| The role of TRMM daily precipitation on the interannualvariability of the Indian Ocean climate are examined with data(Reynolds SST, TOPEX sea level, AVHRR SST, QuikSCATwind stress, TRMM daily and ARKIN monthly precipitation) and a nonlinearreduced-gravity thermodynamic model. Two experiments are performed.In the first experiment (Run ARKIN), the ocean is forced with QuikSCATdaily winds and ARKIN monthly precipitation. In the second experiment(Run TRMM), wind remains unchanged, but rainfall is prescribed to the TRMMdaily precipitation calibrated onto ARKIN monthly values. Interestingly,differences of SST between the two experiments are not large where TRMM andARKIN differ most. Since climatological heat fluxes are used to force themodel, changes of temperature are solely due to oceanic processes. Themaximum SST difference is as large as 2 degree Celsius in the southwesterntropical Indian Ocean. This location corresponds to the shallowest thermoclinein the Indian Ocean on annual average, implying a strong ocean feedbackonto the atmosphere. Thus, the impact of high-frequency rainfall on SSTis potentially important for the coupled Indian Ocean-Atmosphere processesthat are responsible for the climate changes. |
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