春季格陵兰海冰变化及与北大西洋涛动和北极涛动的联系

采用长序列(1903—1994年)GISST海冰面积和海表温度(SST)资料、NCEP／NCAR再分析资料等，分析了春季格陵兰海冰面积年代际变化特征及其同北大西洋海气变化的关系。结果表明：春季格陵兰海冰面积变化的主要特征可由海冰变化的EOF第一主分量表示。春季海冰变化与前冬NAO／AO以及冬春1—4月份北大西洋墨西哥湾流区SST具有明显的反相变化趋势，且均具有准60a的周期变化特征。海洋向大气的热量输送(感热、潜热)受到海冰变化的显著影响(冰多输送少)。海冰作为大气的冷源，也明显影响地表净辐射的变化。进而，春季海冰变化可影响后期的大气环流变化：海冰面积偏大(偏小)，冰岛低压和阿留申低压偏弱(偏强)，夏季北非和亚洲大陆的SLP明显偏低(偏高)，两大陆夏季热低压加强(减弱)。

Interdecadal Variations of Spring Greenland Sea-ice Extent and Its Relationships with North Atlantic and Arctic Oscillations

The interdecadal variation of spring Greenland sea ice extent and its relationships with the North Atlantic and Arctic Oscillations are examined by using GISST sea ice extent and SST datasets along with NCEP/NCAR 40 year reanalysis.It is found that the spatial distribution and temporal variation of spring Greenland sea ice extent can be represented by its leading EOF mode.The variation of spring sea ice extent are evidently out of phase to the variations of NAO and AO in precedent winter as well as JFMA mean SSTA in North Atlantic warm current region.Aquasi-60 year period is detected in the variations of the four.As a cold source of the atmosphere,sea ice anomalous variation has significant impacts on the latent and sensible heat fluxe form theocean to the atmosphere as well as the surface net radiation.The larger sea ice extent decreases the surface heat transports to the atmosphere.Consequently,the anomalies of spring sea ice can impact the atmosphere in following seasons.When sea ice extent is larger(smaller),the Icelandics low and Aleutian low weaken(strengthen),and summer heat lows over North African and Asian continents intensify(weaken) accompanied by evident lower(higher) SLPs.