Climate Change of Arctic Atmospheric Circulation in Last 30 Years and Its Effect on Strong Cold Events in China
Climate Change of Arctic Atmospheric Circulation in Last 30 Years and Its Effect on Strong Cold Events in China
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发表时间：
2006
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通讯作者：
Li Feng;Jiao Mei-yan;Din Yi-hui;J. Rong-hua
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作者：
Li Feng;Jiao Mei-yan;Din Yi-hui;J. Rong-hua
利用1971-2000年NCEP再分析资料和中央气象台提供的冷空气爆发过程资料，分析了1971-2000年北极大气环流特征的气候变化及其对我国强冷事件的影响，结果表明：1971-2000年冬半年，北极气温变化显著，1980年代中期以前，极涡范围偏大，后期有减小的趋势，极涡强度发生了相反的变化，同时，中高纬环流由低指数状态向另一种状态调整，趋向纬向型，冬季东亚大槽东移约1 °和2.2 °左右，西伯利亚高压（SH）也相应变化，70年代较弱，轨道较小，80年代和90年代增强并扩张，强度基本保持不变，但南边缘比80年代偏北1~2 °，结果表明，近30年来强冷事件发生的年代尺度变化主要表现为：70年代强冷事件发生频次多，主要来源于北欧，80年代强冷事件发生频次明显减少，主要来源于Novaja岛以东的西北路径，气温距平异常最大，极冷事件最强，1990年代虽然冷事件频次增加，强冷变化的特征雅阁极端事件与气候变化的关系，可能是地球仪变暖的结果和反映。
Based on the NCEP reanalysis data and the cold air outburst processes in each year provided by Central Meteorological Observatory(CMO) in 1971-2000,the climate changes of Arctic atmospheric circulation feature and its effect on strong cold events in China are studied.Results show that atmospheric temperature markedly change during the winter-half-year of 1971-2000,it reflects the polar vorticity(PV) shifting.Extent of PV is larger than normal prior to mid of 1980′s,it trends to reduce later and PV intensity change adversely.Synchronously,the circulation of mid-high latitude band adjust from low index state to another,trend to zonal pattern,East-Asian trough shift to east about 1 degree and 2.2 degree special in winter,Siberian high(SH) varies correspondingly,it is weaker and small orbit in 1970′s,it get stronger and expand in 1980′s and in 1990′s.SH keeps similar intensity but its south edge reduce 1~2 dgree northward than 1980′s,its scope reduce 5%.The findings indicate that the changes result in a decade-scale variation of strong cold event in past 30 years.The cold occur frequently in 1970′s,mainly root from North Europe.The frequency reduces evidently in 1980′s,root mostly from east of Novaja island by north-west route,departure of temperature is most abnormal and extremecold event is most strong.1990′s is the weakest decade though the cold event frequencyincrease,which is related closely with warming and high background air temperature.The features of strong cold change accord with relationship between extreme event and climate change,according it maybe result and reflect of the globe warming.