Factors affecting interannual variation in late summer rainfall in the Red River Delta of Vietnam
Abstract Based on station monthly observational statistics, the major rainfall in the Red River Delta (RRD) of Vietnam occurs in late summer (July–September) with conspicuous year-to-year variation. Using the ± 0.8 of the seasonal total rainfall standard deviation as criteria, seven wet and six dry...
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| Format: | Article |
| Language: | English |
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Springer
2023-08-01
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| Series: | Terrestrial, Atmospheric and Oceanic Sciences |
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| Online Access: | https://doi.org/10.1007/s44195-023-00045-3 |
| _version_ | 1797452402481168384 |
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| author | Duc-Tu Dinh Hai Bui-Manh Trung-Hung Le Yen-Ta Fu Cheng-Chih Lin Ming-Cheng Yen |
| author_facet | Duc-Tu Dinh Hai Bui-Manh Trung-Hung Le Yen-Ta Fu Cheng-Chih Lin Ming-Cheng Yen |
| author_sort | Duc-Tu Dinh |
| collection | DOAJ |
| description | Abstract Based on station monthly observational statistics, the major rainfall in the Red River Delta (RRD) of Vietnam occurs in late summer (July–September) with conspicuous year-to-year variation. Using the ± 0.8 of the seasonal total rainfall standard deviation as criteria, seven wet and six dry years are identified over the period 1983–2015. In addition to the 70.5% of the seasonal total rainfall contributed by the heavy rainfall days, the distinct heavy rainfall accumulation difference between wet and dry years seems to fundamentally establish these two separated extreme wet and dry groups. As revealed from further analyses, the large variability in rainfall is attributed to the influence of tropical cyclones (TCs) and 7–24- and 30–60-day intraseasonal oscillations (ISOs); in particular, the number of TCs affecting the RRD and rainfall produced by TCs are more (less) during the wet (dry) years, and the amplitudes of ISOs are also enhanced (reduced). In many cases, heavy rainfall days are induced by the combined effect of both ISOs and TCs, while some heavy rainfall events are mainly triggered by ISOs. It is found from the water vapor budget analyses that an anomalous cyclone (anticyclone) dominates over the Indochina Peninsula in wet (dry) years, resulting in more (less) water vapor being transported to the RRD, whereas the anomalous convergence (divergence) of water vapor flux leads to the maintenance of excessive (insufficient) rainfall over the RRD. However, the El Niño–Southern Oscillation (ENSO) forcing shows minor effects on the interannual variation in rainfall in the RRD. |
| first_indexed | 2024-03-09T15:08:05Z |
| format | Article |
| id | doaj.art-a8899656c65548bbaefe97ce1e3ce5e8 |
| institution | Directory Open Access Journal |
| issn | 1017-0839 2311-7680 |
| language | English |
| last_indexed | 2024-03-09T15:08:05Z |
| publishDate | 2023-08-01 |
| publisher | Springer |
| record_format | Article |
| series | Terrestrial, Atmospheric and Oceanic Sciences |
| spelling | doaj.art-a8899656c65548bbaefe97ce1e3ce5e82023-11-26T13:33:16ZengSpringerTerrestrial, Atmospheric and Oceanic Sciences1017-08392311-76802023-08-0134111410.1007/s44195-023-00045-3Factors affecting interannual variation in late summer rainfall in the Red River Delta of VietnamDuc-Tu Dinh0Hai Bui-Manh1Trung-Hung Le2Yen-Ta Fu3Cheng-Chih Lin4Ming-Cheng Yen5Department of Atmospheric Sciences, National Central UniversityDepartment of Atmospheric Sciences, National Central UniversityCenter for Hydro-Meteorological Data and Information, Vietnam Meteorological and Hydrological AdministrationDepartment of Atmospheric Sciences, National Central UniversityDepartment of Military Meteorology, Air Force Institute of TechnologyDepartment of Atmospheric Sciences, National Central UniversityAbstract Based on station monthly observational statistics, the major rainfall in the Red River Delta (RRD) of Vietnam occurs in late summer (July–September) with conspicuous year-to-year variation. Using the ± 0.8 of the seasonal total rainfall standard deviation as criteria, seven wet and six dry years are identified over the period 1983–2015. In addition to the 70.5% of the seasonal total rainfall contributed by the heavy rainfall days, the distinct heavy rainfall accumulation difference between wet and dry years seems to fundamentally establish these two separated extreme wet and dry groups. As revealed from further analyses, the large variability in rainfall is attributed to the influence of tropical cyclones (TCs) and 7–24- and 30–60-day intraseasonal oscillations (ISOs); in particular, the number of TCs affecting the RRD and rainfall produced by TCs are more (less) during the wet (dry) years, and the amplitudes of ISOs are also enhanced (reduced). In many cases, heavy rainfall days are induced by the combined effect of both ISOs and TCs, while some heavy rainfall events are mainly triggered by ISOs. It is found from the water vapor budget analyses that an anomalous cyclone (anticyclone) dominates over the Indochina Peninsula in wet (dry) years, resulting in more (less) water vapor being transported to the RRD, whereas the anomalous convergence (divergence) of water vapor flux leads to the maintenance of excessive (insufficient) rainfall over the RRD. However, the El Niño–Southern Oscillation (ENSO) forcing shows minor effects on the interannual variation in rainfall in the RRD.https://doi.org/10.1007/s44195-023-00045-3Interannual variationTropical cycloneIntraseasonal oscillationWater vapor fluxENSO |
| spellingShingle | Duc-Tu Dinh Hai Bui-Manh Trung-Hung Le Yen-Ta Fu Cheng-Chih Lin Ming-Cheng Yen Factors affecting interannual variation in late summer rainfall in the Red River Delta of Vietnam Terrestrial, Atmospheric and Oceanic Sciences Interannual variation Tropical cyclone Intraseasonal oscillation Water vapor flux ENSO |
| title | Factors affecting interannual variation in late summer rainfall in the Red River Delta of Vietnam |
| title_full | Factors affecting interannual variation in late summer rainfall in the Red River Delta of Vietnam |
| title_fullStr | Factors affecting interannual variation in late summer rainfall in the Red River Delta of Vietnam |
| title_full_unstemmed | Factors affecting interannual variation in late summer rainfall in the Red River Delta of Vietnam |
| title_short | Factors affecting interannual variation in late summer rainfall in the Red River Delta of Vietnam |
| title_sort | factors affecting interannual variation in late summer rainfall in the red river delta of vietnam |
| topic | Interannual variation Tropical cyclone Intraseasonal oscillation Water vapor flux ENSO |
| url | https://doi.org/10.1007/s44195-023-00045-3 |
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