Dual-Doppler radar analysis of a near-shore line-shaped convective system on 27 July 2011, Korea: a case study
In the summer rainy season, the Korean Peninsula is frequently influenced by severe weather phenomena such as floods and rain-induced landslides. A band-shaped precipitation system associated with unstable atmospheric conditions occurred over northwest Korea on 27 July 2011. This precipitation syste...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Stockholm University Press
2014-05-01
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| Series: | Tellus: Series A, Dynamic Meteorology and Oceanography |
| Subjects: | |
| Online Access: | http://www.tellusa.net/index.php/tellusa/article/download/23453/pdf_1 |
| _version_ | 1817971209197846528 |
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| author | Jung-Tae Lee Dong-In Lee Cheol-Hwan You Hiroshi Uyeda Yu-Chieng Liou In-Seong Han |
| author_facet | Jung-Tae Lee Dong-In Lee Cheol-Hwan You Hiroshi Uyeda Yu-Chieng Liou In-Seong Han |
| author_sort | Jung-Tae Lee |
| collection | DOAJ |
| description | In the summer rainy season, the Korean Peninsula is frequently influenced by severe weather phenomena such as floods and rain-induced landslides. A band-shaped precipitation system associated with unstable atmospheric conditions occurred over northwest Korea on 27 July 2011. This precipitation system produced heavy rainfall over the Seoul metropolitan area, which received over 80 mm h−1 of rainfall and suffered 70 weather-related fatalities. To investigate the precipitation system, we used diverse meteorological data of environmental condition and estimated three-dimensional wind field from dual-Doppler radar measurements of vertical air motion. Environmental conditions included high equivalent potential temperature (θe) of over 355 K at low levels, and low θe of under 330 K at middle levels, causing vertical instability. Furthermore, a pressure trough was located to the northwest of Korea, favouring the development of the band-shaped precipitation system. The tip of the band-shaped precipitation system was made up of line-shaped convective systems (LSCSs) that caused flooding and landslides, and the LSCSs were continuously enhanced by merging between new cells and the pre-existing cell. The position of merging moved from the coast to offshore areas and influenced the positioning of the regions of enhanced convection. In turn, this affected the roughness of the convective cell and the internal structure of the enhanced convective regions. Onshore, the convective area was higher than in offshore areas because of strong convergence (≤−4×10−4 s−1) at low levels caused by friction over land. The strong convergence generated strong updraft (≥4 m s−1) that influenced the height of the convective area. The convective region offshore was wider than that onshore because of weak convergence (≥−2.2×10−4 s−1) at low levels. Updraft in offshore areas was weak (≤3 m s−1) compared with onshore, resulting in a lower and wider convective area. Spatial variations in surface roughness result in different structural features and profiles of divergence within LSCSs, even if they originate in the same convective region. |
| first_indexed | 2024-04-13T20:43:43Z |
| format | Article |
| id | doaj.art-a7f707866e23477cbcf8226ec39c2c82 |
| institution | Directory Open Access Journal |
| issn | 1600-0870 |
| language | English |
| last_indexed | 2024-04-13T20:43:43Z |
| publishDate | 2014-05-01 |
| publisher | Stockholm University Press |
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| series | Tellus: Series A, Dynamic Meteorology and Oceanography |
| spelling | doaj.art-a7f707866e23477cbcf8226ec39c2c822022-12-22T02:30:45ZengStockholm University PressTellus: Series A, Dynamic Meteorology and Oceanography1600-08702014-05-0166011510.3402/tellusa.v66.2345323453Dual-Doppler radar analysis of a near-shore line-shaped convective system on 27 July 2011, Korea: a case studyJung-Tae Lee0Dong-In Lee1Cheol-Hwan You2Hiroshi Uyeda3Yu-Chieng Liou4In-Seong Han5 Department of Environmental Atmospheric Sciences, Pukyong National University, 599-1 Daeyeon 3-Dong, Namgu, Busan 608-737, Korea Department of Environmental Atmospheric Sciences, Pukyong National University, 599-1 Daeyeon 3-Dong, Namgu, Busan 608-737, Korea Atmospheric Environmental Research Institute, Pukyong National University, 599-1 Daeyeon 3-Dong, Namgu, Busan 608-737, Korea Hydrospheric Atmospheric Research Center, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan Department of Atmospheric Sciences, National Central University, 320 Jhongli City, Taiwan Division of Fishery and Ocean Information, National Fisheries Research & Development Institute, Gijang-Eup, Gijang-Gun, Busan 619-705, KoreaIn the summer rainy season, the Korean Peninsula is frequently influenced by severe weather phenomena such as floods and rain-induced landslides. A band-shaped precipitation system associated with unstable atmospheric conditions occurred over northwest Korea on 27 July 2011. This precipitation system produced heavy rainfall over the Seoul metropolitan area, which received over 80 mm h−1 of rainfall and suffered 70 weather-related fatalities. To investigate the precipitation system, we used diverse meteorological data of environmental condition and estimated three-dimensional wind field from dual-Doppler radar measurements of vertical air motion. Environmental conditions included high equivalent potential temperature (θe) of over 355 K at low levels, and low θe of under 330 K at middle levels, causing vertical instability. Furthermore, a pressure trough was located to the northwest of Korea, favouring the development of the band-shaped precipitation system. The tip of the band-shaped precipitation system was made up of line-shaped convective systems (LSCSs) that caused flooding and landslides, and the LSCSs were continuously enhanced by merging between new cells and the pre-existing cell. The position of merging moved from the coast to offshore areas and influenced the positioning of the regions of enhanced convection. In turn, this affected the roughness of the convective cell and the internal structure of the enhanced convective regions. Onshore, the convective area was higher than in offshore areas because of strong convergence (≤−4×10−4 s−1) at low levels caused by friction over land. The strong convergence generated strong updraft (≥4 m s−1) that influenced the height of the convective area. The convective region offshore was wider than that onshore because of weak convergence (≥−2.2×10−4 s−1) at low levels. Updraft in offshore areas was weak (≤3 m s−1) compared with onshore, resulting in a lower and wider convective area. Spatial variations in surface roughness result in different structural features and profiles of divergence within LSCSs, even if they originate in the same convective region.http://www.tellusa.net/index.php/tellusa/article/download/23453/pdf_1line-shaped convective systemback-buildinglow-level convergencenearshore |
| spellingShingle | Jung-Tae Lee Dong-In Lee Cheol-Hwan You Hiroshi Uyeda Yu-Chieng Liou In-Seong Han Dual-Doppler radar analysis of a near-shore line-shaped convective system on 27 July 2011, Korea: a case study Tellus: Series A, Dynamic Meteorology and Oceanography line-shaped convective system back-building low-level convergence nearshore |
| title | Dual-Doppler radar analysis of a near-shore line-shaped convective system on 27 July 2011, Korea: a case study |
| title_full | Dual-Doppler radar analysis of a near-shore line-shaped convective system on 27 July 2011, Korea: a case study |
| title_fullStr | Dual-Doppler radar analysis of a near-shore line-shaped convective system on 27 July 2011, Korea: a case study |
| title_full_unstemmed | Dual-Doppler radar analysis of a near-shore line-shaped convective system on 27 July 2011, Korea: a case study |
| title_short | Dual-Doppler radar analysis of a near-shore line-shaped convective system on 27 July 2011, Korea: a case study |
| title_sort | dual doppler radar analysis of a near shore line shaped convective system on 27 july 2011 korea a case study |
| topic | line-shaped convective system back-building low-level convergence nearshore |
| url | http://www.tellusa.net/index.php/tellusa/article/download/23453/pdf_1 |
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