湖南春播育秧期不同低温阴雨分布型的环流特征

发布时间：2018-10-30 13:47

【摘要】：利用1961—2013年湖南80个台站的逐日降水、平均气温、日照资料和NECP/NCAR再分析资料、海温资料,分析了近53年湖南省播种育秧期低温阴雨日数的主要分布类型与同期大气环流背景场及前冬海温分布特征。结果表明:(1)湖南省低温阴雨日数空间分布主要类型为全省一致型和南北相异型。(2)当欧亚大陆中高纬度受东亚大槽的影响,加上低层冷暖空气汇合和较好的湿度条件,有利于发生偏多型低温阴雨;相反,当欧亚大陆中高纬度受高压控制,加上低层中东部整体受异常北风和负相对湿度的影响,则易发生偏少型低温阴雨。当湖南北部受低槽的影响,且为相对湿度大值区时,易发生北多南少型低温阴雨;而当湖南南部受低槽和地形影响出现南岭静止锋,南部为相对湿度大值区时,则易发生北少南多型低温阴雨。(3)低温阴雨偏多(少)年前冬赤道中东太平洋以及阿拉斯加湾海温偏暖(冷),西北太平洋和北美洲以东的北大西洋海温偏冷(暖)。北多(少)南少(多)型前冬赤道中东太平洋以及阿拉斯加湾海温偏暖(冷),北美洲以东的北大西洋海温异常偏暖(冷)。
[Abstract]:Using daily precipitation, mean temperature, sunshine data, NECP/NCAR reanalysis data and sea surface temperature data from 80 stations in Hunan Province from 1961 to 2013, The main distribution types of low temperature overcast and rainy days and the background field of atmospheric circulation and the distribution characteristics of sea surface temperature before winter were analyzed in Hunan Province in recent 53 years. The results show that: (1) the main types of spatial distribution of low temperature overcast and rainy days in Hunan Province are the consistent type of the whole province and the different types of the north-south facies. (2) when the Eurasian continent is in the middle and high latitudes, it is affected by the East Asian trough. Combined with lower layer cold and warm air confluence and better humidity conditions, it is advantageous to the occurrence of multiple types of low temperature overcast rain. On the contrary, when the middle and high latitudes of Eurasia are controlled by high pressure and the whole lower middle and eastern part is affected by abnormal northerly wind and negative relative humidity, the low temperature overcast rain is easy to occur. When the northern part of Hunan is affected by the low trough and is a high relative humidity region, it is easy to have low temperature overcast rain in the north, more in the south and less in the south. However, when the south of Hunan is affected by the low trough and topography, the Nanling static front appears, and the south is a high relative humidity region. (3) the warm (cold) sea surface temperature in the equatorial Middle East Pacific and the Gulf of Alaska is warm (cold) before winter, and the sea surface temperature in the North Atlantic Ocean east of North America and the northwest Pacific Ocean is cold (warm). The North and South SST is warm (cold) in the equatorial Middle East Pacific Ocean and the Gulf of Alaska, and the North Atlantic SST to the east of North America is warmer (cold).
【作者单位】：湖南省气象科学研究所;气象防灾减灾湖南省重点实验室;湖南省郴州市气象局;
【基金】：湖南省气象局短平快课题“湖南春播育秧期低温阴雨灾害环流异常特征及其预测”资助
【分类号】：S511;S161

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