In three parallel experiments, an atmospheric general circulation model has been subjected to observed, monthly varying sea surface temperature (SSI) conditions in each of the following domains: near-global ocean (GOGA run), tropical Pacific (TOGA run), and midlatitude North Pacific (MOGA run). Four independent realizations were obtained for the model response to the sequence of SST anomalies during the 1946–88 period in each of the above regions. The principal modes of coupling between the imposed SST forcing and the simulated Northern Hemisphere wintertime 5 1 5-mb height field in various experiments have been identified using a singular value decomposition (SVD) procedure. The leading SVD mode for the GOGA experiment is Qualitatively similar to that based on observational data, although the amplitudes of the simulated height anomalies are notably lower than the observed value. The SST pattern of this mode resembles that associated with El Niño events. The accompanying 5 1 5-mb height anomaly i... Abstract In three parallel experiments, an atmospheric general circulation model has been subjected to observed, monthly varying sea surface temperature (SSI) conditions in each of the following domains: near-global ocean (GOGA run), tropical Pacific (TOGA run), and midlatitude North Pacific (MOGA run). Four independent realizations were obtained for the model response to the sequence of SST anomalies during the 1946–88 period in each of the above regions. The principal modes of coupling between the imposed SST forcing and the simulated Northern Hemisphere wintertime 5 1 5-mb height field in various experiments have been identified using a singular value decomposition (SVD) procedure. The leading SVD mode for the GOGA experiment is Qualitatively similar to that based on observational data, although the amplitudes of the simulated height anomalies are notably lower than the observed value. The SST pattern of this mode resembles that associated with El Niño events. The accompanying 5 1 5-mb height anomaly i...