Application of Himawari-8 Data to Enteromorpha Prolifera Dynamically Monitoring in the Yellow Sea

As a new generation geostationary meteorological satellite, Himawari-8 can provide measurements dynamically monitoring of Enteromorpha prolifera, with its high temporal-spatial resolution. According to the normalized differential vegetation index NDVI, by studying reflection characteristics of enteromorpha, a method using Himawari-8 data is proposed for enteromorpha information detection, drift speed and intensity estimation. Using the above methods, the outbreak processes of enteromorpha prolifera in the Yellow Sea from May to July in 2016 are monitored including the appearing time, location, areas, intensity, range of influence, drift path and drift speed. Results show that the enteromorpha are detected firstly on 19 May 2016 in the Yellow Sea and areas are relatively small. It outbreaks in mid and late June with its continuous growth, and areas, range of influence and intensity all reach the maximum in this period. The enteromorpha enters recession period in early July near the coast of Shandong Province, the Yellow Sea, such as Qingdao, Yantai, Weihai and so on.The calculation shows that enteromorpha intensity changes with time, and multi-temporal enteromorpha intensity are accumulated into enteromorpha intensity synthetic product. The multi-temporal enteromorpha intensity synthetic product shows that enteromorpha intensity covers more in the central Yellow Sea and the east of Yantai waters, and less in initial position. The moving path of enteromorpha from appearance to disappearance shows that the drift path of enteromorpha is from the southeast open sea to the northwest offshore, and the average daily drift speed changes constantly.Dynamic changes of enteromorpha are closely related to the environmental hydro meteorological conditions, such as temperature, wind speed and direction. The suitable temperature is the basis for enteromorpha's growth and development. In late May, enteromorpha growth are detected near the northern coast of Jiangsu Province firstly, where the temperature is stably 20℃. And then in early June, enteromorpha area increases rapidly with the increasing temperature, and then outbreaks in mid-June when the temperature reaches 20℃ in east of Shandong Peninsula sea. In early July, the average temperature of the Yellow Sea is above 25℃, making the enteromorpha decay and disappear gradually. It shows that dominant wind direction is the main driving force of enteromorpha drift, the calculation shows that enteromorpha drifts northward with large and steady south wind from May to July in 2016, and finally arrive in Weihai coast, and the moving direction is in line with the wind.