全球变暖停滞背景下北半球风暴路径的年代际变化特征  

Interdecadal Shift of the Northern Hemisphere Storm Track under Global Warming Hiatus

作　　者：王刚[1] 黄菲[1,2] 王宏[1] 樊婷婷[1] 

机构地区：[1]中国海洋大学物理海洋教育部重点实验室和青岛海洋科学与技术国家实验室,山东青岛 [2]宁波大学宁波市非线性海洋和大气灾害系统协同创新中心,浙江宁波

出　　处：《气候变化研究快报》2017年第3期186-194,共9页Climate Change Research Letters

基　　金：国家重大科学研究计划项目(2015CB953904);国家自然科学基金项目(41575067)资助。

摘　　要：本文基于1979-2014年欧洲中期天气预报中心ERA-Interim的逐日再分析资料,用300 hPa位势高度场天气尺度扰动方差代表风暴路径,分析了北半球风暴路径的时空变化特征。结果表明,北半球风暴路径的强度和位置变化在1998年前后存在显著的年代际差异,且北太平洋风暴路径(PST)和大西洋风暴路径(AST)表现不同。在1998年后全球变暖停滞阶段PST出现“深冬抑制”现象加强的特征,且风暴轴位置向极移动,AST则出现最大强度从晚冬(2~3月)向深秋(10~11月)提前的变化趋势,风暴轴位置向南移动。这些特征均在风暴路径S-EOF的第一主模态时空特征中得以体现,特别是秋冬季节PST和AST“跷跷板”式的反位相年代际变化,可能与波–流相互作用的年代际差异有关,仍需要更深入的物理机制分析。Based on the ERA-Interim daily reanalysis data (1979-2014) from the European Center for Medium range Weather Forecasting (ECMWF), storm track is defined as monthly mean variance of geopotential height at 300 hPa with harmony filtering from 2 to 7 days. Temporal and spatial variations of the storm track over northern hemisphere are analyzed. Results indicate that the intensity and location of storm track have a remarkable interdecadal shift around 1998 and an opposite behavior for the Pacific storm track (PST) and the Atlantic storm track (AST). After 1998 when global warming hiatus period began, the “midwinter suppression” phenomenon of PST appears frequently and the PST shifts polar ward. Meanwhile, the AST maximum intensity occurs in October-November early than in February-March and the AST moves toward equator. These “seesaw” characteristics of PST and AST show clearly in the leading mode by a Season-reliant Empirical Orthogonal Function (S-EOF) analysis, especially in cold season. The storm track’s interdecadal shift may relate to the variability of mean flow-wave interaction, which is yet to be investigated.

关 键 词：风暴轴 年代际变化 太平洋 大西洋 S-EOF 

分 类 号：P4[天文地球—大气科学及气象学]