热带太平洋与热带大西洋海表温度主模态的相互作用

根据英国Hadley气候中心的海表温度资料和美国NCEP/NCAR中心的大气资料,研究了热带太平洋与热带大西洋海表温度主模态的相互作用。热带太平洋的ENSO可以导致大西洋Nino模态或经向偶极子模态,这主要是通过热带海洋-大气相互作用,或大气的太平洋-北美遥相关过程实现的。大西洋Nino模态的暖(冷)位相会导致赤道中东太平洋的海表温度降低(升高)。这可能是通过两种途径完成的:一种可能是大西洋Nino使印度洋增暖(变冷),进而引起赤道中太平洋的东(西)风异常,通过海洋-大气相互作用正反馈机制能发展成为La Nina(El Nino),使赤道东太平洋海温降低(升高);另一种可能是大西洋Nino直接可以导致太平洋Walker环流增强(减弱),从而使赤道东太平洋海温降低(升高)。

THE INTERACTIONS BETWEEN DOMINATING MODES OF THE SEA SURFACE TEMPERATURE IN TROPICAL PACIFIC AND TROPICAL ATLANTIC

Based on the Sea Surface Temperature (SST) data of Hadley Centre and NCEP/NCAR atmospheric reanalysis, the interactions between the SST anomalies in Tropical Pacific and Tropical Atlantic are studied. The Pacific ENSO can give rise to Atlantic Ni?o Mode (ANM) or Atlantic Meridional Dipole Mode. This depends on whether ENSO influences the Atlantic through the tropical ocean-atmosphere interaction between both oceans or through the response of mid-latitude atmospheric circulation anomalies by Pacific-North America teleconnection mechanism. The warm (cold) ANM should lead to the cooling (warming) in the central and eastern Equatorial Pacific through two possible ways: The warm (cold) ANM should induce the Indian Ocean warming (cooling), which triggers easterly (westerly) wind anomalies in tropical Pacific and then the development of La Ni?a (El Ni?o) through ocean-atmosphere interaction positive feedback mechanism. In addition the warm (cold) ANM should directly strengthen (weaken) the Walker Circulation in Pacific and decrease (increase) SST anomalies in eastern Equatorial Pacific.