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，审查未来几十年北美西部天气和水文气候统计数据的预期变化。北美西部已经经历了重大的气候和水文气候变化。模型预测，在未来几十年里，气候变暖将继续，北美西南部和南部平原将变得更加干旱，而北部落基山脉和平原将变得更加湿润。此外，预计降水将变得更加强烈，所有时间尺度上的变率将更强，降水、土壤湿度和河流的季节循环将发生显著变化。虽然这些预估的变化将对水资源、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，模式对辐射驱动的水文气候变化的模拟数据与实际变化并不相符。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率所掩盖。这项工作将涉及三个相互交织的努力：1)分析政策和管理决策，以确定对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)评估在决策分析中确定与管理相关的那些气候特征的长期变化如何在日常方面发挥作用；水文气候信息在季风区水资源和生态系统管理以及平原生态系统管理问题中的应用。将考虑由于自然变率和强迫变化引起的近期气候演变，包括风暴频率和地点的变化、干旱期的长度、极端湿润或干旱年、季节性等。将分析观测记录和再分析，包括20世纪再分析，以及参与耦合模式比对项目5的模式。长期的控制运行和上一千年的模拟将使我们能够对水文气候的自然变率范围进行前所未有的评估，而每日数据的存档将使我们能够开创性地评估气候变化对近期天气的影响。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；研究工作将考虑大尺度气候特征和短期天气，以及这些特征如何在时间和空间上变化，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.