Page 138 - 《高原气象》2022年第5期

5 期 周春花等：持续东北移和在四川盆地停滞的九龙涡结构特征比较 1231

Comparison of the Structural Characteristics of the the Jiulong Vortex

Continuing to Move Northeast and Stagnating in the Sichuan Basin

ZHOU Chunhua 1，3，4 ，XIAO Dixiang 2，3，4 ，YU Shuhua 3，4
（1. Sichuan Meteorological Disaster Prevention Technology Center，Chengdu 610072，Sichuan，China；
2. Sichuan Meteorological Observatory，Chengdu 610072，Sichuan，China；
3. Chengdu Institute of Plateau Meteorology，Chengdu 610072，Sichuan，China；
4. Heavy Rain and Drought-Flood Disaster in Plateau and Basin Key Laboratory of
Sichuan province，Chengdu 610072，Sichuan，China）

Abstract：With on-site observation data，NCEP reanalysed data and annual statistical results of the Southwest
Low Vortex，we checked information of the Southwest Vortex activities in the past ten years，The moving of the
Kowloon vortex from the vortex source area and moving to the northeast through Sichuan Basin is called the
moving out type. The one with little stagnation in Sichuan basin after the Kowloon vortex moves out of the vor‐
tex source area is called stagnation type，classified the vortex sources and paths，and focused on comparative
analysis of characteristics between moving-out type and stagnant type of Jiulong Vortex activities，such as circu‐
lation situation，heat change and power wave. The conclusion is as below，（1）at 200 hPa level，for moving-out
type，main position of South Asian High Pressure is further south and the strength is weaker，the position of high
altitude jet is further south and strength is stronger，mid-latitude area has low groove and low vortex is located in
front of high altitude groove and on the right of high altitude jet entry point. While for the stagnant type，low vor‐
tex is located near the east side of the central South Asian High Pressure.（2）At 500 hPa level，both moving-out
type and stagnant type is in the situation of two grooves and one ridge in mid and high altitude at the beginning，
as low vortex develops，moving-out type deepens the grooves in Beihu and stagnant type is controlled by high
ridge in Beihu. Low groove in low vortex of moving-out type is deeper，southwest airflow in front of the groove
leads low vortex at lower level move northeast，while stagnant type stays in the situation of“high in the east low
in the west”，thus low vortex sustains in Sichuan for a long time.（3）Regarding heat change and power wave
characteristics，both types shares the principle“central warm structure”in all altitude at the beginning，at the
peak period it changes at high verto“central cold structure”at low altitude while it maintains“central warm struc‐
ture”at high altitude. The impact of non-adiabatic heating is very obvious at the beginning and peak period. The
sensitive heating rate of moving-out type is much stronger than stagnant type，while latent heating rate of mov‐
ing-out type is much weaker than stagnant type. Another difference is that there are fronts in low vortex for mov‐
ing-out type and the atmosphere potential is unstable，while there is no fronts in low verex for stagnant type，the
moist layer is much thicker.
Key words：Jiulong vortex；synthetic analysis；structure characteristics；apparent heat source；apparent water
vapor sink