphs that there would be little to no long-term warming of the lower troposphere temperature anomalies for mid-to-high latitudes of the Northern Hemisphere if lower troposphere temperature anomalies had cooled proportionally during the La Niña events of 1988/89 and 1998-01.

I first discussed the warming of lower troposphere temperature data almost 4 years ago in the post RSS Time Latitude Plots Show Climate Responses That Cannot Be Easily Illustrated With Time-Series Graphs Alone. And I discussed why the lower troposphere temperature anomalies for the mid-to-high latitudes of the Northern Hemisphere do not cool proportionally during the 1988/89 and 1998-01 La Niñas in the post The ENSO-Related Variations In Kuroshio-Oyashio Extension (KOE) SST Anomalies And Their Impact On Northern Hemisphere Temperatures.

Back to Nuccitelli’s closing statement: That was the same conclusion reached in a recent video by SkepticalScience, using surface temperatures. I responded to their video with the post The Blatant Errors in the SkepticalScience Video “Global Warming over the Last 16 Years”, which includes the following YouTube video:

DON’T FORGET SEA SURFACE TEMPERATURE AND OCEAN HEAT CONTENT

Further to my challenge to Dana Nuccitelli and his associates at SkepticalScience: if you continue to believe that manmade greenhouse gases are responsible for the recent bout of global warming, please provide links to the climate model-based, peer-reviewed papers that explain how and why sea surface temperature and ocean heat content data have warmed (or not warmed) in the following ways (numbering continued from preceding section):

3. How and why the sea surface temperatures of the East Pacific (90S-90N, 180-80W) haven’t warmed in 31 years (Figure 3).

Figure 3

4. How and why the seas surface temperatures of the Atlantic, Indian and West Pacific Oceans (Figure 4) with the coordinate of 90S-90N, 80W-180, only warmed during the strong El Niño events of 1986/87/88, 1997/98 and 2009/10 and did not cool proportionally during the training La Niñas—and without those El Niño events, the sea surface temperatures there would show no warming.

Figure 4

That should be a simple task since the global oceans were only broken down into two subsets.

Moving now to ocean heat content of the tropical Pacific where the fuel for El Niño events is generated:
5. How and why the warming of the ocean heat content data for the tropical Pacific, Figure 5, is dependent on the 1973-76 and 1995/96 La Niña events, and without those La Niñas the ocean heat content for tropical Pacific would cool.

Figure 5

Still in the subject of ocean heat content:

6. How and why the warming of the ocean heat content of the North Pacific (north of the tropics) is dependent on a 2-year climate shift (1989-90), and without that climate shift, the ocean heat content for the North Pacific would cool (Figure 6).

Figure 6

I discussed the above four graphs and the natural processes that caused their warming in the illustrated essay “The Manmade Global Warming Challenge” [42MB] and in the YouTube video series “The Natural Warming of the Global Oceans” Part 1 and Part 2. And I also discussed them in great detail in my ebook Who Turned on the Heat? which is available in pdf form for only US$8.00. Who Turned on the Heat? also discusses the warming of lower troposphere temperature anomalies shown in Figures 1 and 2.

CLOSING

There’s no reason to wait for links to peer-reviewed papers from Dana Nuccitelli and his associates at SkepticalScience—links that will offer climate model-based explanations for how and why the oceans have warmed in the fashions they’ve warmed and how the lower troposphere temperature anomalies warmed as they had. The warming is dependent on ENSO, and for the ocean heat content of the North Pacific, it depends on a change in wind patterns and sea level pressure. The first problem they’ll encounter is trying to find studies based on climate models that can simulate ENSO. As far as I know, there are a sum total of…How should I put this?…none. See Guilyardi et al (2009), discussed in the post here.

I used the phrases “if you believe” and “if you continue to believe” as part of the challenges to SkepticalScience. Sea surface temperatures, ocean heat content and lower troposphere temperatures have all warmed in very specific ways in response to ENSO. Unless there are climate model-based peer-reviewed papers that explain specifically how and why those variables have actually warmed in the manners in which they’ve warmed as responses to ENSO, then parties like SkepticalScience who are promoting hypothetical manmade global warming are doing so based solely on their beliefs.

Thanks for furnishing the lovely graph of global temperature anomalies in your WMO Statement on Status of the Global Climate in 2012. I’ve reproduced it here.

The caption for it reads:

Figure 4. January–December global land and ocean surface temperature anomalies (relative to 1961–1990) for the period 1950–2012; years that started with a moderate or strong La Niña already in place are shown in blue, years that started with a moderate or strong El Niño already in place are shown in red; other years are shown in grey.

If you’re not aware, persons see the following three periods in that graph.

Just thought you’d be interested. That’s what I see, and I suspect many other persons see the same three periods in the graph. And that means no matter what you’ve written in the rest of that report, what people will see and take away from your report is that global surface temperatures warmed for a couple of decades, starting around the mid-1970s. Then surface temperatures stopped warming a decade and a half ago.

The graph that you’ve provided as part of your press release is worse. The funky blue shading at the bottom of the 2012 bar will make persons wonder what you’re trying to show with it. One thing is for sure: it draws the eye down. Odd that you should do that when you’re struggling to show global warming.

A question: The WMO recommends that the base years used for anomalies be updated every 10 years. Many organizations, such as NOAA, comply with that recommendation. They now use 1981 to 2010 as the base years for anomalies for many of their datasets. Is there any reason you continue to use 1961-1990, other than to make the temperature anomaly map look warmer? Also, the non-linear color-coded scaling of the contour intervals is very awkward.

Last, earlier this year I prepared an illustrated essay that discusses global warming. It’s titled “The Manmade Global Warming Challenge”. The preview is here [4MB] and the full essay is here [42MB]. It’s easy to read and understand. I thought you might be interested in a copy.

Sincerely,

Bob Tisdale

Before the ARGO floats were deployed, there were so few temperature and salinity observations at depths below 700 meters that the NODC does not present ocean heat content data during that period for depths of 0-2000 meters on an annual basis. That is, the NODC only presents its annual ocean heat content data for the depths of 0-2000 meters starting in 2005. The NODC’s annual ocean heat content data (0-2000 meters) for global oceans are here; for the Indian Ocean, see here; for the Atlantic Ocean, they’re here; and for the Pacific Ocean, data can be found here. The NODC now only presents its long-term data (1955 to present) for depths of 0-2000 meters in pentadal form. They had provided the long-term annual data for the depths of 0-2000 meters for a very short time period, but removed it from their website as soon as they released the pentadal data. There are two problems with the pentadal data. It mysteriously adds more than 30% to the long-term trend when compared to the formerly available annual data for those depths. (See the post here.) And the 5-year “averaging” of the pentadal data makes the dataset useless in attribution studies. 5-year filters have been used by the climate science community for years to mask responses to El Niño and La Niña events, which also have significant impacts on ocean heat content data.

So that leaves us with only 8 years of annual ocean heat content data to examine for the depths of 0-2000 meters. That’s okay. We can learn something from the 8 years of data.

Figure 1

Keep in mind, ocean heat content data is unlike surface temperature and lower troposphere temperature data. With ocean heat content data, the heat is either there or it’s not. There is no unrealized heat. Roger Pielke Sr. provided a more detailed explanation in his blog post here.

Also keep in mind that Balmaseda et al (2013) Distinctive climate signals in reanalysis of global ocean heat content (paywalled), of which Kevin Trenberth was one of the authors, began their abstract with:

The elusive nature of the post-2004 upper ocean warming has exposed uncertainties in the ocean’s role in the Earth’s energy budget and transient climate sensitivity.

That falls right in line with the period from 2005 to 2012, for which we have annual data. And as we’ll see, the warming is still elusive.

Ever since the NODC released their ocean heat content data for the depths of 0-2000 meters and published Levitus et al (2012), it seems that each time a skeptic writes a blog post or answers a question in an interview, in which he or she states that global surface temperatures haven’t warmed in “X” years, a global warming enthusiast will counter with something to the effect of: global warming hasn’t slowed because ocean heat content continues to show warming at depths of 0-2000 meters. Recently, those same people are linking Balmaseda et al (2013) and claiming the warming of ocean heat content data continues.

It is true that the NODC’s ARGO-era ocean heat content (0-2000 meters) continues to warm globally, but always recall that the ARGO data had to be adjusted, modified, tweaked, corrected, whatever, in order to create that warming. That is, the “raw” ocean heat content data for 0-2000 meters shows the decreased rate of warming after the ARGO floats were deployed. (See the post here.) Also, while the much-revised NODC ocean heat content data for 0-2000 meters might show warming globally, it shows very little warming for the Northern Hemisphere oceans since 2005. See Figure 1. Only about 7% of the warming of ocean heat content for the depths of 0-2000 meters occurred in the Northern Hemisphere from 2005 to 2012, yet the surface area of the Northern Hemisphere oceans represents about 43% of the surface of the global oceans.

Can well-mixed human-created greenhouse gases pick and choose between the hemispheres, warming one but not the other? One might think that’s very unlikely.

Something else to consider: the Northern Hemisphere warming of ocean heat content for depths of 0-2000 meters occurs in only one ocean basin, and it’s not one of the big ones.

NORTHERN HEMISPHERE OCEAN HEAT CONTENT – 0-700 AND 0-2000 METERS

Before we begin with the individual ocean basins, let’s take a look at the change in the ocean heat content of the Northern Hemisphere from 2005 to 2012, for the depth ranges of 0-700 meters and 0-2000 meters. See Figure 2. There was a comparatively minor warming in the Northern Hemisphere at depths of 0-2000 meters from 2005 to 2012. But the upper 700 meters in the Northern Hemisphere cooled. The difference is provided to show the additional warming that occurred at depths of 700 to 2000 meters.

Figure 2

NORTH INDIAN OCEAN HEAT CONTENT – 0-700 AND 0-2000 METERS

Before we begin, recall that the North Indian Ocean is not like the North Atlantic and North Pacific. The North Indian Ocean basically ends in the tropics with the Arabian Sea and the Bay of Bengal, both bordering Asia, while the North Atlantic and North Pacific have large extratropical portions. The North Indian Ocean is comparatively small for that reason.

If manmade greenhouse gases were capable of warming the global oceans, one would have to assume the warming would be similar to what’s taking place in the North Indian Ocean. As shown in Figure 3, the ocean heat content for the North Indian Ocean is warming at depths of 0-700 meters and 0-2000 meters—and at 700-2000 meters.

Figure 3

On the other hand, the ocean heat content data for the North Atlantic and North Pacific are not cooperating with the hypothetical warming of the oceans by manmade greenhouse gases.

NORTH ATLANTIC OCEAN HEAT CONTENT – 0-700 AND 0-2000 METERS

RealClimate recently published a post titled “The Answer is Blowing in the Wind: the Warming Went into the Deep End”. It’s about the Balmaseda et al (2013) paper. There Rasmus Benestad writes about the North Atlantic:

A weakening of the Atlantic meridional overturning circulation (MOC) may have played a role in the deep ocean warming.

So let’s take a look at the North Atlantic ocean heat content data. Based on the linear trend, the ocean heat content data of the North Atlantic for the depths of 0-2000 meters haven’t warmed from 2005 to 2012. See Figure 4. And the data for depths of 0-700 meters show cooling in the North Atlantic. The additional warming at the depths of 700-2000 meters (illustrated by the “difference”) was comparable to the cooling at 0-700 meters, inferring there might simply have been an exchange of heat between two depth ranges, but there is no evidence of manmade greenhouse gas-driven warming in the North Atlantic from 2005-2012.

Figure 4

Also recall that Mauritzen et al (2012) Importance of density-compensated temperature change for deep North Atlantic Ocean heat uptake (paywalled) found that while the upper 2000 meters of the North Atlantic warmed since the 1950s, the deep ocean below 2000 meters cooled, suggesting an exchange of heat between the deep ocean and the depths above 2000 meters. That cooling below 2000 meters is obviously not considered in the NODC ocean heat content data. Mauritzen et al (2012) was discussed in my post Is Ocean Heat Content All It’s Stacked up to Be? under the heading of SPEAKING OF STILL-TO-BE-DISCOVERED SUBSURFACE OCEAN PROCESSES.

NORTH PACIFIC OCEAN HEAT CONTENT – 0-700 AND 0-2000 METERS

There have been a number of blog posts about Balmaseda et al (2013) by proponents of the hypothesis of manmade global warming, including the RealClimate post linked above and at least one post at SkepticalScience. From what I can gather from those posts, Balmaseda et al (2013) are basically saying this: when La Niña events dominate, warm water is forced to depths greater than 300 meters, driven there by the stronger-than-normal trade winds associated with the La Niñas. According to the new and improved Oceanic NINO Index, starting in 2005, there have been 5 La Niña events and only 2 El Niños. Clearly, La Niña events dominated the last 8 years. Therefore, we would expect the ocean heat content of the North Pacific to be showing all sorts of excessive warming.

But the NODC’s annual ocean heat content data for the North Pacific shows cooling, Figure 5, not warming, for the depths of 0-2000 meters. And the depths of 0-700 meters have cooled at an even more drastic rate. If the stronger trade winds associated with the La Niña events have contributed to the warming of the North Pacific ocean heat content from 700-2000 meters (shown as the “difference”), then the only thing those stronger trade winds did was prevent the 0-2000 meter data from cooling as quickly as the 0-700 meter data.

Figure 5

FURTHER INFORMATION

I linked this post earlier, but I’ll link it again. For a detailed discussion of the problems with ocean heat content data refer to Is Ocean Heat Content All It’s Stacked up to Be?

For introductory discussions of how the ocean heat content data for the depths of 0-700 meters indicate the oceans warmed naturally, and discussions of the natural processes that caused the warming, refer to my illustrated essay “The Manmade Global Warming Challenge” [42MB]. And if you’re looking for a much more-detailed discussion of the natural warming of the global oceans, refer to my book Who Turned in the Heat? It was introduced in the post “Everything You Ever Wanted to Know About El Niño and La Niña”. It’s for sale in pdf form at US$8.00.

CLOSING

With their continuing failed attempts, the alarmist wing of the climate science community still has a lot of work to do to explain the warming of the global oceans, or lack thereof. If they can’t explain why the ocean heat content data of the North Atlantic and North Pacific have not warmed, they can’t claim greenhouse gases are responsible for the warming of the ocean heat content in the Southern Hemisphere. They also have problems with the long-term data, as we’ve been presenting and discussing for a few years. But first…

SkepticalScience’s Rob Painting provides a reasonable explanation of the hypothetical cause of greenhouse gas-driven warming of the global oceans in the post Observed Warming in Ocean and Atmosphere is Incompatible with Natural Variation. Painting writes (my boldface):

Arguably the most significant climate-related impact of increased concentrations of greenhouse gases in the atmosphere, is that they trap more heat in the ocean. Over the last half-century around 93% of global warming has actually gone into heating the ocean. A little-known fact is that the oceans are almost exclusively heated by sunlight (shortwave radiation) entering the surface layers. Geothermal heat emanating from deeper layers of the Earth does contribute a small amount to ocean warming but, on the time scale of decades & centuries, this contribution is effectively constant as it is determined by the rate of radioactive decay.

So how do greenhouse gases accomplish this ocean heating? This is discussed in this SkS post, but briefly; greenhouse gases radiate heat (longwave radiation) back toward the surface and, although they cannot penetrate into the ocean itself, they warm the uppermost surface of the thin cool-skin layer. The thermal gradient through this layer dictates the rate of heat loss from the (typically) warmer ocean surface, to the cooler atmosphere above. When greenhouse gases increase, more longwave radiation is directed back at the ocean surface, which warms the cool-skin layer, lowers the thermal gradient, and consequently reduces the rate of heat loss. The sum effect is that the oceans trap more of the sun’s energy and therefore warm over time.

While Painting does note that longwave radiation from greenhouse gases only impacts the top few millimeters (the skin) of the surface, he fails to consider that evaporation occurs at the surface, he fails to consider that the ocean release heat primarily through evaporation, and he fails to consider that when the ocean heat content data of the global oceans are divided into logical subsets, they indicate the oceans warmed naturally.

For almost 4 years, I’ve been illustrating how (and presenting the natural processes through which) specific La Niña events are responsible for the warming of ocean heat content in the tropical Pacific. More recently, I’ve shown that without the 1973-76 and 1995/96 La Niña events, Figure 6, the ocean heat content of the tropical Pacific would have cooled since the 1950s. It’s tough to claim manmade greenhouse gases are responsible for the long-term warming when that warming relies on only 4 years of data.

Figure 6

And I’ve been showing that the warming of the ocean heat content (0-700 meters) for the extratropical North Pacific is dependent on a 2-year shift and without that upward shift, which is likely caused by a change in wind patterns there, the ocean heat content of the North Pacific north of the tropics would also cool since the 1950s. Again, it’s tough to claim anthropogenic greenhouse gases caused the warming in this portion of the North Pacific when the ocean heat content data there would cool if you remove just 2 years of data.

Figure 7

(Note: Almost 2 decades ago Kevin Trenberth discussed the same wind pattern-based upward shift in the sea level pressure of the extratropical North Pacific. Refer to Trenberth and Hurrell (1995) Decadal coupled atmosphere-ocean variations in the North Pacific Ocean. See their Figure 6, which shows the sea level pressure of a portion of the extratropical North Pacific. One would think Trenberth should also know that same shift exists in extratropical North Pacific sea surface temperature and ocean heat content data.)

Curiously, when you combine those ocean heat content subsets for the Pacific Ocean with their different natural warming and cooling periods, Figure 8, they mimic the long-term warming of the global ocean heat content data, which alarmists happily but falsely claim is caused by manmade greenhouse gases.

Figure 8

To conclude this post, I’ll paraphrase the opening sentence of Balmaseda et al (2013):

The elusive nature of the post-2004 upper ocean warming continues to expose uncertainties in the ocean’s role in the Earth’s energy budget and transient climate sensitivity.

SOURCES

The annual ocean heat content data (0-700 meters and 0-2000 meters) presented in Figures 1 through 5 are available from the NODC webpage here. The NODC ocean heat content data for Figures 6, 7 and 8 are available through the KNMI Climate Explorer.