Page 206 - 《高原气象》2026年第1期

高 原 气 象 45 卷
202

Climatic Type Characteristics of the Winter Yunnan-Guizhou

Quasi-Stationary Front

2， 3
REN Manlin ， BAI Hui ， YAN Xiaodong ， XIA Yang ， LI Zhongyan ， ZHENG Bei 1
1， 3
1
1
2
（1. Guizhou Institute of Mountain Meteorological Science Research， Guiyang 550002， Guizhou， China；
2. Climate Center of Guizhou Province， Guiyang 550002， Guizhou， China；
3. Key Laboratory of the Mountain Climate and Resources of Guizhou Province， Guiyang 550002， Guizhou， China）
Abstract： Based on the topographic characteristics of the Yunnan-Guizhou Plateau， the objective standard index
of the intensity of the Yunnan-Guizhou quasi-stationary front in winter is defined by using the FNL atmospheric
reanalysis data of 24 years （2000-2023）， According to this index， the strong quasi-stationary front events are se‐
lected， the temperature， humidity and wind structure of the strong quasi-stationary front events were studied，
and the characteristics of different types of strong quasi-stationary front events are compared and analyzed. The
results show that： （1） the Yunnan-Guizhou Quasi-Stationary Front manifests as a dense band of isentropic lines
（θ ） in the mid-to-lower troposphere， with the frontal zone tilting eastward with increasing altitude and the gradi‐
se
ent distributed in a north-south band. Strong quasi-stationary front events occur most frequently in January
（39%） and February （33%）， and their occurrence frequency shows significant interannual variability.
（2） Strong Quasi-Stationary Front is characterized by a dense band of isentropic lines （θ ） at the junction of Yun‐
se
nan and Guizhou. Within the frontal zone， the wind exhibits convergence between northeastern and southwestern
winds， with high humidity areas located in the central and western parts of Guizhou to the east of the front. Be‐
low 700 hPa， there is a stark contrast between the notably warmer western region and the significantly cooler
eastern region. Below 800 hPa， abnormal easterly winds appear in the eastern area and transition into upward mo‐
tion around 750 hPa， leading to an enhanced upward transport of moisture. This， in turn， promotes an abnormal
structure with upper-level moisture and lower-level dryness to the west of the front.（3） Based on the strength of
the cold and warm air on either side of the stationary front， strong quasi-stationary front events are classified into
two types： the Cold Anomaly in the East （CE， 75%） and the Warm Anomaly in the West （WW， 13%）. On the
surface， the frontal position of WW-type events shifts slightly eastward compared to CE-type events. In CE-type
events， the stronger cold anomaly extends westward to 104° E and upward to 750 hPa， while in WW-type
events， the stronger warm anomaly extends eastward， with the cold anomaly limited to the east of 106°E and
contracting downward below 850 hPa. Below 800 hPa， the abnormal easterly winds in CE-type events are stron‐
ger and extend higher than those in WW-type events， promoting more moisture to ascend along the terrain and be
transported westward. As a result， the center of positive relative humidity anomalies in WW-type events is locat‐
ed further east compared to CE-type events.
Key words： Yunnan-Guizhou quasi-stationary front； winter； vertical structure； different types