北半球极涡指数对高原夏季降水的影响

The Response of Summer Rainfall in Tibet to Polar Vortex Index

利用奇异值分解方法(SVD)分析了夏季降水对极涡面积和极涡强度指数的响应,研究发现,冬季北半球极涡指数场与高原夏季降水场,在青海省大部分是明显的负相关区域,西藏大部分以正相关为主;春季北半球极涡指数场与西藏和青海夏季降水场为正相关。冬季12月极涡指数与高原夏季6月降水的相关,自高原东南部到西北部呈"+-+"分布;冬季1月极涡指数与高原夏季7月降水相关,南北呈"+-"分布,西藏为正相关,青海为负相关;冬季2月极涡指数与高原夏季8月降水,除柴达木盆地北侧、西藏西部为弱的负相关外,其余地区均为正相关。

Study the response of summer precipitation in Tibetan to polar vortex index, using singular spectrum analysis （SSA）. The result show, the positive conelation polar vortex index with summer precipitation in most area of Qingbai provinces, then negative all of Tibetan in the winter; the positive conelation polar vortex index with summer precipitation in Qinghai and Tibetan in the spring. Correlation Polar vortex index of December with summer precipitation in Tibetan of June display ＂ ＋ - ＋ ＂ from south - east to north - west of Qinghai - Xizang plateau ; Correlation Polar vortex index of Januai7 with summer precipitation in Tibetan of July display ＂ ＋ - ＂from south to north ; Conelation Polar vortex index of February with summer precipitation in Tibetan of August except north of Qaidam basin and west of Tibetan display negative correlation, then other area of Qingbai -Xizang plateau display positive correlation.