Collaborative Research: EaSM2--Linking Near Term Future Changes in Weather and Hydroclimate in Western North America to Adaptation for Ecosystem and Water Management

该项目将从水和生态系统管理需要的角度审查北美西部未来几十年天气和水气候统计数据的预期变化。北美西部已经经历了显著的气候和水气候变化。模型预测，在接下来的几十年里，全球变暖将继续下去，北美西南部和南部平原将变得更加干旱，落基山脉和平原北部将变得更加湿润。此外，预计降水将变得更加强烈，所有时间尺度上的变异性都会更强，降水、土壤水分和径流的季节周期将发生重大变化。虽然这些预计的变化将对水资源、农业、牧场、野生动物管理和自然生态系统(包括森林、火灾等)产生严重影响，但必须指出的是，辐射驱动的水气候变化模型对数据的模拟与实际变化并不十分一致。这可能是因为模型是错误的，或者辐射驱动的变化被强大的自然变异性所掩盖。这项工作将涉及三个相互交织的工作：1)分析政策和管理决策，以确定生态系统和水管理的需求，以及如何将科学转化为满足这些需求；2)评估在决策分析中被确定为与管理相关的气候特征的长期变化，在逐日、逐月和逐年天气方面发挥作用；3)将水文气候信息应用于季风区水资源和生态系统管理以及平原的生态系统管理问题。将考虑由于自然变化和强迫变化造成的近期气候演变，包括风暴频率和位置、干旱持续时间、极端潮湿或干旱年份、季节性等的变化。将分析观测记录和再分析，包括20世纪再分析，以及参与耦合模式国际比较项目5的模型。长期控制运行和过去千年的模拟将允许对水文气候的自然变化范围进行前所未有的评估，每日数据的归档将使对气候变化如何影响天气的开创性评估成为可能。重点地理区域从太平洋海岸延伸到大平原，从加拿大延伸到墨西哥；研究工作将考虑大范围气候特征和短期天气，以及这些特征可能如何在时间和空间上发生变化，影响未来的景观和生态区域。

This project will examine anticipated changes in the statistics of weather and hydroclimate over western North America in coming decades from the point of view of needs in the management of water and ecosystems. Western North America is already experiencing significant climate and hydroclimate change. Models project that over the next few decades warming will continue, southwestern North America and the southern Plains will become more arid and the northern Rockies and Plains will become modestly more humid. Additionally precipitation is projected to become more intense, variability on all timescales stronger and significant shifts to occur in the seasonal cycles of precipitation, soil moisture and streamflow. While these projected changes will have serious implications for water resources, agriculture, rangelands, wildlife management and natural ecosystems including forests, fire, etc. it must be noted that the model simulations of radiatively-driven hydroclimate change to data are not in close accord with actual change. This could be because the models are wrong or radiatively-driven change is being obscured by potent natural variability. The work will involve three interwoven efforts: 1) analysis of policy and management decisions to identify needs for ecosystem and water management, and how to translate science to meet those needs, 2) an assessment of how long term changes in those climate features identified as management-relevant in the decision analysis, play out in terms of day-to-day, month-to-month and year-to-year weather and 3) application of hydroclimate information to problems in water resources and ecosystem management in the monsoon region and ecosystem management in the Plains. Evolution of near term climate due to both natural variability and forced change will be considered, including changes in frequencies and locations of storms, lengths of dry spells, extreme wet or dry years, seasonality etc. Observational records and Reanalyses, including the 20th Century Reanalysis, will be analyzed as well as the models participating in Coupled Model Intercomparison Project 5. Long control runs and last millennium simulations will allow an unprecedented assessment of the range of natural variability of hydroclimate and archiving of daily data will allow a pioneering assessment of how climate change impacts weather in the near term future. The geographic area of focus extends from the Pacific coast to the Great Plains and from Canada into Mexico; the research effort will consider large-scale climate features and short term weather and how these features may shift in time and space, influencing the landscapes and ecoregions of the future.