遵义市1960-2020年降雪特征分析

Analysis on the space-time distribution of snowfall in Zunyi from 1960 to 2020

利用1960-2020年共61 a遵义市12个国家站点的地面观测日资料,采用一般统计学方法分析遵义市降雪时空分布特征,并利用NCEP(美国国家环境预报中心)再分析资料分析了遵义市3次暴雪个例的环流特征。结果表明:遵义市1960-2020年降雪年变化呈波动变化特征,整体呈下降趋势。月平均降雪日数呈现单峰特征,1月份达到峰值。各站点月降雪日数1月和2月明显多于其他月份。空间上,西北方向的习水到东部的凤冈一线降雪日数较多,大部分站点降雪日数分布与站点海拔正相关。另外,遵义市2000年以来的暴雪个例都是暖湿气流在冷垫上爬升,造成暴雪天气。

Daily data of ground observation from 12 stations in Zunyi during the period of 1960-2020 was used to assess the space-time distribution characteristics of snowfall by general statistical methods,and the data from NCEP was further used to analyze the circulation characteristics of three blizzard cases in Zunyi.Results indicated that number of annual snowfalls was fluctuated and showed a decreased pattern from 1960 to 2020.The average snowfall days per month was shown in an unimodal feature and the peak was present in January.Furthermore,the number of average snowfall days per month at each site in January and February was significantly higher than in other months.In terms of the spatial characteristics,there were more snow days on the line from Xishui in the northwest to Fenggang in the east than in other areas of Zunyi,and the distribution of snowfall days was positively correlated with the elevation of the stations located.In addition,there were points in common about the circulation patterns of each layer of blizzard cases since 2000 that warm and humid air climbs over the cold pad,creating blizzard conditions.