Journal of Arid Meteorology ›› 2022, Vol. 40 ›› Issue (5): 748-763.DOI: 10.11755/j.issn.1006-7639(2022)-05-0748

• Research on Severe Drought in the Yangtze River Basin in 2022 • Previous Articles     Next Articles

Characteristics of high temperature, drought and circulation situation in summer 2022 in China

LIN Shu1(), LI Hongying2, HUANG Pengcheng1, DUAN Xinyu1   

  1. 1. Lanzhou Regional Climate Center, Lanzhou 730020, China
    2. Jiuquan Meteorological Bureau of Gansu Province, Jiuquan 735000, Gansu, China
  • Received:2022-10-10 Revised:2022-10-18 Online:2022-10-31 Published:2022-11-10

2022年夏季我国高温干旱特征及其环流形势分析

林纾1(), 李红英2, 黄鹏程1, 段欣妤1   

  1. 1.兰州区域气候中心,甘肃 兰州 730020
    2.甘肃省酒泉市气象局,甘肃 酒泉 735000
  • 作者简介:林纾(1964—),女,福建福州人,正研级高级工程师,主要从事短期气候预测和气候变化研究. E-mail:treewest@163.com
  • 基金资助:
    国家重点研发计划项目(2018YFC1505601);甘肃省气象局面上项目(Ms2022-18)

Abstract:

In the summer of 2022, there was a climate anomaly with the highest average temperature and less precipitation since 1961 in China, accompanied by the strongest nationwide high temperature processes (except northeastern China) and a wide range and strong summer drought in the middle and lower reaches of the Yangtze River and Sichuan and Chongqing. For the persistence and extremity of the high temperature and drought event in this summer in China, this paper analyzes the temporal and spatial distribution characteristics and cirulation situation based on the daily maximum temperature and precipitation of 2162 meteorological stations in China from June to August 2022 and the daily reanalysis data of NCEP (National Centers for Environmental Prediction) /NCAR (National Center for Atmospheric Research), which will be of some references for the forecast of summer high temperature and drought with different time scales in southern China. The results show that in the summer of 2022, a total of 48 198 high temperature events occurred in 76.0% of the stations in China, among which 36.6% of the stations experienced 3001 extreme high temperature events. The stations with more than 20 extreme high temperature events all distributed in the Sichuan Basin, and the high temperature situation was more severe this year than the typical high temperature years since the 21st century. The nationwide high temperature process lasted from June 13 to August 30, a total of 79 days, and the strongest high temperature period was from August 11 to 24. According to the comprehensive ranking of high temperature station numbers, duration, intensity and impact range from strong to weak, the order is East China, Central China, southwestern China, northwestern China, North China and South China, among which, the extreme was the most in southwestern China, while there was no high temperature in northeastern China. The spatial and temporal distribution of drought is basically similar to that of high temperature, and the strongest drought period in China was in mid-August. In the summer of 2022, the 500 hPa over the middle and high latitudes of Eurasia showed a “two ridges and one trough” pattern, especially in July and August, the high pressures ridge near the Ural Mountains and the Sea of Okhotsk formed periodic blocking high. The strong subtropical system blocked the active cold air between the two high pressures to the north of 50°N most of the time, resulting in the pattern of “flood in the north and drought in the south” in China. The Iran high at low latitude extended abnormally to the east, and the western Pacific subtropical high was slightly northward and abnormally extended to the west. The air flow in the control area of the high pressure zone formed by the long-term connection of the two high pressures diverged and sank, which continuously blocked the transport of water vapor to the middle latitude, and was not conducive to the precipitation in the Yangtze River basin. At the same time, the south Asia high at high-level was abnormally eastward and moved to the opposite direction of western Pacific subtropical high at mid-level, which superimposed over the range of 80°E-120°E in the middle and late August, resulting in a stable barotropic structure of the high pressure system controlling a wide range of China, and the center was located over Sichuan and Chongqing region, which made Sichuan-Chongqing region become the large value center of high temperature days and the extreme high temperature event times.

Key words: high temperature, extreme high temperature event, drought, subtropical high, south Asia high, the summer of 2022

摘要:

在气候变暖背景下,2022年夏季我国出现1961年以来平均气温最高和降水量次少的气候异常,并伴有最强的全国性(东北地区除外)高温过程和长江中下游及川渝地区大范围强伏旱。针对这次高温干旱的持续性和极端性,本文基于2022年6—8月全国2162个气象站逐日最高气温和降水量以及NCEP(National Centers for Environmental Prediction)/NCAR(National Center for Atmospheric Research)逐日再分析资料等,分析其时空分布特征及环流形势,将对今后我国南方地区夏季高温干旱不同时间尺度的预报预测有一定参考价值。结果表明:2022年夏季,全国76.0%的站共出现48 198次高温,其中36.6%的站累计出现3001次极端高温事件,20次以上极端高温事件的站点均分布在四川盆地,高温状况远超21世纪以来的典型高温年份。全国性的高温过程从6月13日持续到8月30日,共计79 d,高温最强时段在8月11—24日。按照高温发生站次、持续时间、影响范围、强度等由强到弱综合排序,依次是华东、西南、华中、西北、华北和华南地区,其中西南地区极端性最强,而东北地区未出现高温。干旱时空分布特征与高温基本相似,全国最强干旱时段在8月中旬。2022年夏季,500 hPa欧亚中高纬度呈“两脊一槽”型,尤其在7—8月乌拉尔山和鄂霍次克海附近高压脊形成阶段性阻塞高压,强盛的副热带系统将两高之间活跃的冷空气大部分时段阻挡在50°N以北,造成我国“北涝南旱”的格局;低纬度的伊朗高压异常东伸,西太平洋副热带高压略偏北且异常西伸,两高压长时间贯通形成的高压带控制区气流辐散下沉,并持续阻碍水汽向中纬度输送,不利于长江流域产生降水。同时,对流层高层南亚高压异常偏东,与中层的西太平洋副热带高压相向而行,于8月中下旬在80°E—120°E范围内叠加,致使控制我国大范围的高压系统呈稳定正压结构,中心位于川渝上空,致使川渝地区成为高温日数和极端高温事件次数的高值中心。

关键词: 高温, 极端高温事件, 干旱, 副热带高压, 南亚高压, 2022年夏季

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