Raindrop size distribution (DSD) during the passage of tropical cyclone Nivar: effect of measuring principle and wind on DSDs and retrieved rain integral and polarimetric parameters from impact and laser disdrometers
<p>Raindrop size distribution (DSD) observations during the passage of landfalling tropical cyclone Nivar by impact (JWD) and laser (LPM and PARSIVEL) disdrometers are used to unveil the DSD characteristics in the eyewall as well as the inner and outer rainbands. Disdrometer measurements colle...
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2022-11-01
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| Series: | Atmospheric Measurement Techniques |
| Online Access: | https://amt.copernicus.org/articles/15/6705/2022/amt-15-6705-2022.pdf |
| _version_ | 1811189174662856704 |
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| author | B. Radhakrishna |
| author_facet | B. Radhakrishna |
| author_sort | B. Radhakrishna |
| collection | DOAJ |
| description | <p>Raindrop size distribution (DSD) observations during the passage of landfalling tropical cyclone Nivar by impact (JWD) and laser (LPM and PARSIVEL) disdrometers are used to unveil the DSD characteristics in the eyewall as well as the inner and outer rainbands. Disdrometer measurements collected at the same location are used to study the effect of wind, measuring principle, and hardware processing on the DSDs and, in turn, on estimated rain integral and polarimetric parameters. The concentration of raindrops of diameters between 0.7 and 1.5 mm increases with rain rate (<span class="inline-formula"><i>R</i></span>) in all the regions of Nivar, while the magnitude of the increase is higher in the eyewall than in the inner and outer rainbands. The DSD characteristics reveal that for a given <span class="inline-formula"><i>R</i></span>, relatively larger reflectivity (<span class="inline-formula"><i>Z</i></span>) and mass-weighted mean diameter (<span class="inline-formula"><i>D</i><sub>m</sub></span>) are found in the outer rainband, and smaller <span class="inline-formula"><i>Z</i></span> and <span class="inline-formula"><i>D</i><sub>m</sub></span> are found in the eyewall than in other regions of a tropical cyclone (TC). Raindrops of diameter 3 mm in size are observed frequently in inner and outer rainbands; however, they are infrequent in the eyewall at <span class="inline-formula"><i>R</i></span> greater than 5 mm h<span class="inline-formula"><sup>−1</sup></span>. The DSDs and estimated rain integral and polarimetric parameters are distinctly different for various disdrometers at similar environmental conditions. Raindrops greater than 3 mm in size are infrequent in the JWD recordings, while they are frequent in the LPM and PARSIVEL, indicating that LPM and PARSIVEL overestimate the raindrop size when the fall path deviates from nadir due to horizontal wind. The wind effect on the recorded DSD as well as estimated rain integral and polarimetric parameters are not uniform in various regions of Nivar for different disdrometers as the measuring principle and hardware processing further influence these effects. Along with the differences in measured DSD spectra, the resonance effects at X band for raindrops greater than 3 mm cause variations in the estimated polarimetric parameters between the disdrometers.</p> |
| first_indexed | 2024-04-11T14:31:34Z |
| format | Article |
| id | doaj.art-035a12aa55c4461289bee176ab0097c2 |
| institution | Directory Open Access Journal |
| issn | 1867-1381 1867-8548 |
| language | English |
| last_indexed | 2024-04-11T14:31:34Z |
| publishDate | 2022-11-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Measurement Techniques |
| spelling | doaj.art-035a12aa55c4461289bee176ab0097c22022-12-22T04:18:33ZengCopernicus PublicationsAtmospheric Measurement Techniques1867-13811867-85482022-11-01156705672210.5194/amt-15-6705-2022Raindrop size distribution (DSD) during the passage of tropical cyclone Nivar: effect of measuring principle and wind on DSDs and retrieved rain integral and polarimetric parameters from impact and laser disdrometersB. Radhakrishna<p>Raindrop size distribution (DSD) observations during the passage of landfalling tropical cyclone Nivar by impact (JWD) and laser (LPM and PARSIVEL) disdrometers are used to unveil the DSD characteristics in the eyewall as well as the inner and outer rainbands. Disdrometer measurements collected at the same location are used to study the effect of wind, measuring principle, and hardware processing on the DSDs and, in turn, on estimated rain integral and polarimetric parameters. The concentration of raindrops of diameters between 0.7 and 1.5 mm increases with rain rate (<span class="inline-formula"><i>R</i></span>) in all the regions of Nivar, while the magnitude of the increase is higher in the eyewall than in the inner and outer rainbands. The DSD characteristics reveal that for a given <span class="inline-formula"><i>R</i></span>, relatively larger reflectivity (<span class="inline-formula"><i>Z</i></span>) and mass-weighted mean diameter (<span class="inline-formula"><i>D</i><sub>m</sub></span>) are found in the outer rainband, and smaller <span class="inline-formula"><i>Z</i></span> and <span class="inline-formula"><i>D</i><sub>m</sub></span> are found in the eyewall than in other regions of a tropical cyclone (TC). Raindrops of diameter 3 mm in size are observed frequently in inner and outer rainbands; however, they are infrequent in the eyewall at <span class="inline-formula"><i>R</i></span> greater than 5 mm h<span class="inline-formula"><sup>−1</sup></span>. The DSDs and estimated rain integral and polarimetric parameters are distinctly different for various disdrometers at similar environmental conditions. Raindrops greater than 3 mm in size are infrequent in the JWD recordings, while they are frequent in the LPM and PARSIVEL, indicating that LPM and PARSIVEL overestimate the raindrop size when the fall path deviates from nadir due to horizontal wind. The wind effect on the recorded DSD as well as estimated rain integral and polarimetric parameters are not uniform in various regions of Nivar for different disdrometers as the measuring principle and hardware processing further influence these effects. Along with the differences in measured DSD spectra, the resonance effects at X band for raindrops greater than 3 mm cause variations in the estimated polarimetric parameters between the disdrometers.</p>https://amt.copernicus.org/articles/15/6705/2022/amt-15-6705-2022.pdf |
| spellingShingle | B. Radhakrishna Raindrop size distribution (DSD) during the passage of tropical cyclone Nivar: effect of measuring principle and wind on DSDs and retrieved rain integral and polarimetric parameters from impact and laser disdrometers Atmospheric Measurement Techniques |
| title | Raindrop size distribution (DSD) during the passage of tropical cyclone Nivar: effect of measuring principle and wind on DSDs and retrieved rain integral and polarimetric parameters from impact and laser disdrometers |
| title_full | Raindrop size distribution (DSD) during the passage of tropical cyclone Nivar: effect of measuring principle and wind on DSDs and retrieved rain integral and polarimetric parameters from impact and laser disdrometers |
| title_fullStr | Raindrop size distribution (DSD) during the passage of tropical cyclone Nivar: effect of measuring principle and wind on DSDs and retrieved rain integral and polarimetric parameters from impact and laser disdrometers |
| title_full_unstemmed | Raindrop size distribution (DSD) during the passage of tropical cyclone Nivar: effect of measuring principle and wind on DSDs and retrieved rain integral and polarimetric parameters from impact and laser disdrometers |
| title_short | Raindrop size distribution (DSD) during the passage of tropical cyclone Nivar: effect of measuring principle and wind on DSDs and retrieved rain integral and polarimetric parameters from impact and laser disdrometers |
| title_sort | raindrop size distribution dsd during the passage of tropical cyclone nivar effect of measuring principle and wind on dsds and retrieved rain integral and polarimetric parameters from impact and laser disdrometers |
| url | https://amt.copernicus.org/articles/15/6705/2022/amt-15-6705-2022.pdf |
| work_keys_str_mv | AT bradhakrishna raindropsizedistributiondsdduringthepassageoftropicalcyclonenivareffectofmeasuringprincipleandwindondsdsandretrievedrainintegralandpolarimetricparametersfromimpactandlaserdisdrometers |