This proposal addresses the identified ROSES 2007 priority areas of air quality and public health. Specifically, in the air quality area the aspects of emissions inventories and forecasting are addressed in our proposal. These improved inventories will also support more accurate assessments of human and ecosystem health. This work builds upon the established unique research strengths of the research team in emission inventory development, chemical transport modeling, and satellite observations. These aspects will be combined to provide top-down constraints on emissions. The integration of these efforts requires the use of chemical transport models to provide inverse modeling analyses. Top-down emissions have been combined with a bottom-up emission inventory to develop an improved a posteriori estimate of global and regional NOx emissions in basic research applications. However these studies were not designed as a systematic framework to ultimately provide an operational approach to rapid update of emissions, nor did they contain an active bottom-up emission estimate component, which is necessary to reflect and interpret emission changes (including those due to changes in legislation, technology, and economic factors). In this proposed research these activities, enhanced by closer interactions with the satellite community and informed by more recent participation in NASA field experiments (including INTEX A and B), will be utilized to develop and test a systematic analysis framework to provide rapid updates of emission inventories (i.e., updated on an annual basis). The impact of these improved inventories will be tested in air quality forecasting and human health assessment applications. Through this proposed research a systematic analysis framework to provide rapid updates of emission inventories will be developed and demonstrated in US and Asian applications, and will support several important international activities, including the EU task Force on Hemispheric Transport of Pollutants, among others.