This two part series of posts provides links to 8 gif animations of the 1997/98 El Niño through the 1998/99/00/01 La Niña events. They are being provided solely as references.
YOU MAY HAVE TO CLICK ON THE ANIMATIONS TO VIEW THEM.
Animation 1 is one I’ve included in a number of posts. It illustrates the variations in global sea surface temperature anomalies before, during and after the 1997/98 El Niño and continues through the 1998/99/00/01 La Niña. The East Indian and West Pacific Oceans (60S-65N, 80E-180) are highlighted with a red box. The maps were created at the KNMI Climate Explorer, using Reynolds OI.v2 satellite-based sea surface temperature data. The animation also includes a graph that compares East Indian-West Pacific Ocean sea surface temperature anomalies to scaled NINO3.4 sea surface temperature anomalies. The NINO3.4 data (an ENSO index) has been scaled by a factor of 0.13 and it has also been shifted down 0.05 deg C to better align the two datasets at the beginning of the animation. The base years for anomalies are 1982 to 2009. The data in the graph has been smoothed with a 12-month running-average filter to reduce the noise and minimize any seasonal component in the East Indian-West Pacific data. The 12-month data filter also aligns it with the map, since each map represents a 12-month average of sea surface temperature anomalies. Using the 12-month averages in the maps has the same effect as smoothing data in a graph: it reduces the weather noise and reduces any seasonal component. In the animation, the June 1996 to May 1997 map is followed by a map that shows the average for the next 12-month period, July 1996 to June 1997. The animation continues on in sequence until the final map that shows the average sea surface temperature anomalies for the period of August 2001 to July 2002.
The next 3 animations use Animation 1 as its base. It has the sea surface temperature maps and the graphs of the NINO3.4 and East Indian-West Pacific sea surface temperature anomalies. And the animations present the data the same way, with cells representing 12-month averages, and they cover the same period of June 1996-May 1997 through August 2001-July 2002. For these animations, however, a second set of animated maps are added below the sea surface temperature maps. and those new sets present:
Animation 2: Total cloud amount anomalies
Animation 3: Precipitation anomalies
Animation 4: Sea level anomalies
And in part 2:
Animation 5: Pacific Ocean sea surface temperatures (not anomalies)
Animation 6: Lower troposphere temperature (TLT) anomalies
In addition, part two also includes animations of North Atlantic sea surface temperature anomalies.
Animation 2 compares sea surface temperature anomalies to total cloud amount anomalies. The total cloud amount anomalies are based on the ISCCP Cloud Amount data. ISCCP stands for International Satellite Cloud Climatology Project. Note the funnel shape over the Indian Ocean in the cloud amount data. That’s from a satellite blind spot in early years that impacts the anomalies. Since our focal point is the tropical Pacific, that problem in the Indian Ocean data is not a concern.
Sea Surface Temperature Anomalies (top) with Total Cloud Amount Anomalies (Note the funnel shape over the Indian Ocean. That’s from a blind spot in early years that impacts the anomalies.)
Animation 3 presents sea surface temperature anomalies with Climate Anomaly Monitoring System (CAMS) – OLR Precipitation Index (OPI) (CAMS-OPI) precipitation anomalies.
Animation 4 compares Reynolds OI.v2 sea surface temperature anomalies to an early version of the AVISO CLS sea level anomaly data.
All maps used in the animations were created at the KNMI Climate Explorer: