Relationship Between the Change in Size of Tropical Cyclones and Spatial Patterns of Precipitation. Issue 17 (11th September 2019)

• Record Type: Journal Article
• Authors: Tsuji, Hiroki; Nakajima, Kensuke
• Is Part Of: Journal of geophysical research. Volume 124:Issue 17/18(2019)
• Page Start: 9948
• Page End: 9962
• Publication Date: 2019-09-11
• Subjects: tropical cyclone size change -- precipitation -- inertial stability; Atmospheric physics -- Periodicals; Geophysics -- Periodicals; 551.5
• DOI: 10.1029/2019JD030404
• Languages: English
• ISSNs: 2169-897X

Abstract

Abstract: The relationship between the size change of tropical cyclones (TCs) and radial distribution of precipitation was investigated for TCs occuring over the western North Pacific Ocean with satellite observation data. The size of a TC is defined as the radial extent of 15 m s −1 winds (R15). The spatial distribution of precipitation was investigated by extracting two subperiods, which are the size‐increasing period and the size‐stationary period, as determined from R15 evolution. The results show a contrast that during the size‐increasing period, precipitation falls both inside and outside the R15, whereas during the size‐stationary period, it is concentrated near the center of the TC and falls less around and outside R15. This contrast is also confirmed statistically by composite analysis using 64 TC cases. Further analysis reveals that this contrast does not depend on the intensity or the change in intensity of the TC, which indicates that the area of precipitation related to the intensity or intensity change of TCs is different from that related to the size change of TCs. Finally, we examined the radial distribution of inertial stability in TCs and found that precipitation during the size‐stationary period occurs in a region with a higher inertial stability than that which occurs during the size‐increasing period. Key Points: Rainfall on the outskirts of tropical cyclones (TCs) enlarges TC size, while rainfall concentrated near the center does not The relationship between rainfall and TC size change is confirmed in TCs with wide ranges of size, intensity, and intensity change A larger amount of precipitation occurs in a lower inertial stability region when the TC grows in size