ISSN 1000-0526
CN 11-2282/P
CN 11-2282/P
Archive > Volume 48 Issue 12 > 2022,48(12):1617-1628. DOI:10.7519/j.issn.1000-0526.2022.071501 Prev Next
Comparison of Raindrop Spectrum Characteristics of Rainfall Caused by Two Typhoons
- Article
- Figures
- Metrics
- Preview PDF
- Reference
- Related
- Cited by
- Materials
Abstract:
The second generation laser raindrop spectrum data of Parsivel in Xuzhou and Xinyi in Jiangsu〖JP〗 Province are used to analyze the precipitation in different stages caused by typhoons Rumbia and Lekima from 2018 to 2019. The results are as follows. Small- and medium-sized raindrops are with weak rain intensity and when the intensity increases the diameters of raindrops increase. There are more big raindrops in heavy rain. With much more small and medium raindrops， the “Lekima” precipitation event has the low centroid characteristics of precipitation caused by tropical typhoon. Contrarily, with much more big raindrops, the “Rumbia” precipitation event has the characteristic of precipitation caused by extratropical typhoon. During both of the heavy rain events, there are larger average spectrum widths and diameters of raindrops, higher raindrop concerntration, multi-peaks of large raindrops, which accords with the Gamma distribution, showing characteristics of convective precipitation. Large spectrum width and maximum diameter of raindrops are found in weak rain event casued by “Rumbia”, but the average diameter of raindrops is small and there were great differences between large and small drops in diameter, which basically follows the Gamma distribution, being mixed cloud precipitation. On the contrary, in weak rain event by “Lekima”, there is smaller average spectrum width, raindrop diameter and more small raindrops, and the spectral pattern is smooth, in line with the Marshall-Palmer distribution, which are characterized by stratiform cloud precipitation. The radar reflection profiles of the two-typhoon strong and weak precipitation periods also have a certain corresponding relationship with the raindrop spectrum. The higher the echo extension, the wider the 35 dBz effective precipitation echo, and more and larger raindrops are formed at high altitudes. The falling raindrops continue to collide and merge, and with the increase of the number of raindrops, the diameter increases, and the opposite is true for the weak precipitation period. Heavy rain is mainly caused by convective cloud containing more large raindrops, and also by mixed cloud. Small and medium raindrops in mixed cloud precipitation contribute most both in number and precipitation. Although there are more small and medium raindrops in convective cloud precipitation, the raindrops with larger diameters are the major contributors. Compared with the empirical relations, the typhoon precipitation derived from the actual index of Z-R relationship might be underestimated or overestimated. The empirical relations are not applicable to different types of precipitation. It is necessary to summarize the Z-R relationship applicable to different precipitation types in different places and seasons.
Keywords:
Project Supported:
Clc Number:
Mobile website
