Russian Journal of Earth Sciences Russian Journal of Earth Sciences Russian Journal of Earth Sciences 1681-1208 56640 10.2205/2022ES000816 ОРИГИНАЛЬНЫЕ СТАТЬИ ORIGINAL ARTICLES ОРИГИНАЛЬНЫЕ СТАТЬИ Wave Regime of Vietnamese Waters on the Basis of Numerical Modeling and Field Measurements Wave Regime of Vietnamese Waters on the Basis of Numerical Modeling and Field Measurements Le Mau Dinh Le Mau Dinh Власова Галина Vlasova Galina gavlasova@mail.ru Лебедев Сергей Анатольевич Lebedev Sergey Anatolievich Nguyen Tuan Van Nguyen Tuan Van Ho The Van Ho The Van Tran Binh Van Tran Binh Van Nguyen Dung Thi Thuy Nguyen Dung Thi Thuy Institute of Oceanography, Vietnam Academy of Science and Technology (IO-VAST) Вьетнам Institute of Oceanography, Vietnam Academy of Science and Technology (IO-VAST) Vietnam V. I. Il'ichev Pacific Oceanological Institute, Far Eastern Branch RAS ru V. I. Il'ichev Pacific Oceanological Institute, Far Eastern Branch RAS ru Geophysical Center, Russian Academy of Sciences, Moscow, Russia ru Geophysical Center, Russian Academy of Sciences, Moscow, Russia ru Institute of Oceanography, Vietnam Academy of Science and Technology Вьетнам Institute of Oceanography, Vietnam Academy of Science and Technology Vietnam Institute of Oceanography, Vietnam Academy of Science and Technology Вьетнам Institute of Oceanography, Vietnam Academy of Science and Technology Vietnam Institute of Oceanography, Vietnam Academy of Science and Technology Вьетнам Institute of Oceanography, Vietnam Academy of Science and Technology Vietnam Institute of Oceanography, Vietnam Academy of Science and Technology Вьетнам Institute of Oceanography, Vietnam Academy of Science and Technology Vietnam 31 12 2022 31 12 2022 22 6 1 13 08 09 2022 02 10 2022 https://rjes.ru/en/nauka/article/56640/view

This paper presents results of research of the wave regime in Vietnamese waters (South China Sea) based on the data of numerical modeling data using the WAM model (WAVE Modeling). The model domain covers the basin of the South China Sea (SCS). The bathymetry of the SCS used in the model is based on the ETOPO5 digital database. Wind parameters are based on the six-hour NCEP/NCAR reanalysis data with a resolution of ΔX = ΔY = 0.25° over the period 1979–2021. The field wave data measurements were collected by the Institute of Oceanography of Vietnam Academy of Science and Technology in the southern central Vietnamese waters in 2013. The statistical data of computed wave characteristics for the period of 43 years (1979–2021) illustrate that the main wave direction in Vietnamese waters was NE during the Northeastern (NE) monsoon, and in the opposite direction during the Southwestern (SW) monsoon. The NE monsoon wave was more dominant than that of the SW monsoon wave. Recurrence frequency (%) of significant wave height Hs >1.0 m (Hs – significant wave height is an average of 1/3 the largest of serial waves relative to average seawater level) greater than 50% covered the northeastern, central region of the SCS, and central Vietnamese coast. The wave recurrence frequency in the Gulf of Tonkin and Gulf of Thailand was <40% and <30%, respectively. The central Vietnamese coast from Ly Son Island to Phu Quy Island was the strongest affected by wave action. The recurrence frequency of the maximum significant wave height Hs >3.5 m was greater than 1.5%. The Gulf of Tonkin (Bach Long Vi Island) and the Gulf of Thailand (Tho Chu Island) were less affected by wave action than the central Vietnamese coast: the recurrence frequency of the maximum wave height (Hs>3.5 m) was less than 0.1%. Phu Quy and Con Dao Islands were more influenced by wave action during both seasons than the central coast of Vietnam.

This paper presents results of research of the wave regime in Vietnamese waters (South China Sea) based on the data of numerical modeling data using the WAM model (WAVE Modeling). The model domain covers the basin of the South China Sea (SCS). The bathymetry of the SCS used in the model is based on the ETOPO5 digital database. Wind parameters are based on the six-hour NCEP/NCAR reanalysis data with a resolution of ΔX = ΔY = 0.25° over the period 1979–2021. The field wave data measurements were collected by the Institute of Oceanography of Vietnam Academy of Science and Technology in the southern central Vietnamese waters in 2013. The statistical data of computed wave characteristics for the period of 43 years (1979–2021) illustrate that the main wave direction in Vietnamese waters was NE during the Northeastern (NE) monsoon, and in the opposite direction during the Southwestern (SW) monsoon. The NE monsoon wave was more dominant than that of the SW monsoon wave. Recurrence frequency (%) of significant wave height Hs >1.0 m (Hs – significant wave height is an average of 1/3 the largest of serial waves relative to average seawater level) greater than 50% covered the northeastern, central region of the SCS, and central Vietnamese coast. The wave recurrence frequency in the Gulf of Tonkin and Gulf of Thailand was <40% and <30%, respectively. The central Vietnamese coast from Ly Son Island to Phu Quy Island was the strongest affected by wave action. The recurrence frequency of the maximum significant wave height Hs >3.5 m was greater than 1.5%. The Gulf of Tonkin (Bach Long Vi Island) and the Gulf of Thailand (Tho Chu Island) were less affected by wave action than the central Vietnamese coast: the recurrence frequency of the maximum wave height (Hs>3.5 m) was less than 0.1%. Phu Quy and Con Dao Islands were more influenced by wave action during both seasons than the central coast of Vietnam.

 Vietnamese waters South China Sea (SCS) wave regime significant wave height monsoon WAM model Vietnamese waters South China Sea (SCS) wave regime significant wave height monsoon WAM model The authors gratefully acknowledge Dr. Gerhard Gayer (Department of Model System, Institute of Hydrophysics, GKSS, Germany) for his kind help and encouragement throughout the preparation of the WAM Cycle 4.5 model. And the grateful acknowledgment is to Vietnam Electricity (EVN) and Power Engineering Consulting JSC 2 (PECC2) for permission to publish of the observed wave data. The work was carried out within the framework of the Russian- Vietnamese cooperation FEBRAS-VAST (project numbers: VAST19-020 and QTRU02.04/19-20) and the state budget themes of POI FEBRAS (Project No:121021700341-2), and Geophysical Center of RAS, adopted by the Ministry of Science and Higher Education of the Russian Federation. This work was also supported by the Vietnam Academy of Science and Technology, grant number NVCC17.04/22-22. This paper is a contribution to celebrate the 100th Anniversary of the Institute of Oceanography, Vietnam Academy of Science and Technology and the 50th Anniversary of the V. I. Il’ichev Pacific Oceanological Institute, Far Eastern Branch, Russian Academy of Sciences. The main author, Senior Researcher Dr. Le Dinh Mau, is also thankful to the Vietnam Academy of Science and Technology for supporting his scientific activities for the year 2022. The authors gratefully acknowledge Dr. Gerhard Gayer (Department of Model System, Institute of Hydrophysics, GKSS, Germany) for his kind help and encouragement throughout the preparation of the WAM Cycle 4.5 model. And the grateful acknowledgment is to Vietnam Electricity (EVN) and Power Engineering Consulting JSC 2 (PECC2) for permission to publish of the observed wave data. The work was carried out within the framework of the Russian- Vietnamese cooperation FEBRAS-VAST (project numbers: VAST19-020 and QTRU02.04/19-20) and the state budget themes of POI FEBRAS (Project No:121021700341-2), and Geophysical Center of RAS, adopted by the Ministry of Science and Higher Education of the Russian Federation. This work was also supported by the Vietnam Academy of Science and Technology, grant number NVCC17.04/22-22. This paper is a contribution to celebrate the 100th Anniversary of the Institute of Oceanography, Vietnam Academy of Science and Technology and the 50th Anniversary of the V. I. Il’ichev Pacific Oceanological Institute, Far Eastern Branch, Russian Academy of Sciences. The main author, Senior Researcher Dr. Le Dinh Mau, is also thankful to the Vietnam Academy of Science and Technology for supporting his scientific activities for the year 2022.

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