Page 230 - 《高原气象》2026年第2期

高 原 气 象 45 卷
530

Second-Order Moist Potential Vorticity in Terrain-Following Coordinate

and its Application in Improving Numerical Precipitation Prediction

1， 4
1
3
YANG Cha ， LI Na ， HU Yuntao ， RAN Lingkun ， ZHAO Xingna 1
2， 3
（1. Xichang Satelite Launch Center， Xichang 615000， Sichuan， China；
2. School of Resources and Environmental Engineering of Ludong University， Yantai 264025， Shandong， China；
3. Institute of Atmospheric Physics， Chinese Academy of Sciences， Beijing 100029， China；
4. College of Computer Science and Technology， National University of Defense Technology， Changsha 410073， Hu’nan， China）

Abstract： For the general problem of rainstorm under complex terrain， the use of isobaric coordinates can not
accurately analyze and predict the intensity and movement of mountain rainstorm due to the intersection of the
lower troposphere isobaric surface and the ground. In order to improve the rainstorm prediction level under com‐
plex terrain conditions， it is necessary to develop a set of rainstorm prediction methods under the terrain follow‐
ing coordinate system， which can not only directly reflect the terrain impact in physical quantities， but also avoid
the differences in dynamic analysis of different regions caused by terrain in local rectangular coordinates or iso‐
baric coordinates. Taking the second-order moist potential vorticity in the ensemble dynamic factor heavy rainfall
forecasting method as an example， this paper studies and attempts dynamic heavy rainfall forecasting under the
terrain-following coordinate system. It derives the mathematical form of the second-order moist potential vortici‐
ty in the terrain following coordinate system， and then explores the physical information contained in the second-
order moist potential vorticity in the terrain following coordinate system and the possibility of improving the pre‐
cipitation forecast through case analysis and comparison with the second-order moist potential vorticity in the iso‐
baric coordinate system. Furthermore， the analog method is introduced to conduct forecast verification on quanti‐
tative precipitation forecasting using the second-order moist potential vorticity in the terrain-following coordinate
system. The verification results show that in the ETS score of summer precipitation forecast in 2016 and 2017，
The score of precipitation similarity correction method based on topographic second-order moist potential vortici‐
ty is higher than that of original forecast precipitation of GFS model.
Key words： terrain following coordinate； second-order moist potential vorticity； anology method； analogous
parameter； precipitation forecast improvement