云南夏秋连续干旱事件及前期海平面气压异常信号  

Identifying Early Abnormal Signals of Sea-Level Pressure for Continuous Drought Events in Yunnan during Summer and Autumn

作　　者：王秀英[1,2] 肖子牛 孙畅[1] WANG Xiuying;XIAO Ziniu;SUN Chang(State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics,Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029;Pu′er Meteorological Bureau of Yunnan Province,Pu′er,Yunnan Province 665000)

机构地区：[1]中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室,北京100029 [2]云南普洱市气象局,云南普洱665000

出　　处：《气候与环境研究》2023年第3期275-285,共11页Climatic and Environmental Research

基　　金：云南省普洱气象局李崇银院士工作站项目2018IC150;国家自然科学基金项目U1902209。

摘　　要：近十多年来云南地区多次发生极端的季节性连续干旱,尤其是夏季、秋季的连续干旱会加重传统冬、春季节干旱的危害,给当地经济和社会活动造成了严重的影响。本文基于1970~2019年云南省气象局120站降水数据及NCEP海平面气压场数据,从降水持续性异常指数出发,分析了云南夏、秋季节连续干旱事件发生的演变特征,进而探究了该区域夏秋连续干旱事件与前期4月海平面气压的可能联系,以期能够在极端干旱的预报中提供帮助。研究结果表明:(1)云南夏秋降水持续性异常的主要特征为全省一致的偏多或偏少;(2)云南夏秋连续干旱事件发生前期表现为3个区域海平面气压异常的组合,分别为北大西洋、北印度洋和中太平洋海平面气压异常;(3)由前期4月上述关键信号构建的组合信号指数,能够较好地表征云南夏季、秋季的降水连续异常,是具有意义的潜在前期预报信号。Over the past decade,Yunnan Provinces have experienced multiple instances of seasonal continuous drought.In particular,the prolonged drought in summer and autumn has exacerbated the negative effects of the drought in winter and spring,detrimentally impacting the local economic and social activities.As a result,the underlying reasons for the continuous droughts have become a major topic of concern.This paper utilizes precipitation data from 120 Yunnan Meteorological Bureau stations and sea-level pressure data of NCEP spanning the period from 1970 to 2020.This paper aims to analyze the evolution characteristics of continuous drought events in summer and autumn in Yunnan Province using the precipitation persistence anomaly index.Additionally,it investigates the possible relationship between drought events during summer to autumn and sea-level pressure in early April.The findings of this paper indicate that:(1)The primary characteristics of precipitation persistence anomaly in summer and autumn correspond to the consistent positive or negative anomaly in Yunnan.(2)The early stage of the continuous drought events in summer and autumn in Yunnan is the result of a combination of sea-level pressure anomalies in three regions,namely,the North Atlantic Ocean,the North Indian Ocean,and the Central Pacific Ocean.(3)Based on the previous three signals,an index,referred to as the SAP(Summer and Autumn Precipitation)index,can be constructed in the month of April.The SAP index can effectively represent the continuous precipitation anomaly in summer and autumn in Yunnan.This index demonstrates remarkable potential as an early prediction signal for continuous drought events in the region.The results predicted by this study can provide valuable insights for improving the prediction of such extreme events in Yunnan.

关 键 词：连续干旱 前期预测信号 海平面气压异常 

分 类 号：P426[天文地球—大气科学及气象学]