Aspects of Potential Vorticity Fluxes: Climatology and Impermeability

作者：Egger Joseph^*; Hoinka Klaus Peter; Spengler Thomas

来源：Journal of the Atmospheric Sciences, 2015, 72(8): 3257-3267.

DOI：10.1175/JAS-D-14-0196.1

• Atmospheric circulation
• Conservation equations
• Dynamics
• Large-scale motions
• Momentum
• Potential vorticity

Some aspects of the dynamics of generalized potential vorticity (PV) density P = delta are discussed with the main emphasis on P fluxes, where (a) is absolute vorticity and is a scalar. The impermeability theorem claims that there is no net P flux across a surface. Various forms of the flux are presented that mostly cross surfaces. As these fluxes are as dynamically relevant as the one chosen for the theorem, P fluxes through a surface element are inherently multivalued and there is no best choice on physical grounds. Nevertheless, the net P flux is unique for closed surfaces. This point is illustrated by P integrals over the volume between the earth's surface and an isentropic surface. Reanalysis data are used to present mean advective and some nonadvective P fluxes for = in height coordinates. The extratropical tropopause appears to be supported by advective P fluxes. A satisfactorily closed P budget cannot, however, be presented.

• 出版日期2015-8