云南省1981—2013年降雪过程气候特征及环流型分析  

The climatic characteristics of snowfall processes and the circulation patterns of Yunnan from 1981 to 2013

作　　者：陶云[1] 陈艳[1] 段长春[1] 任菊章[1] 何华[2] TAO Yun1 CHEN Yan1, DUAN Chang-chun1 , REN Ju-zhang1 , HE Hua2(1. Meteorological Institute of Yunnan Province, Kunming 650034, China ; 2.Yunnan Meteorological Observatory, Kunming 650034, China)

机构地区：[1]云南省气象科学研究所,云南昆明650034 [2]云南省气象台,云南昆明650034

出　　处：《云南大学学报（自然科学版）》2018年第6期1171-1180,共10页Journal of Yunnan University(Natural Sciences Edition)

基　　金：国家自然科学基金(41565002;41365007;41665004);NSFC-云南联合基金重点项目(U1502233)

摘　　要：利用云南124个气象观测站1981—2013年逐日天气资料和NCEP/NCAR 2.5°×2.5°再分析资料,分析了云南降雪天气过程的气候特征、大气环流以及物理场特征.结果表明:(1)云南降雪天气过程总变化趋势呈显著减少,平均减少0.6次/10 a,通过了95%的显著性检验.昆明降雪最早出现在11月,最晚出现在3月,集中于12月和次年1月.最长连续降雪时间是5 d,最短为1 d,大部分为2~3 d.(2)云南降雪过程受中高纬度和低纬度系统的共同影响,并与地面及近地面上的系统也密不可分.从500 h Pa环流系统看,北脊南槽型是造成云南省冬春季雨雪天气最主要的环流型.南支槽是产生云南大范围雨雪天气的重要系统之一;近地面的切变线天气系统也是云南省冬春季发生大范围雨雪天气的重要系统;地面冷空气的南下影响是云南省大范围雨雪灾害天气发生的必要条件.(3)云南降雪天气过程主要分北脊南槽型、北横槽有南支槽型和北横槽无南支槽型.(4)3种降雪型在水汽输送、热力及动力条件存在一定异同.3类降雪过程均有充沛的水汽从云南西侧和南侧输送至云南境内,为降雪过程提供有利的水汽条件.不同之处则是有南支槽的降雪过程水汽来自孟加拉湾洋面,而无南支槽的降雪过程水汽来自较远的阿拉伯海地区.3类降雪过程云南境内均处于高温高湿的热力条件下,在冷空气入侵的抬升作用下易产生强降雪(雨).横槽型冷空气强度较北脊型强,影响云南的冷空气位置更偏南偏西.3类降雪过程的上升运动在强度和位置上有所不同,也决定了强降雪(雨)区域的大小和强度.The climatic characteristics, circulation patterns and physical field features are analyzed, based on the daily weather phenomenon data （1981--2013） of 124 stations of Yunnan Province and NCEP/NCAR（2.5°× 2.5°） re-analytical data.The results show： Firstly ,in over 30 years （1981--2013） , the snowfall showed an obvi- ous declining trend in Yunnan.The declining rate was 0.6 time every 10 years,which passed 95% of significant tests.The snow fall in Kunming mainly appeared in December and January, with the earliest in November, and the latest in March.The continual snowfall mostly lasted 2 to3 days, the longest lasting 5 days, and the shortest,just 1 day.Secondly, the snowfall processes in Yunnan are affected by the weather systems of the high latitudes as well as the low latitudes and they are also influenced by the ground and near-surface weather systems.Seen from the 500 hPa circulation system,the north-ridge-and-south-trough pattern is the most important that causes rainfall and snowfall in winter and spring in Yunnan Province. The south branch trough is one of the important weather systems leading to the large-scale rain and snow in Yunnan.The shear line weather system of near-surface is also important in causing the large-scale rain and snow in winter and spring in Yunnan.It is the southward influence of the cold air that leads to the large-scale disasters of rain and snow in Yunnan Province. Thirdly , Yunnan ＂s snowfall processes are mainly divided into three categories ： the pattern of the north ridge and south trough, of the north transversal trough with south trough, and of the north transversal trough without south trough. Fourthly, there are some similarities and differences between the three snowfall patterns in water vapor transmission, and thermal and dynamic conditions.All three snowfall patterns carry abundant water vapor to Yunnan from the west and south and provide favorable vapor conditions for snowfall. The difference is that the water vapor of snowfall processes with the sout

关 键 词：云南省 降雪过程 气候特征 环流型 物理量特征 

分 类 号：P44[天文地球—大气科学及气象学]