[A-AS04] 台風研究の新展開～過去・現在・未来

[AAS04-05] Consistent Pattern of Rainfall Asymmetry in Binary Tropical Cyclones

*Haoyan Liu¹、Jian-Feng Gu²、Yuqing Wang³ (1.Hohai University、2.Nanjing University、3.University of Hawaii at Manoa)

キーワード：binary tropical cyclones, asymmetric rainfall

The rainfall distribution in each TC of binary-TC systems may be more complicated than that in a single TC. Whether the rainfalls of binary TCs have some special features has not been studied before. This observational study examines the rainfall distribution in binary TCs over the western North Pacific during 2001 to 2020. The results show that the asymmetric component of TC rainfalls strengthened with the decreasing of the separation distance between the two TCs. If orient binary TCs in the west-east direction, the rainfalls of the western TC were distinctly weakened in its Quadrant IV. The suppression effect cannot be neglected within 2050-km separation distance between binary TCs. Composite analyses indicate that the asymmetric rainfalls in one of the binary TCs were related to the deep-layer vertical wind shear (VWS) induced by its companion. The consistent pattern of rainfall asymmetry indicates a highly predictable component of rainfall distribution at vortex-scale in binary TCs and can help improve the precipitation forecast of binary TCs.