Deposition of pollutants in high elevation ecosystems due to interception of cloud droplets by vegetation can contribute significantly to the overall deposition budgets in these areas.  Prediction of this phenomenon by regional scale meteorological and chemical transport models is challenging as the typical 12km x 12 km grid may not resolve the clouds and complex terrain.  Finer horizontal and vertical resolution is often needed.  Research is underway in the Atmospheric Modeling and Analysis Division to incorporate this important process into the CMAQ modeling system.