How strong were the recent El Niño and La Niña of the late 1990s?
In the following JPL animation, you will compare the sequence of events from 1996 through 1999 documenting one of the largest El Niño events of the century followed by a strong La Niña event. Images from Topex-Poseidon satellite are used to show changes in sea surface temperatures and in sea surface heights.
1. What does the globe on the left show?
2. What does the globe on the right show?
3. About when did the El Niño reach its maximum strength?
At the time of the maximum El Niño strength, what was the largest sea level
height anomaly in the eastern Pacific?
5. For the same time as in #'s 3 and 4, what was the greatest SST anomaly?
6. In February, 1998, southern
strong was the El Niño in terms of SST anomalies?
7. What indicates the weakening of the
El Niño and a rapid change to La Niña
conditions in May and June of 1998?
a. sea level heights rise in the central
b. sea level heights fall in the central equatorial Pacific
c. SST’s are much cooler in the Alaskan Gulf
d. SST’s are warming in the eastern tropical Pacific
8. What is the sea surface height anomaly in the eastern Pacific in January, 1999?
9. What is the SST anomaly in the eastern Pacific in January, 1999?
10. The Scripps, UCSD, website, http://meteora.ucsd.edu/~pierce/elnino/en97/en97.html
offers an interesting 3-dimensional look at the development of the 1997-98 El Niño.
From the monthly 3-D figures, about when did the actual El Niño begin (when warm water at depth begins to move eastward)?