CAJ | 학술논문

The heaviest rainfall in recent six decades fell in Beijing on 21 July 2012, reaching a record of 460 mm within 18 h. This rainfall was a typical remote precipitation event related to Typhoon Vicente (1208). Observational analysis indicates that Vicente infl uenced distant heavy rainfall by transporting water vapor northward to the Beijing area. This moisture transport was mainly driven by the interaction between Vicente and the western Pacifi c subtropical high (WPSH) associated with the formation of a low-level southeasterly moisture channel. A set of numerical sensitivity experiments were performed with prescribed typhoons of diff erent intensities to investigate the interaction between Vicente and the WPSH and its eff ects on this rainstorm process. The results indicate that the WPSH interacting with typhoons of diff erent intensities may exert varying degrees of infl uence on the development of a southeasterly moisture channel, resulting in a change in rain rate and location over the Beijing area. Specifi cally, in the presence of an enhanced typhoon, the WPSH shows remarkable withdrawal to the east, which is favorable for a northward extension of the southeasterly moisture channel, thereby increasing moisture supply for the rainstorm. The WPSH tends to stretch westward in a zonal pattern if the typhoon is weakened or removed, hindering the northward extension of the moisture channel. Thus, the rainfall area may be expected to expand or contract, with corresponding increases or decreases in rain rate over the Beijing area with a strengthened or weakened typhoon, respectively.