说明：  运用Crank-Nicholson差分格式，模拟不同初始风场、垂向涡动系数和风应力拖曳系数下，Ekman风海流随时间的变化情况。
(The crank Nicholson difference scheme is used to simulate the change of Ekman wind current with time under different initial wind field, vertical eddy coefficient and wind stress drag coefficient.)