Theoretical and Numerical Investigations of the Earth's Midlatitude Tropopause

该项目将研究维持温带纬向对流层顶高度及其渗透率的动力机制。了解中纬度对流层顶的形成、维持和运动仍然是动力气象学的一个核心、具有挑战性的问题。最近对其动态渗透性的兴趣源于它对化学成分（包括臭氧和水蒸气）在对流层和平流层之间的输送的相当大的影响。中村博士（芝加哥大学）将从理论上和数值上研究这个问题。准地转和环流模式的数值计算将把平流扩散方程的理论分析扩展到更现实的情景，包括涡位涡通量穿透对流层顶的情景。该项目将促进对对流层和平流层动力学相互作用的理论理解，并应提供平流层到对流层和对流层到平流层的质量传递的单独估计，这将改进对流层顶间微量气体和物质输送的建模和预测。

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.