Spatiotemporal Characteristics of Tropical Cyclone Induced Remote Moisture Transport affecting East Asia using Digraphs

Attention of tropical cyclone (TC) induced remote moisture transport has increased over the past several decades. There is significant progress of objective identification to resolve spatiotemporal merging and spitting of the moisture transport patterns using digraphs to represent clusters inside the patterns. This identification method also reflects discontinuous and uneven moisture transport. However, finding the mainstreams of these patterns still remains a challenge, which is necessary to retrieve statistical and geometric features of these patterns. To solve this issue, we assign the weight that is positive and decreases with increasing cross-border moisture transport between two clusters corresponding to two nodes to their edges to process the strongest connected component and dijkstra shortest path algorithms to find the main stream of moisture transport pathways. The frequency of TC remote transport is the highest in July over North China and Korean Peninsula and in September over South China and northern Vietnam. The statistical and geometric features of TC remote moisture transport are analyzed in the key periods and regions above. Moreover, discontinuity of moisture transport over the key periods and regions is quantified by the temporal variability of weights over the lifecycles of moisture transport patterns. Unevenness of moisture transport is quantified by the spatial variability of length of the mainstream. Vertical cross section of physical decomposition of moisture transport along the mainstream is further analyzed in this study.