Mixing and Transport in the Upper Troposphere and Lower Stratosphere

Northwest Research Associates, Incorporated, Seattle WA

Investigators

Abstract

The upper troposphere/lower stratosphere (UTLS) is a transit region, the dynamics of which is still insufficiently understood. This research seeks to address a range of questions concerning the dynamics of the UTLS, the resulting impacts on UTLS tracers (H20 and O3), and dynamical forcing by the two tracers on the UTLS. A simple, yet dynamically consistent model will be used to generate flows and to isolate and understand associated transport processes and mixing regimes. An underlying theme is the search for an accurate description of the small-scale structures resulting from typical mixing processes in the UTLS region. Intellectual merit. The PI will improve our fundamental understanding of mixing and transport processes in the UTLS region. Particular attention will be paid to the mixing and transport of radiatively and chemically important trace species, stratosphere-troposphere exchange, the transport of water vapor from the tropics to the extratropics, and transport by monsoon circulations. Completion of this work will offer new insights into: 1. Mixing processes and the resulting fine-scale constituent distributions in the UTLS region, and 2. Further understanding of climate sensitivity to dynamics of UTLS. Broader impacts. The issues addressed by this research are fundamental to our understanding of the mixing and transport processes in the UTLS on a range of spatial and temporal scales, an area of much recent research. A new flux parameterization may be developed. This work is closely related to key initiatives of the Stratospheric Processes And their Role in Climate (SPARC) project, a component of the World Climate Research Program.