松花江流域冬季降雪的年际变化与西北太平洋海温的关系  

Interannual Variation in Snowfall over Songhua River Basin and Its Relationship with West North Pacific Sea Surface Temperature Anomalies during Boreal Winter

作　　者：李永生[1,2] 陈晨 娄德君 包立红 张丽娟 LI Yongsheng;CHEN Chen;LOU Dejun;BAO Lihong;ZHANG Lijuan(Heilongjiang Climate Center,Harbin 150030,Heilongjiang,China;Key Opening Laboratory for Northeast China Cold Vortex Research,Shenyang 110166,Liaoning,China;Qiqihar Meteorological Bureau,Qiqihar 161006,Heilongjiang,China;Heilongjiang Province Key Laboratory of Geographical Environment Monitoring and Spatial Information Servicein Cold Regions,Harbin Normal University,Harbin 150025,Heilongjiang,China)

机构地区：[1]黑龙江省气候中心,黑龙江哈尔滨150030 [2]东北冷涡研究重点开放实验室,辽宁沈阳110016 [3]齐齐哈尔市气象局,黑龙江齐齐哈尔161006 [4]哈尔滨师范大学寒区环监测与信息服务重点实验室,黑龙江哈尔滨150025

出　　处：《高原气象》2023年第1期128-138,共11页Plateau Meteorology

基　　金：国家自然科学基金项目(41771067);黑龙江省自然基金重点项目(ZD2020D002);中国气象局沈阳大气环境研究所联合开放基金(2021SYIAEKFMS10)。

摘　　要：利用松花江流域(Songhua River Basin,SRB)103站降水资料、NCEP/NCAR再分析资料以及NOAA海温等资料,运用多种统计方法,分析了1979-2019年松花江流域冬季降雪的年际变化特征及其与西北太平洋地区海温异常的联系。研究表明,松花江流域冬季降雪主要受到其年际变率的调控,且年际降雪异常EOF分解的第一模态表现为流域一致型变化(方差贡献率为55.3%)。当松花江流域冬季年际降雪偏多(偏少)时,鄂霍次克海到阿留申地区出现位势高度正异常(负异常),其南部中低纬地区位势高度为负异常(正异常)。进一步分析表明,冬季西北太平洋地区偶极子型海温异常对同期松花江流域年际降雪有重要影响。当西北太平洋海温偶极子为正位相时(日本海地区海温正异常,菲律宾群岛以东地区海温负异常),引起西北太平洋中高纬地区对流层中层出现位势高度正异常,低层为异常反气旋式环流,中低纬地区对流层中层出现位势高度负异常,低层为异常气旋式环流。在此环流背景下,北太平洋到松花江流域被异常东南风控制,有利于阿留申以南海域以及我国东部近海地区的水汽输送至松花江流域并辐合上升,导致该流域冬季年际降雪增加;反之亦然。Based on the 103 stations precipitation over Songhua River Basin(SRB),the reanalysis data of NCEP/NCAR,the sea surface temperature(SST)from NOAA,the interannual variation in snowfall over SRB and its relationship with west north Pacific SST anomalies(SSTA)during boreal winter for 1979-2019 are investigated by using statistical analysis methods.The results show that the snowfall over SRB during winter is mainly characterized by its interannual variation(explains 83.3%of total variation),and the first leading EOF mode of interannual snowfall anomalies of SRB during winter is dominated by a homogeneous structure(explains 55.3%of total variance)indicating significant covariability over the SRB.The atmospheric circulation associated with the interannual SRB winter snowfall suggests that the above-normal(below-normal)snowfall is induced by positive(negative)geopotential height anomalies over the region from Okhotsk to Aleutian island and negative(positive)geopotential height anomalies over the mid-low latitude to the south of Okhotsk Sea.Further analyses indicate that the dipole structure of SSTA over WNP during winter has a profound impact on the simultaneous interannual snowfall over SRB.The positive WNP SSTA dipole(positive and negative SSTA over Japanese Sea and east to the Philippines Islands,respectively)can induce positive geopotential height anomalies in the upper troposphere and anomalous anticyclone in the lower troposphere in the mid-high latitudes over WNP,as well as the negative geopotential height anomalies in the upper troposphere and anomalous cyclone in the lower troposphere in the mid-low latitudes.The region from north Pacific to the SRB is covered by anomalous southeasterly winds during winter under the influence of these anomalous atmospheric circulation.As a result,the moisture from the sea to the south of Aleutian and the sea to the east of China are transported to the SRB accompanied by anomalous convergent flow in situ,which are favorable for the increasing snowfall over SRB;and vice versa.

关 键 词：松花江流域 冬季降雪 大气环流 海温异常 

分 类 号：P461.2[天文地球—大气科学及气象学]