Theoretical and Numerical Investigations of the Earth's Midlatitude Tropopause

University Of Chicago, Chicago IL

Investigators

Abstract

The project will investigate the dynamical mechanisms maintaining tropopause height and its permeability in the extratropical latitudes. Understanding the formation, maintenance, and kinematics of the midlatitude tropopause remains a core, challenging problem in dynamic meteorology. Recent interest in its dynamic permeability stems from its considerable impact on transport of chemical constituents, including ozone and water vapor, between the troposphere and stratosphere. Dr. Nakamura (U of Chicago) will investigate the problem both theoretically and numerically. Numerical calculations with quasi-geostrophic and general circulation models will expand the theoretical analysis of the advection-diffusion equation to more realistic scenarios, including one involving penetration of the tropopause by the eddy potential vorticity fluxes. The project will advance theoretical understanding of the dynamical interaction of the troposphere and stratosphere, and should provide separate estimates of the stratosphere-to-troposphere, and troposphere-to-stratosphere mass transfers, which will improve modeling and prediction of cross-tropopause transports of trace gases and substances.