青藏高原达索普冰川浅孔冰芯中δ^(18)O值对大尺度海-气相互作用的响应

Response of Magnitude of δ18O in Shallow Ice Core of Dasuopu Glacierin the Tibetan Plateau to Large Scale Sea-Air Interaction

青藏高原达索普冰川浅孔冰芯中δ１８Ｏ值与大尺度海表面温度（ＳＳＴ）之间存在显著的相关关系．显著相关区主要分布在海洋的洋流区，不同海区ＳＳＴ通过对大气环流的作用影响达索普冰川的降水和水汽来源．当大气环流呈现出有利于海洋水汽向青藏高原南部冰川输送的形势时，冰芯中δ１８Ｏ值减小．当大气环流呈现出不利于海洋水汽却有利于内陆水汽向青藏高原南部冰川输送的形势时，冰芯中１８Ｏ值增大相关分析表明，在诸多影响 １８Ｏ值的海温因子和环流因子中，北太平洋海流ＡＳ区平均ＳＳＴ，南海副高北界位置对达索普冰川隆冬时的１８Ｏ值有重要影响作用；北太平洋海流Ｂ区平均ＳＳＴ，北半球极涡中心位置和太平洋极涡强度对达索普冰川盛夏时的１８Ｏ值有重要影响作用．这些因子的变化制约着冰芯中１８Ｏ值的大小，其影响都具有先兆性．

There is a marked correlation betweenδ18O in shallow ice core in Dasuopu Glacier of theTibetan Plateau and large scale sea surface temperature (SST). The marked correlated regions are mainlydistributed in the ocean currents of the Oceans. TheSST in different sea regions influences precipitationand vapor origin of the Dasuopu Glacier by way of itsaction on atmospheric circulation. When the atmospheric circulation appears the situation favoring tothe transportation of oceanic vapor towards the glaciers in the southern Tibetan Plateau, δ18O in the icecore decreases, on the contrary, when the situation infavoring to that but favoring to the transportation ofinland vapor towards the glaciers, δ18O in the ice coreincreases. Among various SST and circulation factors influencing δ18O in the ice core, the mean SST inRegion A5 of the North Pacific Drift and the positionof the north boundary of subtropical high in theSouth China Ocean have an important impact on theδ18O in the Dasuopu Glacier in the midwinter; themean SST in Region B of the North Pacific Drift, thecenter position of the arctic eddy over the northernhemisphere and the strength of the polar vortex overthe Pacific have an important impact on theδ18O inthe Dasuopu Glacier in the midsummer. The variation of these factors governs the magnitude of 618O inthe ice core, with a precursory effect.