North American Spring Tropospheric Ozone Maximum Using a Stretched-Grid Chemistry and Transport Model (SG-CTM)

University Of Maryland, College Park, College Park MD

Investigators

Abstract

Tropospheric ozone measurements at many sites in the northern mid- to high-latitudes show a spring time maximum. This feature is the focus of the Tropospheric Ozone Production about the Spring Equinox (TOPSE) experiment, which is being carried out in spring 2000 above mid-high latitude North America. Several factors may contribute to the maximum including: 1) increased stratosphere-troposphere exchange (STE) during the spring, 2) increased concentrations of ozone precursors and/or ozone itself during the late winter, and 3) an imbalance favoring chemical production of ozone versus chemical destruction of ozone in the early spring. The primary objective of this project is to investigate the role of STE and long-range transport in the evolution of trace gas distributions over the TOPSE study region during the winter to spring transition. The primary tool that will be used is the University of Maryland Stretched-Grid Chemistry and Transport Model (SG-CTM) driven by data from the Stretched-Grid Goddard Earth Observing System Data Assimilation System (GEOS SG-DAS). The SG-CTM will be used to solve constituent continuity equations for the distributions of several radionucleides (10Be, 7Be, 222Rn, and 210Pb).