主办单位:中国气象局沈阳大气环境研究所
国际刊号:ISSN 1673-503X
国内刊号:CN 21-1531/P

气象与环境学报 ›› 2018, Vol. 34 ›› Issue (4): 45-51.doi: 10.3969/j.issn.1673-503X.2018.04.006

• 论文 • 上一篇    下一篇

2013年夏季湖南省持续高温干旱变化特征及其成因分析

张剑明  段丽洁   

  1. 湖南省气候中心,湖南 长沙 410118
  • 收稿日期:2017-05-11 修回日期:2017-07-03 出版日期:2018-08-31 发布日期:2018-09-03

Characteristic and formation analysis of a persistent high temperature and drought event in Hunan province during 2013 summer

ZHANG Jian-ming  DUAN Li-jie   

  1. Hu'nan Climate Center, Changsha 410118, China
  • Received:2017-05-11 Revised:2017-07-03 Online:2018-08-31 Published:2018-09-03

摘要:

利用湖南省97个气象站点逐日气温和降水观测资料,结合再分析资料,分析了2013年夏季湖南省持续高温干旱的变化特征及其可能成因。结果表明:2013年夏季湖南省平均高温日数为44 d,主要高温时段为6月15—25日、6月29日至8月18日、8月21—30日,97个气象站中有32个气象站高温日数刷新历史同期最高记录。2013年夏季湖南全省大范围的气象干旱自6月15日前后开始,7月28日至8月20日重度以上干旱范围超过50%以上。西太平洋副热带高压的持续异常偏强、偏西,控制中国江南地区,是2013年夏季湖南省高温干旱最重要最直接的原因。在对流层高层,南亚高压持续偏强、偏东且偏北,有利于西太平洋副热带高压偏强和偏西的维持,从而导致江南地区持续受异常下沉运动控制,对流活动明显受到抑制,江南西部和华南北部地区为水汽通量的辐散中心,不利于水汽的堆积。

关键词: 高温日数, 干旱范围, 副热带高压, 环流异常, 水汽

Abstract:

Based on observational data of daily temperature and precipitation at 97 meteorological stations in Hunan province and the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis data, the characteristics and formation of a persistent high temperature and drought events during summer season in 2013 in Hunan province were analyzed. The results showed that the mean number of days with high temperature in Hunan province is 44 d, and these high temperature days occur mostly in the periods of June 15-25, from June 29 to August 18, and August 21-30. The numbers of days with high temperature at 32 stations in 2013 are larger than the historical records in the same period. The large-scale meteorological drought in Hunan province begins in the mid-June of 2013, and the area of severe and even heavier drought is over half area of the province from July 28 to August 20. The Subtropical High over the western Pacific that is abnormally and persistently strong and locates westward controls the Jiangnan region, which is the most important and direct influencing factor  of this high temperature and drought event in Hunan province. In the upper troposphere, the South Asian High is persistently strong and moves eastward or northward, which is favorable to the maintenance of the western Pacific Subtropical High. This leads to the continuous subsidence motions of air flows over the Jiangnan region and the significant suppression of convective activity. Meanwhile, the divergence center of water vapor flux is located at the western of Jiangnan region and the northern part of South China, which is unfavorable to the accumulation of water vapor.

Key words: Day number with high temperature, Drought area, Subtropical High, Abnormal circulation, Water vapor

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