On decadal-scale ocean-atmosphere interactions in the extended ECHAM1/LSG climate simulation

摘要: The last 810 years of a control integration with the ECHAM1/LSG coupled model are used to clarify nature ocean-atmosphere interactions at low frequencies in North Atlantic and Pacific. To first approximation, atmosphere acts as white noise forcing ocean responds passive integrator. sea surface temperature (SST) variability primarily results from short time scale fluctuations heat exchanges Ekman currents, former also damp SST anomalies after they generated. thermocline is driven by pumping. Because heat, momentum, vorticity fluxes correlated space time, directly linked that interior. modulated wind-driven geostrophic fluctuations, resulting persistent correlation changes slight low-frequency redness spectra. main dynamics similar two oceans, although Pacific more strongly influenced advection oceanic scales larger. A maximum covariance analysis based on singular value decomposition lead lag conditions indicates some modes atmospheric oceans sustained very weak positive feedback between atmosphere, SST, strength subtropical subpolar gyres. In addition, pressure mode has small quasi-oscillatory component 6-year period, advective resonance occurs for around 10-year both periods being singled out multichannel spectrum analysis. coupling however much too redden tropospheric spectra or create anything than tiny spectral peaks, so dominated sectors one-way interactions.