利用欧洲中心ERA-I和NCEP CFSR再分析资料、 NCEP CFSv2回报和预报资料, 分析了20世纪80年代以来北半球平流层极涡边界的年代际变化特征, 评估了CFSv2系统对北半球极涡边界的模拟能力。结果表明: 1980 -2017年, 从整体趋势来讲, 冬季北半球极涡在北美区域回缩北退, 在欧亚区域扩张南进; 秋季北半球极涡在北美地区呈扩张趋势, 在欧洲地区呈回缩趋势, 在亚洲地区从20世纪80年代到21世纪00年代是明显扩张的趋势, 10年代又为明显回缩趋势。在冬季, 北美区域极涡回缩主要在20世纪90年代, 欧洲区域极涡的南扩主要在21世纪00年代, 亚洲区域极涡的南扩主要在20世纪90年代。在秋季, 北美地区极涡边界的南扩主要在20世纪90年代, 欧亚区域极涡的回缩发生在21世纪10年代, 西欧地区的回缩最明显。CFSv2模拟的冬季极涡边界和面积的20世纪80年代至21世纪10年代的总体变化趋势与ERA-I资料一致, CFSv2尤其对21世纪10年代北美和亚洲极涡都扩张的趋势模拟的很清楚, 但模拟的北美区域极涡边界呈回缩趋势的范围偏东, 在10年代明显偏南, 模拟的欧洲区域极涡边界20世纪90年代偏北, 21世纪10年代偏南, 没有模拟出亚洲区域极涡边界在20世纪90年代和21世纪00年代的扩张。CFSv2对秋季极涡边界和面积的模拟水平比冬季的低, 对极涡边界和面积变化总体趋势的模拟较差, CFSv2模拟的北美地区极涡边界在20世纪90年代和21世纪10年代与ERA-I的一致, 但20世纪90年代扩张的区域偏大, 模拟的欧洲区域极涡边界的回缩主要在21世纪00年代, 而ERA-I的在10年代, 模拟的亚洲区域极涡边界在20世纪90年代与ERA-I的一致, 但在21世纪00年代和10年代与ERA-I的误差较大。
By using the ERA-I, the NECP CFSR reanalysis data and the CFSv2 of NECP reforecasts and forecasts data, the inter-decadal variations of the stratospheric polar vortex boundary in the northern hemisphere since the 1980s are analyzed, the ability of the CFSv2 to simulate the polar vortex boundary is evaluated.Results show that, from 1980 to 2017, the Arctic polar vortex retreats northward in North American and expands southward in Eurasia in winter, but the polar vortex expands in North America and retreats in Europe in autumn.The polar vortex expands obviously from the 1980s to the 2000s and retreats in the 2010s in Asia.In winter, the retraction of the polar vortex occurs mainly in the 1990s in North America, but the expansion of the polar vortex occurs mainly in the 2000s in Europe and in the 1990s in Asia.In autumn, the southern expansion of the polar vortex boundary in North America is mainly in the 1990s, the retraction of polar vortexes in Eurasia occurs in the 2010s, and the retraction in Western Europe is the most obvious.The overall trend of the winter polar vortex boundary and area simulated by CFSv2 is consistent with the ERA-I data in the 1980s -2010s, especially for the trend of expansion in North America and Asia in the 2010s.However, the boundary of the polar vortex simulated by CFSv2 is more to the east, and more to the south in the 2010s in North America.The boundary of the polar vortex simulated by CFSv2 is north in the 1990s and south in the 2010s in Europe.The expansions of Asia polar vortex boundary in the 1990s and 2000s in Asia cannot be simulated.In autumn, the simulation abilities of CFSv2 on the boundary positions and areas are poor than that in the winter, the simulations on the overall trend of polar vortex boundary and area variation are poor.The North American polar vortex boundaries simulated by CFSv2 are consistent with the ones of the ERA-I data in 1990s -2010s, but the range of expansion is larger in the 1990s.The retraction of the polar vortex boundary is mainly in the 2000s from CFSv2 while in the 2010s from ERA-I in Europe.The polar vortex boundary simulated by CFSv2 is consistent in the 1990s but exists more errors in the 2000s -2010s with the one of the ERA-I data in Asia.
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