ABSTRACT

Carbon monoxide (CO) is an important component of the atmospheric chemical system and has both natural and anthropogenic sources. Three-dimensional atmospheric chemical model simulations using inventory-based bottom-up estimates of CO sources have shown that human activities contribute substantially to CO concentrations on regional and global scales. However, significant uncertainties persist in regional estimates of anthropogenic CO sources derived using bottom-up approaches, leading to corresponding uncertainties in the predicted human impacts on the atmospheric CO distribution. The focus of this talk will be on deriving regional CO source estimates using an alternative approach. The methodology involves the use of a global atmospheric chemical transport and measurements of atmospheric concentrations of CO in an inverse modeling framework to derive geographically and sectorally disaggregated, top-down estimates of CO sources. Specific questions that will be addressed include (i) the extent to which atmospheric CO measurements provide constraints on regional CO sources, and (ii) the extent to which the derived top-down regional source estimates are consistent with the corresponding bottom-up estimates.