Critical Study on the An_??_ular-momentum-transfer Method and Vorticity-transfer Method in the Investi_??_ation of Zonal Circulation of the Atmosphere

[摘要] A comparative and critical study of the angular-momentum-transfer and vorticity-transfer methods in the investigation of zonal circulation of the atmosphere is given. The essential difference between the two methods is that the fluctuating variations of atmospheric pressure in the west-east direction, which certainly exist in a turbulent field of flow, are ignored in the former method, while in the latter the variations are taken into account. According to the former method, the displaced particle moving towards the pole gains the west component of wind speed and the displaced particle moving towards the equator loses the west component of wind speed. While, according to the latter method, the displaced particle moving north or southward usually gains the west component of wind speed. Very high velocities will result when a mass is moved horizontally from a given latitude towards the pole or equator under conservation of its angular momentum, while quite reasonable velocities will be given when a mass is moved horizontally under conservation of its absolute vorticity. Such an essential difference can be readily seen from Tables l•a and l•b.

[学科分类] 大气科学