Modeling of Tropospheric Chemistry

Harvard University, Cambridge MA

Investigators

Abstract

This project is an effort to use 3-D numerical simulations to improve our understanding of tropospheric chemistry. The project will focus on two issues: 1) the chemical evolution of the extratropical northern hemisphere in winter-spring, and 2) the sources and atmospheric distribution of acetone. The first of these involves participation in the Tropospheric Ozone Production about the Spring Equinox (TOPSE) aircraft field campaign. This campaign will examine the chemistry controlling the budgets of NOx, HOx, and ozone at high latitudes during the springtime onset of photochemistry, with the goal of understanding the origin of the springtime ozone maximum in that region. The second topic involves improving our understanding of acetone and its role as a source of HOx and peroxyacetyl nitrate (PAN) in the upper troposphere. New information from field and laboratory studies will be used to develop a global 3-D simulation of the global acetone budget. The model results will be evaluated using results from recent aircraft campaigns (SONEX, PEM-Tropics B). This project will utilize the Harvard-GEOS model of tropospheric chemistry, driven by assimilated meteorological observations from the NASA Data Assimilation Office.