The ENSO footprint in monthly satellite evaporation over the global ocean during 1993–2007

Abstract

The spatial pattern of latent heat flux (LHF) variability associated with El Niño-Southern Oscillation (ENSO) is extracted using 15 years (1993–2007) of monthly satellite-derived LHF over the global ocean. This ENSO LHF footprint agrees well with the El Niño evaporation pattern reported previously with a 3-year (1996–1998) weekly version of this data set. LHF anomalies over the eastern tropical Pacific are positively correlated with sea surface temperature (SST) anomalies suggesting a damping effect on ENSO. Positive correlations with ENSO are also observed over the eastern mid-latitude North Pacific, western and central mid-latitude South Pacific and the equatorial Indian Ocean. Negative correlations are observed elsewhere. It is also shown that the LHF footprints of both phases of ENSO (El Niño and La Niña) present very similar spatial structure. As expected, the surface wind pattern associated with El Niño (La Niña) shows convergence (divergence) over the central and eastern tropical Pacific and divergence (convergence) around the western tropical Pacific.