正压地转流的空间不稳定  

Spatial Instability of Barotropic Geostrophic Flow

作　　者：林一骅 LIN Yihua(State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics(LASG),Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029;College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049)

机构地区：[1]中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室(LASG),北京100029 [2]中国科学院大学地球与行星科学学院,北京100049

出　　处：《大气科学》2024年第3期837-842,共6页Chinese Journal of Atmospheric Sciences

基　　金：国家自然科学基金项目42275057、42230403、42075008。

摘　　要：与时间不稳定一样,空间不稳定也是地球流体中扰动发生发展的重要机制。基于标准模方法,研究了正压地转流对于小扰动的空间不稳定问题,并得到发生空间不稳定的必要条件。该必要条件指出,若正压地转流可能发生空间不稳定,其位涡对于纬度的偏微商与小扰动相对于该地转流的相速必须在某些纬度带异号。在附加适当的限制的情况下,空间不稳定与时间不稳定满足相同的必要条件,即Rayleigh–Kuo定理和Fjørtoft定理。Like temporal instability,spatial instability also plays an important role for the development and evolution of disturbances in geophysical fluids.Based on the normal mode method,the spatial instability of the barotropic geostrophic flow is investigated.The necessary condition for spatial instability of a barotropic geostrophic base flow with respect to a given small disturbances is the partial differential quotient of the potential vorticity of the base flow with respect to the latitude has the opposite sign as that of the phase velocity of the disturbance.Under certain conditions,like the classical temporal instability theory,the same criteria as the necessary conditions are provided,namely the Rayleigh-Kuo theorem and the Fjørtoft theorem.

关 键 词：地转流动 正压 空间不稳定 必要条件 

分 类 号：P401[天文地球—大气物理学与大气环境]