when the tropical easterly flow decreases, the center position of depression moves northward, the strength of depression increases and the zonal width of depression widens.
当热带东风气流减弱时,低压中心位置偏北,低压强度增强,低压纬向宽度变大;
the weak shear of easterly flow has no influence on depression zonal width, however, it has a certain influence on strength and center position of depression.