Statistical Analysis of Cold Eddy Characteristics in Northwest Pacific Ocean
In the Northern Hemisphere,cyclonic eddies form upwelling currents that cause cooler seawater at the bottom to surge to the surface and mix with warmer seawater at the surface,causing the temperature of the surface seawater to drop and the height of the central sea surface to drop.In this paper,statistical analysis of the cold eddies data set is carried out to explore the spatio-temporal variation of the cold eddies.It is found that the amount of cold eddies generated and dissipated shows irregularity and consistency in spatial distribution,and shows strong seasonality in time,more in winter and less in summer.The amount of cold eddies generated in autumn and winter is greater than the amount of eddies dissipated,but the opposite is true in spring and summer.The amount of generation decreases with the extension of life,and the average velocity shows greater instability with the shortening of life.More than 76.5%of the cold eddies move to the west,and the cold eddies moving to the east tend to be generated in the sea area north of 30°N.By calculating the rotation velocity and amplitude of the cold eddies,it is found that their high values correspond to the latitude of the high values of the EKE.