Design of a North American Backbone Atmospheric Observing System

Major sources and sinks of trace gases create concentration patterns in the atmosphere that can provide a quantitative measure of the sources and sinks. The goal of the atmospheric observing system for North America is to provide strong atmospheric constraints on sources on a regional scale (1000 km and larger) so that the response of the natural systems to climate anomalies and human management can be quantified and followed. The climatology of the air flow over North America at different altitudes provides guidance for the initial selection of sampling locations. Early goals are to provide an initial rudimentary estimate for the total net source or sink for the United States, and new data to help improve formulations of atmospheric transport and mixing used in inverse models. Results from planned intensive campaigns will help define required sampling density in space and time.