中国冬季大范围持续性低温事件低频特征及其与大气低频振荡的联系  

Low-Frequency Characteristics of Large-Scale Persistent Low Temperature Events in Winter in China and its Relation to Atmospheric Low-frequency Oscillation

作　　者：谭赢 李丽平[1] 施春华[1] 毛炜峄[2] 李一格 TAN Ying;LI Liping;SHI Chunhua;MAO Weiyi;LI Yige(Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/Key Laboratory of Meteorological Disaster(NUIST),Ministry of Education,Nanjing University of Information Science&Technology,Nanjing 210044,Jiangsu,China;Institute of Desert Meteorology,China Meteorological Administration,Urumqi 830002,Xinjiang,China;Xiyang County Meteorological Bureau,Xiyang 045300,Shanxi,China)

机构地区：[1]南京信息工程大学气象灾害预报预警与评估协同创新中心/气象灾害教育部重点实验室,江苏南京210044 [2]中国气象局乌鲁木齐沙漠气象研究所,新疆乌鲁木齐830002 [3]昔阳县气象局,山西昔阳045300

出　　处：《高原气象》2022年第6期1410-1424,共15页Plateau Meteorology

基　　金：国家重点研发计划项目(2018YFC1505602)。

摘　　要：利用1980-2017年国家气象信息中心提供的2481站逐日气温和NCEP/NCAR逐日再分析资料,对比研究了大气低频振荡对中国冬季三类(即:全国类、东北类和东部类)大范围持续性低温事件(以下简称事件)的影响差异。结果表明:20世纪80-90年代初和21世纪00年代后期以来事件偏多,冬季温度均具10~30天显著周期。通过对对流层大气环流场分析发现,在低层三类事件主要受低频西伯利亚高压(Siberian high,SH)影响,SH在全国类最强,东北类最弱;SH范围在全国类最大,南边界可达长江以南,在东北类和东部类中偏东。此外偏西的低频阿留申低压也是影响东北类事件的主要低频系统之一。在中层,全国类和东部类事件均有低频横槽转竖并和东亚大槽合并的过程,横槽在全国类中纬向尺度更大,东北类主要受东北冷涡度的影响。在高层,在全国类事件中温带急流整体持续偏弱,副热带急流整体持续偏强;东北类温带急流西强东弱,副热带急流西弱东强;东部类中温带急流整体持续偏弱,且偏弱程度大于全国类,副热带急流西强东弱。要分别关注低频500 hPa高度场上-12天(全国类)、-9天(东北类)和-10天(东部类)的西部预测信号,以及-12天(全国类)的东部信号。Based on the daily air temperature data from more than 2000 stations by the National Meteorological Information Center and NCEP/NCAR daily reanalysis data from 1980 to 2017,the effects of low-frequency oscillation on three types(nationwide,northeastern and eastern) of large-scale persistent low temperature events(short for events)in winter over China are compared and studied. The results show that there are more events since the 1980s to the early 1990s and the 2000s,and the winter temperature has a significant period of 10~30days. By analyzing the atmospheric circulation field,it is found that the low-frequency Siberian high(SH)is the main influence system of the three types of events in the lower level. The low-frequency Siberian high is the strongest in the national type events,and the weakest in the northeast type events. The range of the Siberian high is the largest in the national type events,with its southern boundary can reach the south of the Yangtze River,and it is tilted to east in both the northeast and east type events. In addition,the low-frequency Aleutian low(AL)to the west is also one of the main low-frequency systems affecting the northeast type events. In the middle troposphere,both the national and east type events have the process of the low-frequency transverse trough turning vertically and merging with the East Asian trough,and the transverse trough has a larger zonal scale in the national type events,while the northeast type events are mainly affected by the northeast cold vortex. In the upper troposphere,we can find that the temperate jet stream as a whole continued to be weak and the subtropical jet stream as a whole continued to be strong in the national type events. Temperate jet stream is strong in the west and weak in the east,while the subtropical jet stream is weak in the west and strong in the east in the northeast type events. The temperate jet stream in the eastern type events continue to be weak,but the degree of weakness is greater than that of the national type events,and the

关 键 词：持续性低温事件 中国冬季 大气低频振荡 延伸期预报 

分 类 号：P466[天文地球—大气科学及气象学]