The latest image from NASA’s Jason oceanography satellite, taken during a 10-day collection cycle ending April 7, 2003, shows that the warm, high sea level El Niño pool of the past winter is history. The equatiorial Pacific sea surface temperatures and sea levels have returned to near-normal conditions. The image shows red areas in the north and south subtropical Pacific, (10°N(S) to 20°N(S), remnants of the disappearing El Niño, that are about 10 centimeters (4 inches) above normal; white areas indicate sea surface heights between 14 and 32 centimeters (6 to 13 inches) above normal. In the western tropical Pacific, sea levels (red and white areas) are beginning to rise as strong trade winds are sweeping the warm El Nino waters westward.
Elsewhere, the influence of the 20- to 30-year larger than El Niño/La Niña pattern called the Pacific Decadal Oscillation continues to create warm, higher-than-normal sea-surface heights in the north Pacific that are connected in a warm horseshoe pattern with the western and southern Pacific.ÿ
Looking ahead, oceanographers will be carefully monitoring Pacific sea levels to see whether the tropical Pacific returns to normal or switches to La Nina conditions as it did in 1998, after the huge El Niño of 1997-1998.
Sea-surface heights are a measure of how much heat is stored in the ocean below. This heat influences both present weather and future planetary climate events.
Image courtesy NASA/JPL Ocean Surface Topography Science Team