Study On The Relationship Between Red Tide And Weather In Dongtou Coastal Sea Of Zhejiang Province

Red Tide is a complicated and serious disaster which impacts on the marine environment. Meteorological factors are important induced conditions for red tide disasters.Causes of red tide prevention and early warning and forecasting related has been the focus and difficulty of red tide disaster research, first the red tide historical Case and meteorological data of 2007-2012 in Dongtou coast were analyzed and studied, concluded that the Dongtou coastal sea is a high incidence of red tide disasterthe whivh was determined by the distinct location, the island topography, coastal aquaculture industry as well as climatic conditions. And red tides occur mainly in 5-9 months time, the vast majority occur in 5-6 months each year, while the occurrence of red tide in coastal development in recent years steadily increasing trend.Based on the spatial and temporal distribution of red tide and the impact analysis for meteorological elements, concluded that the variation of meteorological elements when red tide breakout in Dongtou coastal sea,the changes in atmospheric circulation and the Important weather system with guidance for use of meteorological conditions forecast for the next red tide.Secondly, based on the influence of the three red tide one example of the historical process analysis, gain the characteristics of red tide in Dongtou coastal sea influenced by atmospheric circulation occurrence:the subtropical high dominated in 500 hPa height, warm-wet air maintain in 850 hPa height, ground maintain weak easterly or southerly wind for a long time, and this weather situation is favorable to the development of red tide. In addition,in the spring and summer seasons alternately, at the junction of westerly and easterly, the atmospheric circulation in a steady state or move less, which provided a favorable atmosphere for persistenting the outbreak of red tide. The meteorological elements to adjust and changes in atmospheric circulation have a significant impact on the development of red tides, the status of red tide will change when the fierce changes in atmospheric circulation or the impact by a large-scale system,moreover the red tide which breakout in different seasons, the dominant meteorological elements also different, It is worth mentioning that the precipitation and wind play a "early warning" role in the process of the red tide.By regression analysis, found that the air temperature, the average air pressure and relative humidity and red tide algae concentrations were positively correlated, while precipitation, sunshine, wind speed and red tide algae concentration was negatively correlated. The average wind speed and the concentration of red tide algae maximum correlation coefficient, followed by the sunshine, and the third is the daily precipitation, all correlation coefficients were significant test by a=0.05 reliability. While using multiple regression analysis, an algae concentration as the dependent variable, the meteorological elements for multiple linear regression equation independent variables and predict the effect of test, forecast values and live relatively close to the value obtained on the whole.It has a certain reference value. Finally,it is able to establish a suitable meteorology forecasting model and service programs for the red tide of Dongtou coastal sea.