Recorded presentation14.4
Observed Impact of Subtropical-Midlatitude South Atlantic SST Anomalies on the Atmospheric Circulation
Qigang Wu, Univ. of Oklahoma, Norman, OK
A lagged maximum covariance analysis (MCA) of monthly anomaly data from the NCEP–NCAR reanalysis during 1981-2007 suggests that the atmosphere over subtropical-midlatitude South Atlantic during the austral late winter and spring is significantly correlated to the underlying sea surface temperature (SST) anomalies (SSTA) up to at least 4 months earlier. Such SST impact on the atmosphere is independent from the remote forcing associated with the ENSO and tropical South Atlantic SSTA, and is confirmed by the regression analysis based on the SSTA centers of action. The MCA pattern of SST resembles the dominant mode of SST variability, which is itself driven by the persistent atmospheric forcing from austral summer to early winter. The monopole atmospheric signal is barotropic through the troposphere and hemispheric in extent. This implies predictability of the late winter and spring atmospheric circulation in the subtropical-midlatitude South Atlantic with a lead time of up to 4 months.
Session 14, Coupled ocean-atmosphere interactions and their contribution to climate variability on all time scales: Part 3
Thursday, 15 January 2009, 1:30 PM-3:00 PM, Room 128AB
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