Page 189 - 《高原气象》2023年第1期

1 期 夏 阳等：中国西南贵州地区冬季凝冻日数的气候特征及其异常成因 185

Climatic Characteristics of Winter Freezing Days in Guizhou in

Southwest China and Their Anomalous Causes

4
1
1
XIA Yang ， YAN Xiaodong ， LIU Zhihan ， HU Ping ， YAN Rui ， ZHANG Qian 5
2
3
（1. Meteorological Bureau of Liupanshui， Liupanshui 553000， Guizhou， China；
2. Guizhou Climate Center， Guiyang 550002， Guizhou， China；
3. Chengdu University of Information Technology， Chengdu 610225， Sichuan， China；
4. Meteorological Bureau of Tongren， Tongren 554300， Guizhou， China；
5. College of Atmosphere and Remote Sensing， WuXi University， Wuxi 214000， Jiangsu， China）
Abstract： Based on daily gauge station datum， monthly reanalysis datasets from NCEP/NCAR and monthly
SST data from Hadley Center in UK （HadISST）， The climatic characteristics of freezing days and their causes
have been studied on. It is found that there are 69 stations （85. 2%） of longest persistent days in the single freez‐
ing processes and 63 stations （77. 8%） of total winter freezing days occurred in 1976， 1983 and 2007， Weining's
66 d （1976） and 39 d （2007） being the longest events respectively. The main mode of winter freezing days in
Guizhou which the center is in central showed a consistent distribution in the whole region with a variance of
65. 04%. When the winter freezing days in Guizhou were abnormally large， the abnormally active Ural Mountain
blocking high pressure and the abnormally strong East Asian Trough were conducive to the formation of stable
meridional circulation in East Asia. while the low value system in Central Asia guided the cold air in front of the
blocking high and the Mongolian cold high southward， formed a shallow abnormal cold pad in the lower tropo‐
sphere of Guizhou and its north. At the same time， the warm and humid air flow in the middle and lower tropo‐
sphere from the Bay of Bengal and the South China Sea crawled and uplifted along the edge of the cold air pile
near the Yunnan-Guizhou Quasi-Stationary Front under the action of the abnormal circulation circle， and formed
an unstable vertical stratification anomaly of warm up and cold down in the middle and lower troposphere over
Guizhou， resulting in the formation of winter freezing in Guizhou. In addition， the wave disturbance energy
propagation from North Atlantic and low latitude tropical played an important role in the formation and mainte‐
nance of the blocking situation in the middle and high latitudes and the anomaly of the low trough system in Eur‐
asia. When the freezing days were abnormal less， the situation is opposite. Finally， there is a closely relationship
between the winter freezing days anomaly in Guizhou with the La Niña event in the equatorial Middle East Pacif‐
ic and the SST anomaly in the North Pacific， Indian Ocean， and South China Sea.
Key words： Guizhou； freezing days； climatic characteristics； circulation anomaly