Global Budgets of Atmospheric Trace Gases

Harvard University, Cambridge MA

Investigators

Abstract

This project involves 3-dimensional chemical transport model simulations and analysis of atmospheric observations, focusing on the global budgets of several important atmospheric trace gases. Specific activities will focus on: (1) the global budget of mercury including sources, exchange with surface reservoirs, and chemical transformations, with the goal of improving our understanding of anthropogenic influences and source-receptor relationships; (2) the budgets of methanol, acetone, and acetaldehyde, and their implications for atmospheric chemistry, making use of measurements from recent and ongoing aircraft campaigns (ICARTT, MILAGRO, INTEX-B); and (3) the global budget of carbonyl sulfide (OCS) with focus on quantifying source and sink processes, and assessing the anthropogenic influence. The project will involve a combination of forward and inverse modeling in the analysis of atmospheric observations. Forward model simulations based on best a priori estimates of sources and sinks will be compared to observed concentration statistics to test the basic understanding of processes. Inverse modeling will be used in the analyses of mercury and OCS budgets to optimize the magnitudes of individual budget terms on the basis of the constraints offered by atmospheric observations. This project will provide opportunities for graduate students to obtain training in the methods of atmospheric chemistry modeling. The results of the study will benefit society by improving the fundamental understanding of important atmospheric processes. The results on mercury will be of benefit because of the health-related concerns.