Changes in sea level, thermocline depth and
sea surface temperature (SST)
associated with El Niño.
The three images below represent the state of the Pacific Ocean along the equator during three different months in 1997 and 1998. The western Pacific (near Indonesia) is on the left and the eastern Pacific (off the coast of Peru) is on the right. These 3-D maps show sea level as bumps in the sea surface and sea temperature in color. Red is 30 degrees C and blue is 8 degrees C. Typically, higher sea level corresponds to warmer SST. The thermocline is the name for the sharp gradient in the ocean between the very cold deep water and the warmer water at the surface. It is measured as the 20 degrees C contour and is shown here as the border between the dark blue and the cyan colors.
The three dimensional relief map shows a sea level rise along the Equator in the eastern Pacific Ocean of up to 34 centimeters with the red colors indicating an associated change in sea surface temperature of up to 5.4 degrees C. The sea temperature below the surface illustrates how the thermocline is flattened out by El Niño.
Data from 1/1/97 to 3/10/98. The sea surface topography was measured by NASA's TOPEX satellite, sea surface temperature was derived from NOAA's AVHRR satellite sensor and sea temperature below the surface was measured by NOAA's network of TAO moored buoys.
Normal Conditions: January 1997
Images from NASA Goddard Space Flight Center