Nghiên cứu động học và cấu trúc khối nước tại vùng biển thềm lục địa Nam Việt Nam vào mùa Hè năm 2010

• Ngôn ngữ: vie
• Ký hiệu phân loại: 551.4609597 Geomorphology and hydrosphere
• Thông tin xuất bản: Hợp tác quốc tế trong điều tra, nghiên cứu tài nguyên và môi trường biển, 2011
• Mô tả vật lý: 183-191
• Bộ sưu tập: Metadata
• ID: 504786

Tóm tắt

The paper presents results of first survey implemented in. summer of 2010 in accordance with the Sub-project 2 of Vietnam-Russia collaboration on marine meteorological, hydrological and dynamical investigation the hydrographic observations. The survey included observations of physical and ecoloKical parameters with a Koal to characterize summer conditions in the continental shelf waters of Khanh Hoa province, southern Vietnam. Based on these observations a vertical structure and spatial distribution of main oceanographic parameters and structure of currents and frontal zones off central Vietnam were analyzed In Summer of 2010 an anomalous anticyclonic circulation and warm water pool was observed off southern coast of Vietnam which is different from the situation of previous years. This dynamic system caused convergence of warm surface water at the coastal area instead of cold water upwelling zone usually occurred there in previous summer seasons. Water temperature was higher and exceeded 30°C at the surface. Vertical profiles of other oceanographic parameters demonstrated baroclinic structure over the shelf with two or three layers of interleaving water masses. An interesting result was an observation of very high turbidity bottom layer of 20-30 m thick located at the outer shelf area which probqbly corresponds to advection of coastal water with high content of suspended matter or high productivity area over the shelf which leads to formation of nepheloid layer. The measurements of currents had confirmed a strong diurnal tide impact on shelf water dynamics off central Vietnam. Maximum currents were observed up to 50 cm/s in surface layer and more then 30 cm/s at the bottom. Vertical structure of tidal flow had opposite directions in surface and bottom layer during the tidal phase shift. A soliton like feature was observed propagating in Nha Trang Bay and increasing currents speed by two times and thus enhancing vertical mixing which may have important ecological consequences.