Climate Impacts of Historical Land Cover Change in Trinidad W.I

There is a considerable need to examine regional climate change for small island developing states of the Caribbean region. While many studies have documented the climatological importance of land use/land cover change (LULCC) in general, there has been little focus on individual Caribbean islands. To fill this void, we explore the climatological effects of land cover change in Trinidad, West Indies, utilizing a regional climate model (RCM). For the Caribbean, a lack of extensive land surface area and limited spatial and temporal weather data coverage has hindered capacity to perform thorough, high-resolution weather and climate modeling studies at the island scale. During the preceding decade, the improvement of high-resolution RCMs and computing power advancements have made small scale climate research a realistic possibility. Such advances in technology are particularly important when studying limited areas to ensure the model appropriately resolves small scale features and surface characteristics, which directly affect the local atmospheric patterns experienced by an individual island.

For this study, we employ the Weather Research and Forecasting (WRF) Model version 3.6.1, to assess the climatological effects of LULCC in Trinidad, West Indies. We performed a series of experiments for a below average dry season and an above average rainy season, 2003 and 2006, respectively. These simulations utilized combinations of two WRF cloud micro-physics parameterization schemes (WSM 3-class scheme and WDM 6-class scheme), two land cover datasets (Moderate Resolution Imaging Spectroradiometer (MODIS) and United States Forest Service (USFS)), and two sea surface temperature datasets (National Centers for Environmental Prediction (NCEP) Final Operational Global Analysis and NCEP Real Time Global Sea Surface Temperature (RTGSST)), for each season. The output from these simulations was evaluated against data from available temperature and rainfall observation stations, and TRMM precipitation data, in order to select an optimal model configuration and to conduct further sensitivity experiments to LULCC. Upon selecting the simulation that best reproduced the seasonal meteorology, we performed a sensitivity experiment to gauge the climatological effects of historical land cover change. In this final simulation, we replaced the land cover of the island with its potential pre-settlement land cover: broadleaf evergreen forest. Results indicate considerable impact on the surface energy budget, with implications for near-surface temperature and moisture variables, resulting from the historical landscape change of Trinidad. These results demonstrate the critical nature of incorporating land-based adaptation and mitigation strategies in addition to reducing greenhouse gas emissions, and highlight the capability of RCMs to facilitate more detailed island-scale studies that can be utilized in local decision making that benefit society and the environment.