Studying On The Interannual Variations And Generative Mechanism Of Upwelling Along The Guangdong East Coast

Upwelling is a marine dynamic process coupled with the ecological process of marine organisms,which is widely distributed in the coastal areas with high global marine productivity.Under the background of global warming,the annual change trend of coastal upwelling has become a research hotspot of global climate change in recent years.The study of upwelling is of great significance to the improvement of marine ecological environment,the development of green marine resources and the sustainable development of marine economy.Based on the data of temperature,chlorophyll concentration,wind field in 2002-2016 and marine fishing volume in Guangdong Province in 2010-2018,this paper reviews the research progress of upwelling in the world since 1970 s,studies the inter annual variation trend of upwelling intensity and center position along the east coast of Guangdong Province,and discusses the relationship between upwelling intensity and wind speed,marine fishing volume and upwelling intensity.The results show that in the past 15 years,the intensity of upwelling along the east coast of Guangdong Province has been strengthened,and the maximum probability of the center of upwelling intensity is 23.6 ° N-23.7 ° N,and there is a trend of northward movement.Coastal wind plays an important role in the annual change of upwelling.Excluding the damage of fishing structure and other factors,the correlation between the marine catch and upwelling in Guangdong Province is very high,and the correlation coefficient is-0.81.In this paper,the sensitivity experiment of upwelling sea area in the East Guangdong region of the South China Sea is also carried out by using the three-dimensional temperature field simulated by POM Model and the climatic data.The results show that the upwelling in the coastal area of eastern Guangdong is not mainly caused by wind.There is cold water along the northern coast of the South China Sea,which flows slowly eastward due to the action of ocean current.However,there is a barrier of reefs in the coastal area of eastern Guangdong,where the cold water will gather in the area of 116 ° E-118 ° E Upwelling nearby forms upwelling;upwelling along the east coast of Guangdong in the north of the South China Sea is not caused by the wind site,but the wind site has certain impact on its upwelling.When the wind speed is less than a certain value,the upwelling generated by the wind site is covered by the warm current brought by the reverse wind,resulting in a smaller upwelling intensity,and when the wind speed is higher than a certain value(twice),the upwelling generated by the wind site The current intensity can be counterbalanced with the warm current to maintain its own intensity.In this study,the center of the fishing area along the eastern Guangdong coast in the northern South China Sea was determined.The center of the strongest upwelling is 23.6o-23.7o north latitude,and there is a tendency to shift northward year by year.For a sustained growth trend;when the summer southwest monsoon is weakened by other factors,the fishery production in the upwelling area along the east coast of Guangdong will not be seriously affected,because even in the absence of wind,there is an upwelling in the study area.In addition,the mechanism of upwelling,research methods,biological impact and artificial application are summarized and analyzed in order to provide some basis and new ideas for the research of upwelling and marine resources in China.