Multiyear satellite observations of the atmospheric response to Atlantic tropical instability waves

Abstract

High‐resolution satellite measurements from the Tropical Rainfall Measuring Mission (TRMM), Quick Scatterometer (QuikSCAT), and Special Sensor Microwave Imager (SSM/I) are used to study the variability of sea surface temperature (SST), surface wind velocity, water vapor, cloud liquid water, and precipitation associated with westward moving tropical instability waves (TIWs) in the Atlantic Ocean from 1998 to 2005. Coherent ocean‐atmosphere patterns are shown during these 8 years. Southeasterly trades strengthen and water vapor increases over warm SST anomalies associated with TIWs. The opposite is true over cold TIW SST anomalies. The cloud liquid water and rain response to the SSTs follows a similar pattern, appearing generally downstream of SST anomalies in the central tropical Atlantic. The atmospheric response to the TIW SST anomalies extends north of the TIW active region, suggesting a remote response to the TIWs. The atmospheric response to the Atlantic TIWs also exhibits interannual variations. In 1999, owing to the southward movement of the Atlantic Intertropical Convergence Zone (ITCZ), the rainfall response to the TIW SST anomalies is much larger than in other years. When the Atlantic ITCZ moves south, it is more susceptible to TIW influence.