| Various types of air-sea interactions are studied based on the generalproperties of cross covariance function and the well-defined shapes ofthese functions obtained from conceptual models. The analysis isapplied to sea surface temperature and surface fluxes obtained from along integration with the coupled ECHAM3/LSG model. The resultssuggest that the atmosphere plays a dominant role in generating thecoupled variability. Covariances between SST and wind stress in theextratropics are close to zero when SST leads, suggesting that SSTanomalies, once being generated, do not feed back to the atmosphere.The interactions between SST and tropical wind stress involve varioustypes of feedbacks. For heat flux, the antisymmetric shape of crosscovariance functions indicates that heat flux anomalies generate SSTvariations and the interaction tends to reverse the sign of theearlier SST anomalies. The atmosphere plays also an important role ingenerating coupled variations of SST and evaporation, and of SST andextratropical precipitation. The most dominant role of the ocean isfound in the tropics. The results can be used to verify simpleatmospheric models, which are used in ocean-only modellingstudies. Cross covariance functions found in such simple coupledmodels should be similar to those found in a fully coupledatmosphere-ocean GCM, if the simple models produce the sameinteractions found in fully coupled GCMs. |
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