Introduction

Overview e outputs of this research have been reported annually via the RIMS system. is report serves as an update and nal report. e focus of our DOE BES funded project is on the importance of heterogeneous reactions in the troposphere. e primary objectives of our study were to: (i) Evaluate the extent to which heterogeneous chemistry aects the photochemical oxidant cycle, particularly, sources and sinks of tropospheric ozone; and (ii) Conduct laboratory studies on heterogeneous reactions involving NOy, O3 and VOCs on aerosol surfaces. ese objectives were pursued through a multidisciplinary approach that combines modeling and laboratory components as discussed in more detail below. In addition, in response to the reconguring of the Atmospheric Science Program

to focus on aerosol radiative forcing of climate, we also began to investigate the radiative properties of atmospheric aerosol.