Earth and Environmental Sciences, Lehigh University, 1 W Packer Avenue, Bethlehem, PA, 18015, United States.
Sci Rep. 2016 Jul 18;6:29962. doi: 10.1038/srep29962.
Characterizing precipitation seasonality and variability in the face of future uncertainty is important for a well-informed climate change adaptation strategy. Using the Colwell index of predictability and monthly normalized precipitation data from the Coupled Model Intercomparison Project Phase 5 (CMIP5) multi-model ensembles, this study identifies spatial hotspots of changes in precipitation predictability in the United States under various climate scenarios. Over the historic period (1950-2005), the recurrent pattern of precipitation is highly predictable in the East and along the coastal Northwest, and is less so in the arid Southwest. Comparing the future (2040-2095) to the historic period, larger changes in precipitation predictability are observed under Representative Concentration Pathways (RCP) 8.5 than those under RCP 4.5. Finally, there are region-specific hotspots of future changes in precipitation predictability, and these hotspots often coincide with regions of little projected change in total precipitation, with exceptions along the wetter East and parts of the drier central West. Therefore, decision-makers are advised to not rely on future total precipitation as an indicator of water resources. Changes in precipitation predictability and the subsequent changes on seasonality and variability are equally, if not more, important factors to be included in future regional environmental assessment.
在面对未来的不确定性时，描述降水的季节性和变率特征对于制定明智的气候变化适应策略非常重要。本研究利用可预测性科威特定律指数和耦合模式比较计划第五阶段（CMIP5）多模式集合的月标准化降水数据，确定了在美国各种气候情景下，降水可预测性变化的空间热点。在历史时期（1950-2005 年），东部和沿西北海岸的降水具有高度可预测性，而干旱的西南部则不然。与历史时期相比，在代表浓度路径（RCP）8.5 下，未来（2040-2095 年）的降水可预测性变化大于 RCP 4.5。最后，降水可预测性的未来变化存在特定区域的热点，这些热点通常与总降水预计变化较小的区域重合，但在较湿润的东部和较干燥的中西部部分地区除外。因此，决策者不应仅依靠未来的总降水量作为水资源的指标。降水可预测性的变化以及随后的季节性和变率变化同样重要，甚至更为重要，应将其纳入未来的区域环境评估中。
