The extratropical sensitivity to the meridional extent of tropical ENSO forcing

摘要: The extratropical response to tropical remote forcing has been examined with so-called ocean-global atmosphere experiments, which use prescribed sea surface temperature (SST) in the Pacific and a slab mixed-layer ocean model elsewhere. In this study we have revisited experimental design found that is quite sensitive meridional extent of SST domain. Even case annual cycle only (i.e., no ENSO), differences regions lead different atmospheric motions adjacent extratropics. When includes ENSO, sensitivity domain more prominent, especially during La Nina events. Nina, warmer than simulated northern subtropics, continue 30°N. This broad accompany enhanced circulation directly connects tropics extratropics within basin. Moreover, Rossby wave excitation also increases, so effect region difference felt beyond On other hand, ENSO anomalie experiment composite minus control cycle, both same domain) stronger experiment. However, anomaly from own similar regardless region, commonly mimics Northern Hemisphere El Nino nature boreal winter season.