Role of specific humidity anomalies in Caribbean SST response to ENSO

Remote influences of El Nino-Southern Oscillation (ENSO) on tropical Atlantic sea surface temperature (SST) are examined using reanalysis and in-situ observational datasets. During both the warm and cold events of ENSO, latent heat flux anomalies are the major mechanism for SST anomalies over the Caribbean Sea. Results from a linear decomposition of the latent heat flux anomalies indicate that the anomalous air-sea difference in specific humidity (Delta q') is the dominant term in January, one month after the ENSO's mature phase. Since anomalies of SST and saturation specific humidity at the sea surface are still small in January, Delta q' is due mostly to changes in specific humidity in the lower atmosphere. Changes in surface air humidity and temperature, and their relationship to temperature variability in the upper troposphere during ENSO warm events are discussed.