In my post The Latest Revisions to Ocean Heat Content Data, I provided comparisons of the recent Levitus et al (2009) Ocean Heat Content (OHC) data to other recently released reconstructions. This post compares ocean basin data from the Levitus et al (2009). The OHC data are available through the NOAA National Oceanographic Data Center here:
There is also a link to the Levitus et al (2009) paper on the webpage:
COMPARSION CHART OF OHC BY BASIN
Figure 1 is a comparison chart of the OHC for the Atlantic, Indian, and Pacific Ocean basins. This presentation does not consider the differences in the areas of the three oceans. The Pacific Ocean has more than twice the surface area of the Indian Ocean and ~60% more surface area than the Atlantic Ocean. Regardless of area, the Atlantic Ocean Heat Content rose more than the OHC of the Indian and Pacific Oceans.
AREA-ADJUSTED COMPARISON CHART
Figure 2 shows the area-adjusted OHC for the individual oceans, where the data is in terms of OHC/million sq km. The surface areas of the oceans used in Levitus et (2009) were not listed, so it’s impossible to determine if the Arctic and Southern were included in the data of the three major oceans, or if the Gulf of Mexico, Mediterranean Sea and Caribbean Sea were included in the Atlantic data. So I used the standard ocean surface areas listed in Wikipedia, but excluded the “seas” from the Atlantic: 82.4 million sq km for the Atlantic, 73.5 million sq km for the Indian, and 169.2 million sq km for the Pacific. The Atlantic Ocean heat Content has had the largest increase over the term of the data.
Adding linear trends to the area-adjusted data, Figure 3, shows that Indian and Pacific Oceans trends were fundamentally the same. It also shows that the Atlantic Ocean Heat Content rose at a rate that was more than twice that of the Indian and Pacific Oceans.
COMPARISONS OF SST ANOMALIES AND SSTs
The rise in the area-adjusted OHC for the Atlantic was unexpected, since the rise in the SST anomalies of the Indian Ocean exceeded the Atlantic and Pacific Oceans. Refer to Figure 4.
And for those wondering about actual SSTs, Figure 5 is a comparison of Atlantic, Indian, and Pacific Ocean SSTs (not anomalies). The SST of the Atlantic Ocean is ~2.5 deg C lower than the Indian and Pacific Oceans.
NORTH AND SOUTH ATLANTIC OHC
Curious about the rise in the OHC of the Atlantic, I plotted the North and South Atlantic OHC data, Figure 6. The rise in the North Atlantic OHC was obviously greater than in the South Atlantic.
Again, I do not know if the Levitus et al included the Gulf of Mexico, Mediterranean Sea and Caribbean Sea in the North Atlantic data. But in Figure 7, I assumed they were excluded. I also assumed the area of the Atlantic Ocean without the additional seas (82.4 million sq km) was evenly split between the hemispheres. The rise in the area-adjusted OHC of the North Atlantic is more than twice that of the South Atlantic. And note that the linear trend of the South Atlantic is approximately twice that of the Pacific and Indian Oceans, Figure 3.
Why did the increase in area-adjusted Atlantic Ocean OHC more than double the rise of the Indian and Pacific Oceans? This can also be seen in the “Heat Storage Per Unit Area” values presented by Levitus et al in their Table T1. Refer to Figure 8.