Impacts of Changbai Mountain Topography on the Extreme Precipitation From Super Typhoon Maysak

Abstract

Based on hourly gridded precipitation data (0.1°) calculated by the China Meteorological Administration (CMA), the European Centre Medium-Range Weather Forecasts (ECMWF) reanalysis data, and microwave measurements, this paper investigated the extreme precipitation induced by the Typhoon Maysak in Northeast China (September 2020), using the Advanced Research dynamic core of the Weather Research and Forecasting Model (WRF-ARW). The study focused on Changbai Mountain topography and the extreme precipitation in Jilin Province. The results show that two extreme precipitation centers corresponded well to the local terrain height in Jilin Province. The Changbai Mountain range, which mainly lies in southeastern Jilin Province, affected the typhoon in three aspects: blocking drag, forcing uplift, and promoting moisture convergence. Because of the blocking drag of the mountain topography, the duration of severe precipitation was prolonged. The overlap of the area affected by the peripheral cloud band of the typhoon and the direction of the typhoon was largely responsible for the extreme rainfall. The dynamic lifting by the mountainous terrain and the reinforced moisture convergence also considerably increased precipitation. Microwave measurements show that water vapor density profile increased rapidly at the peak (14 g/m3), and the high moisture density was retained for at least 15 h in the lower layer. The prolonged, continuous, and abundant moisture transport offered a sufficient water vapor supply for this severe precipitation event. According to the estimation of precipitation rate, the increment of torrential rainfall on Changbai Mountain during the severe precipitation period reached 6.8 mm/h, about 41% of the total rainfall in this period. Finally, the topographic sensitivity test indicated that when the terrain of Changbai Mountain was lower, the convergent ascending motion, precipitable water, and storm-relative helicity were weaker, and the rainfall distribution markedly changed. This finding further verifies the importance of the Changbai orography in the extreme precipitation event induced by Typhoon Maysak.

Spatiotemporal Variation of Hourly Scale Extreme Rainstorms in the Huang-Huai-Hai Plain and Its Impact on NDVI

“…Human activities have led to global warming and increased tropical humidity, increasing precipitation in the H-Plain [95]. Human activities contribute more significantly than natural climate change to the variance in maximum daily rainfall (about 10%).…”

The Role of Changbai Mountain in an Extreme Precipitation Event in Liaoning Province, China

“…With the rapid advancement of computer technology, various numerical models have been widely employed to investigate the orographic effects on regional precipitation. Previous studies have shown that the uplifting effect of topography enhances positive vorticity on the windward slopes, fostering accelerated vertical upward motion [5]. On the other hand, the obstructive effect of topography alters the wind direction at the bottom of the Northeast cold vortex, forming new convective clouds on the windward slopes and intensifying precipitation [21].…”

“…Research indicates that large-scale circulation patterns, such as the North Atlantic Oscillation, Madden Julian Oscillation, and El Niño-Southern Oscillation, synoptic-scale disturbances, mesoscale convective systems, boundary layer convergence, and local terrain, all play pivotal roles in the dynamics of extreme precipitation [2][3][4]. Additionally, monsoonal circulation, moisture transport, and the downward propagation of high potential vorticity also influence the formation of extreme precipitation [5][6][7]. Nonetheless, predicting extreme precipitation accurately remains challenging due to the complex interaction between various physical processes across different spatial and temporal scales [8,9].…”

Possible Relationships between the Interdecadal Anomalies of Heavy Rainfall under Northeastern China Cold Vortexes and the Sea Surface Temperature (SST)

“…In early and late summer, the water vapor anomaly mainly converges in the southwest during strong NECVI years [19]. Low tropospheric relative humidity (RH) is a prominent environmental factor during the monsoon season [22] and is influenced by the effect of the terrain on the NECVHR [23,24].…”