7B.2
Sensitivity of Tropical Tropospheric Temperature to Sea Surface Temperature Forcing
Hui Su, Univ. of California, Los Angeles, CA; and J. D. Neelin and J. E. Meyerson
During El Ni\~no, there are substantial tropospheric temperature anomalies across the entire tropical belt associated with the warming of sea surface temperature (SST) in the central and eastern Pacific. The Quasi-equilibrium Tropical Circulation Model (QTCM) forced with subregions of positive sea surface temperature (SST) anomalies is used to investigate the mechanisms for tropical tropospheric temperature anomalies during ENSO. Both observations and model simulations show that tropospheric temperature anomalies are wide-spread and strong precipitation anomalies are localized to positive SST forcing. The tropical-averaged tropospheric temperature response is approximately linear with tropical SST forcing. Nonlinearity in tropical-averaged tropospheric temperature response can be modest even when precipitation response is highly nonlinear. Subregions of warm SST anomalies contribute fairly evenly to tropospheric temperature anomalies, although regions over climatologically warm water have a slightly higher sensitivity.
Session 7B, Large-Scale Dynamics and Convection II (Parallel with Sessions 7C and 7D)
Tuesday, 30 April 2002, 4:00 PM-5:30 PM
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