The Role of Sea Surface Temperature in Large-Scale Air-Sea Interaction

Abstract

Data from the 1972?73 El Niño event are used to study relationships between sea surface temperature (SST), surface wind, surface heat fluxes and rainfall in the tropical Pacific cast of the dateline. It is found that the maximum in SST anomaly is not correlated spatially or temporally in any consistent manner with the sum of latent and sensible heat fluxes (QE + QS) or rainfall as estimated from highly reflective cloud. Varying anomalies in wind speed and sea-air temperature and humidity differences all influence the QE + QS anomaly in ways which may be unrelated to the SST anomaly. Factors influencing SST, namely zonal wind stress and net surface heating, are found to vary with longitude. The position of the rainfall maximum and the time variation of rainfall in the near-equatorial convergence zone are more closely related to moisture convergence than to SST. Implications to modeling efforts which equate SST anomalies with diabatic heating anomalies are discussed.