The effects of land use in meteorological modeling: implications for assessment of future air quality scenarios

In recent years, there has been an increased use of prognostic meteorological models to assess current and future air quality related problems. Often, these meteorological models are applied in their forecasting mode with current land use/land cover patterns and data assimilation techniques to generate historical meteorological data for use in air quality models. In this study, we examined the sensitivity of land use/land cover on the predicted meteorological fields, and the implications for examining air quality in a future year. A community-based mesoscale meteorological model (MM5-Version 1) was applied to the northeastern US urban corridor under two scenarios, one with the existing land use/land cover (base case), and the second reflecting a hypothetical change in about 40% of the base case urban grid cells to deciduous forest. A comparison of the two meteorological fields reveals substantial localized differences in surface temperature and zonal wind speeds. These findings suggest reevaluation of the practice of using historical meteorological fields to assess future air quality, especially if one expects large changes in land use patterns.