The animation illustrates the evolution of sea surface temperature (SST) and sea surface height (SSH) anomalies (relative to the respective normal state, i.e., seasonal climatology) associated with the 2010-11 La Niña in the Pacific Ocean.  SST and SSH anomalies reflect the heat content in the mixed layer (approximately upper 50 m) and the upper ocean (approximately upper 150 m) respectively.  Warm/cold SST anomalies often are associated with high/low SSH anomalies. They provide complimentary views of the oceanic signature of climate variability such as El Niño and La Niña . La Niña is the cooling phase (in contrast to the warming phase, the El Niño) of an interannual mode of climate variability called El Nino-Southern Oscillation.  Initial cooling appeared in the eastern to central equatorial Pacific around June 2010 and grew into a relatively strong La Niña event in late 2010. The event persists beyond February 2011.

*Data: The SST data are obtained from a blended AMSR-E and MODIS  product.  The seasonal climatology of SST (derived from AVHRR Pathfinder SST for the period of 1982-2008) is subtracted from the AMSR-E and MODIS blended data to produce the anomaly.  The SSH data are from the JASON-1 and OSTM/JASON-2 satellite altimetry missions. The seasonal climatology of the SSH data is for the period of 1993-2008.