Work on the chemistry version of the Weather Research and Forecasting Model (WRF-Chem) is progressing. The current development version features online coupling between the meteorology and chemistry, to account for the integrated effects of both. To date, however, emissions estimates--with the notable exception of biogenic emissions--have been provided to the model using historical data not linked to the integrated model solution. This does not account for the meteorologically dependent portions of point, area, and mobile emissions sources, and will be crucial as the model progresses towards operational status.

In this paper, the implementation of an online emissions modeling approach, using the Sparse-Matrix Kernel Emissions Processing System (SMOKE), will be described. SMOKE is being used as the emissions processing/modeling system of choice in a number of present-day air quality modeling systems, and is considered the state-of-the-art currently available. Modifications/enhancements to SMOKE required for online integration into WRF will be discussed, and early results, comparing an online-emissions with offline-emissions WRF-Chem case study, will be presented.