Air-sea feedbacks in the western Pacific using a coupled single-column model

The interaction between the tropical atmosphere and the warm pool consists of intense exchanges of heat, momentum, and water. The core of this interaction is the sea surface temperature. The ocean responds to the atmospheric forcing by changes in SST while the atmosphere receives the feedback from the ocean on changes in fluxes based on the corresponding sea surface temperature. This coupling of the atmosphere-ocean system occurs over several time scales. However, it is difficult to separate cause and effect and to isolate the feedbacks between the atmosphere and ocean using observational data only. Model experiments provide another approach to be used to quantify feedback mechanisms, assuming the models are able to accurately simulate the relevant climate processes and sensitivities. In this study, both data and a coupled model are used to test atmosphere/ocean feedback processes on time scales ranging from hours to months. This coupled model consists of a 1-D ocean mixed layer model (Kantha and Clayson 1994) and the single-column version of the NCAR Community Climate Model. Some examples of case studies during the TOGA COARE IOP will be shown, as will results of a statistical time series analysis that has been used to analyze the cause-effect mechanisms between the coupled system. The results of the time series analysis of the data is then used for comparisons to both the stand-alone and coupled atmosphere and ocean models.