Bowden Jared H, Terando Adam J, Misra Vasu, Wootten Adrienne, Bhardwaj Amit, Boyles Ryan, Gould William, Collazo Jaime A, Spero Tanya L
Department of Applied Ecology, North Carolina State University, Raleigh, North Carolina, USA.
Southeast Climate Adaptation Science Center, US Geological Survey, Raleigh, North Carolina, USA.
Int J Climatol. 2021 Feb 17;41(2):1305-1327. doi: 10.1002/joc.6810.
The Weather Research and Forecasting (WRF) model and a combination of the Regional Spectral Model (RSM) and the Japanese Meteorological Agency Non-Hydrostatic Model (NHM) were used to dynamically downscale selected CMIP5 global climate models to provide 2-km projections with hourly model output for Puerto Rico and the U.S. Virgin Islands. Two 20-year time slices were downscaled for historical (1986-2005) and future (2041-2060) periods following RCP8.5. Projected changes to mean and extreme temperature and precipitation were quantified for Holdridge life zones within Puerto Rico and for the U.S. Virgin Islands. The evaluation reveals a persistent cold bias for all islands in the U.S. Caribbean, a dry bias across Puerto Rico, and a wet bias on the windward side of mountains within the U.S. Virgin Islands. Despite these biases, model simulations show a robust drying pattern for all islands that is generally larger for Puerto Rico (25% annual rainfall reduction for some life zones) than the U.S. Virgin Islands (12% island average). The largest precipitation reductions are found during the more convectively active afternoon and evening hours. Within Puerto Rico, the model uncertainty increases for the wetter life zones, especially for precipitation. Across the life zones, both models project unprecedented maximum and minimum temperatures that may exceed 200 days annually above the historical baseline with only small changes to the frequency of extreme rainfall. By contrast, in the U.S. Virgin Islands, there is no consensus on the location of the largest drying relative to the windward and leeward side of the islands. However, the models project the largest increases in maximum temperature on the southern side of St. Croix and in higher elevations of St. Thomas and St. John.
利用天气研究与预报（WRF）模型以及区域谱模型（RSM）和日本气象厅非静力模型（NHM）的组合，对选定的CMIP5全球气候模型进行动力降尺度，以提供波多黎各和美属维尔京群岛每小时模型输出的2公里分辨率预测。按照RCP8.5，对历史时期（1986 - 2005年）和未来时期（2041 - 2060年）的两个20年时间切片进行了降尺度。对波多黎各和美属维尔京群岛的霍德里奇生物带的平均温度、极端温度和降水的预测变化进行了量化。评估结果显示，美国加勒比地区所有岛屿存在持续的冷偏差，波多黎各全境存在干旱偏差，美属维尔京群岛山脉迎风面存在湿润偏差。尽管存在这些偏差，但模型模拟显示所有岛屿都有明显的干旱趋势，波多黎各（某些生物带年降雨量减少25%）的干旱趋势通常比美属维尔京群岛（全岛平均减少12%）更为显著。最大降水量减少出现在对流活动更活跃的下午和傍晚时段。在波多黎各，较湿润的生物带模型不确定性增加，尤其是降水方面。在所有生物带中，两个模型都预测了前所未有的最高和最低温度，每年可能有超过200天高于历史基线，而极端降雨频率变化很小。相比之下，在美属维尔京群岛，关于相对于岛屿迎风面和背风面最大干旱区域的位置没有一致结论。然而，模型预测圣克罗伊岛南部以及圣托马斯岛和圣约翰岛较高海拔地区的最高温度增幅最大。
