The research documented in this manuscript demonstrates that Oklahoma's winter wheat belt has a significant impact on the near-surface, mesoscale environment during growth and after harvest. Differences in near-surface atmospheric variables across the wheat belt and its adjacent lands are documented using the following methods: (1) observational analyses of monthly averaged daily statistics (e.g., daily maximum or minimum) during Crop Year 2000, (2) observational analyses of daily averages and instantaneous measurements for several case study days during Crop Year 2000, (3) statistical analyses of daily statistics from 1994 through 2001, and (4) numerical simulations of case study days during Crop Year 2000 that applied two different land uses over the wheat belt region for comparison.

Analysis results from these different methods are consistent and establish a convincing case that the crop belt modifies both the mesoscale climatology and, on many days, the daily weather of Oklahoma. Consequently, it is imperative that mesoscale forecasts, whether produced objectively or subjectively, account for the vegetation-land-air interactions that occur across western Oklahoma and, presumably, across other crop regions in the U.S. and around the globe.