Spatial Correlation Between Regional Long-Term Changes in sea Level and sea Surface Temperature

Abstract

Long-term sea level change is important for a variety of environmental and socio-economic reasons, especially for the large portion of the world’s population who lives in coastal zones. Satellite altimetry now offers a unique opportunity for improving our knowledge about global and regional sea level change. TOPEX/POSEIDON (T/P) sea level observations and Reynolds AVHRR sea surface temperature observations over the most recent 8 years have qualitatively been used to study regional correlations between long-term changes in sea level and sea surface temperature. Long-term is here taken to be linear signals in the 8-year time period. Consistent increases in both sea level and sea surface temperatures are found in most parts of the Atlantic Ocean over this period. In the Indian Ocean and particularly the Pacific Ocean, the trends in both sea level and temperature are still dominated by the large changes associated with the El Nino Southern Oscillation (ENSO). Sea level changes over the most recent 8 years detected by T/P sea level observations are correlated with changes in the Reynolds AVHRR sea surface temperature observations with a global averaged correlation of 0.62. On regional scales this number becomes higher. Specifically, in the tropical part of the Pacific and Atlantic Ocean where the correlation computed over 20° latitude bands increases to 0.89.