摘要
基于1980~2019年11月至翌年3月全国低温灾害性天气文字记录,结合高精度再分析资料NASA MERRA2,构建了我国低温灾害(低温、降温、冰冻、雨雪、雪灾)的精细化格点数据,采用线性趋势分析、集合经验模态分解(EEMD)和小波分析等方法研究了我国低温灾害的时空分布特征,初步描绘了我国低温灾害图谱。研究表明:干低温灾害(低温、降温、冰冻)往往不是单一灾种致灾,而湿低温灾害(雨雪、雪灾)多为单一灾种致灾。不同灾种的发生频次具有显著的区域和季节内差异:1月低温的致灾范围最广,发生频次由南向北呈现“高—低—次高”的三极型分布;降温灾害在12月发生频次最多,呈“东高西低”分布;雨雪灾害在1~2月的南方地区发生最多;雪灾发生频次明显多于前四个灾种,多分布在牧区等高敏感地带。就全国而言,干低温和雨雪灾害的发生频次和受灾面积呈现长期上升趋势,而雪灾则在前后冬有相反趋势,其受灾面积的上升趋势主要来自1月,发生频次的减少趋势来自3月;干低温和雨雪灾害的灾情指数年代际变率在2000年之后波动增加,而雪灾则在2000年之前变率较大;大部分低温灾种(除雪灾)发生频次的年际变率在2005年后均有显著增加。单一灾种中,仅降温受灾面积有显著的上升趋势,主要归因于1月。复合灾种中,降温与湿低温的组合呈显著上升趋势。
According to the nationwide records of cold weather hazards combined with high-precision reanalysis data(NASA MERRA2)during the winter season(November–March)from 1980 to 2020,a daily dataset of low-temperature hazards(including low temperature,abrupt temperature drop,freezing,rain and snow,and snowstorm)in China was constructed.Through linear trend analysis,ensemble empirical mode decomposition,and wavelet analysis,the temporal and spatial distribution characteristics of various cold hazards in China were studied.The results show that cold hazards without precipitation(namely low temperature,abrupt temperature drop,and freezing)are generally caused by a combination of two or more types of cold hazards,while cold hazards with precipitation(namely rain and snow,snowstorm)are generally caused by a single type.The occurrence frequency of various cold hazards exhibits significant regional and seasonal differences.Low-temperature hazards affected the widest area in January,and the occurrence frequency followed a“high–low–subhigh”distribution from south to north.The occurrence frequency of abrupt temperature drop was the highest in December with a distribution pattern of“high-in-the-East and low-in-the-West”.Rain and snow occurred most frequently in southern China from January to February.Snowstorms occur more frequently than other types of cold hazards and are mainly distributed in susceptible regions such as pastoral areas.On the national scale,the occurrence frequencies and affected areas of most cold hazards(except snowstorms)exhibit a long-term increasing trend with time.However,the occurrence of snowstorms exhibits an increasing trend in the affected areas,particularly in January,and a decreasing trend in the occurrence thereafter,particularly in March.The interdecadal variability of the occurrences and affected areas of most cold hazards(except snowstorms)increased after the 2000s,while the interdecadal variability of snowstorms was higher prior to the 2000s.The interannual variability of the frequency of cold hazards(except snowstorms)considerably increased after 2005.Among single-type hazards,only the areas affected due to abrupt temperature drops showed a significantly increasing trend,particularly in January.For the compound-type cold hazards,the combination of abrupt temperature drop and cold hazards with precipitation showed a significant increase.
作者
虞越越
张伶俐
管兆勇
杨汶雯
YU Yueyue;ZHANG Lingli;GUAN Zhaoyong;YANG Wenwen(Key Laboratory of Meteorological Disaster,Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environment Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC–FEMD)/School of Atmospheric Sciences,Nanjing University of Information Science and Technology,Nanjing 210044;Jilin Changbaishan Meteorological Bureau,Changbaishan,Jilin 133613)
出处
《大气科学》
CSCD
北大核心
2023年第5期1355-1374,共20页
Chinese Journal of Atmospheric Sciences
基金
国家重点研发计划项目2019YFC1510201
江苏省自然科学基金项目BK20211288
国家级大学生创新训练项目202110300001Z。
关键词
低温灾害
灾害面积
灾害频次
长期趋势
多时间尺度变化
集合经验模态分解
Cold weather hazard
Affected area of hazards
Occurrence frequency of hazards
Long-term trend
Multiscale temporal change
Ensemble empirical mode decomposition