Simulated impacts of anthropogenic land-cover change on the mesoscale climate of the Florida Peninsula

Highly detailed datasets that represent natural and current land cover on the Florida peninsula were implemented in the Regional Atmospheric Modeling System to simulate the impacts of anthropogenic land-cover change on the mesoscale climate of this region. When current land cover was used in simulations of three recent July--August periods, daytime maximum temperatures were generally warmer, and regional-scale rainfall was decreased by 10--12%. The results provide new evidence of a physical-dynamical mechanism that directly links the regional-scale rainfall decrease with the impacts of land-cover changes on the mesoscale nature of the sea-breeze circulations. The simulated differences in rainfall and daily maximum temperature that result from land-cover change are consistent with long-term trends derived from an analysis of observational data.; The two land-cover datasets were also applied to simulate three recent (and climatologically rare) agriculturally damaging freeze events in south Florida. Detailed examination of one event reveals that the specification wetlands increased the heat capacity of the land surface and supplied a persistent water vapor flux, thereby altogether preventing the development of freezing conditions at a location where crop losses totaled US {dollar}300M. With current land cover (i.e., agriculture), subfreezing temperatures developed and persisted for five hours.; The results presented in this work suggest that anthropogenic land-cover changes have significantly impacted several aspects of the mesoscale climate of the Florida Peninsula. The results of this study also support previous studies in concluding that perturbations introduced to the climate system through anthropogenic land-cover change are physically and socioeconomically significant.