[A-AS02] Extreme Events: Observations and Modeling

[AAS02-03] Estimation of moisture sources within an explosive cyclone over the Sea of Japan using an isotopic regional spectral model

★Invited Papers

*李 肖陽¹、川村 隆一¹、杉本 敦子^2,3、芳村 圭^4,5 (1.九州大学　大学院理学研究院　地球惑星科学部門、2.北海道大学　北極域研究センター、3.北海道大学　大学院環境科学院、4.東京大学　大気海洋研究所、5.東京大学　生産技術研究所)

キーワード：爆弾低気圧、水起源、温暖前線、寒冷前線、水同位体領域モデル、水安定同位体

In this study, we identified water origins and clarified moisture transport processes within the explosive cyclone migrating poleward across the Sea of Japan (SJ) on November 30, 2014, by using an isotopic regional spectral model. Regarding the total precipitable water and condensation in the vicinity of the cyclone center, a replacement of water origins occurred during the cyclone development, resulting from a shift of the moisture transport from the warm conveyor belt (WCB) to the cold conveyor belt (CCB) and dry intrusion (DI). At the early stage, the WCB transported large amounts of moisture from the East China Sea and Kuroshio (ECS & KS) into the cyclone’s inner region. While at the rapidly developing stage, the CCB and DI conveyed more moisture from the Northwest Pacific Ocean (NWP) and SJ, respectively, to the cyclone center area. Compared with the local moisture, the contribution of remote moisture was dominant in the vicinity of the cyclone center. With respect to the water origins of condensation within the cyclone frontal system at the rapidly developing stage, the NWP vapors, principally transported by the CCB, contributed 35.5% of the condensation in the western warm front. The ECS & KS moisture, conveyed by the WCB, accounted for 32.4% of the condensation in the cold and eastern warm fronts. In addition, condensation from the SJ, which was mainly triggered by the DI and induced by the topography, occurred on the west coast of the mainland of Japan and near the cyclone center. The spatial distribution of the isotopic composition in condensation also supports the water origin results. These results point the way toward better understanding of where the moisture is evaporated, how the moisture is transported, and where the moisture is condensed. The findings can be used for weather forecasting, disaster preparedness, and allocation of water and energy resources in association with extratropical cyclones.