An analytical representation of raindrop size distribution in a mixed convective and stratiform precipitating system as revealed by field observations
Abstract This study investigated a rainfall event under a typhoon influence using a 2D video disdrometer and weather radar observations to characterize raindrop size distribution (DSD) in a mixed convective and stratiform precipitating system. During the time period when both convective and stratifo...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2023-06-01
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| Series: | Atmospheric Science Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1002/asl.1155 |
| _version_ | 1827935854540095488 |
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| author | Megumi Okazaki Satoru Oishi Yasuhiro Awata Tomoro Yanase Tetsuya Takemi |
| author_facet | Megumi Okazaki Satoru Oishi Yasuhiro Awata Tomoro Yanase Tetsuya Takemi |
| author_sort | Megumi Okazaki |
| collection | DOAJ |
| description | Abstract This study investigated a rainfall event under a typhoon influence using a 2D video disdrometer and weather radar observations to characterize raindrop size distribution (DSD) in a mixed convective and stratiform precipitating system. During the time period when both convective and stratiform rainfalls existed, the DSDs generally indicated a monotonically decreasing shape with increasing particle size, with a relatively gradual decrease at intermediate particle size observed at certain times; this feature is attributed to the combined effect of convective and stratiform rainfalls. During the transitional period between convective and stratiform rainfalls, the DSDs exhibited a bimodal shape. The DSDs were well approximated by a newly proposed gamma raindrop distribution combined with exponential (GRACE) distribution function, which was defined as the sum of the exponential distribution and the gamma distribution. A comparison of the volume ratio of the exponential and gamma components of the GRACE distribution revealed that the exponential component of the DSD was larger than the gamma component in the bimodal DSD. These results suggest that the DSD became bimodal during the period when stratiform rainfall predominated because of the weakening of convective rainfall. The GRACE distribution is useful for understanding cloud‐microphysical processes in mixed stratiform and convective precipitation conditions. |
| first_indexed | 2024-03-13T08:00:51Z |
| format | Article |
| id | doaj.art-1cf3059e6c8b4657830210bb15f3494e |
| institution | Directory Open Access Journal |
| issn | 1530-261X |
| language | English |
| last_indexed | 2024-03-13T08:00:51Z |
| publishDate | 2023-06-01 |
| publisher | Wiley |
| record_format | Article |
| series | Atmospheric Science Letters |
| spelling | doaj.art-1cf3059e6c8b4657830210bb15f3494e2023-06-01T14:46:54ZengWileyAtmospheric Science Letters1530-261X2023-06-01246n/an/a10.1002/asl.1155An analytical representation of raindrop size distribution in a mixed convective and stratiform precipitating system as revealed by field observationsMegumi Okazaki0Satoru Oishi1Yasuhiro Awata2Tomoro Yanase3Tetsuya Takemi4Graduate School of Science Kyoto University Kyoto JapanResearch Centre for Urban Safety and Security Kobe University Kobe JapanGround Facilities Department Japan Aerospace Exploration Agency Tsukuba JapanRIKEN Cluster for Pioneering Research Kobe JapanDisaster Prevention Research Institute, Kyoto University Uji JapanAbstract This study investigated a rainfall event under a typhoon influence using a 2D video disdrometer and weather radar observations to characterize raindrop size distribution (DSD) in a mixed convective and stratiform precipitating system. During the time period when both convective and stratiform rainfalls existed, the DSDs generally indicated a monotonically decreasing shape with increasing particle size, with a relatively gradual decrease at intermediate particle size observed at certain times; this feature is attributed to the combined effect of convective and stratiform rainfalls. During the transitional period between convective and stratiform rainfalls, the DSDs exhibited a bimodal shape. The DSDs were well approximated by a newly proposed gamma raindrop distribution combined with exponential (GRACE) distribution function, which was defined as the sum of the exponential distribution and the gamma distribution. A comparison of the volume ratio of the exponential and gamma components of the GRACE distribution revealed that the exponential component of the DSD was larger than the gamma component in the bimodal DSD. These results suggest that the DSD became bimodal during the period when stratiform rainfall predominated because of the weakening of convective rainfall. The GRACE distribution is useful for understanding cloud‐microphysical processes in mixed stratiform and convective precipitation conditions.https://doi.org/10.1002/asl.11552DVDconvective rainfallraindrop size distributionstratiform rainfall |
| spellingShingle | Megumi Okazaki Satoru Oishi Yasuhiro Awata Tomoro Yanase Tetsuya Takemi An analytical representation of raindrop size distribution in a mixed convective and stratiform precipitating system as revealed by field observations Atmospheric Science Letters 2DVD convective rainfall raindrop size distribution stratiform rainfall |
| title | An analytical representation of raindrop size distribution in a mixed convective and stratiform precipitating system as revealed by field observations |
| title_full | An analytical representation of raindrop size distribution in a mixed convective and stratiform precipitating system as revealed by field observations |
| title_fullStr | An analytical representation of raindrop size distribution in a mixed convective and stratiform precipitating system as revealed by field observations |
| title_full_unstemmed | An analytical representation of raindrop size distribution in a mixed convective and stratiform precipitating system as revealed by field observations |
| title_short | An analytical representation of raindrop size distribution in a mixed convective and stratiform precipitating system as revealed by field observations |
| title_sort | analytical representation of raindrop size distribution in a mixed convective and stratiform precipitating system as revealed by field observations |
| topic | 2DVD convective rainfall raindrop size distribution stratiform rainfall |
| url | https://doi.org/10.1002/asl.1155 |
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