Contemporary Variability, Future Changes and Human Dimensions of Snowpack Water Resources Over the Western United States

小行星9634329 一个研究小组将数据分析、遥感、建模和全球变化的人的方面的技能结合起来，将对美国西部在当代和未来可能的气候状态下积雪水资源的可变性和可持续性进行综合评估。 重点将放在科罗拉多和哥伦比亚盆地和次盆地。 将使用混合数据集评估当代变率，该数据集包括来自SNOTEL（SNOwTELemperature）站点和天气报告站的每日雪水当量（SWE）、温度和降水记录以及来自被动微波亮度温度的SWE。 结合国家气象中心（NMC）的“再分析”大气场，我们将首先专注于建立大规模和区域之间的关系流通和积雪的季节性积累/融化。 随后将分析观测记录中的极端情况以及西南偏东变率与遥相关型之间的联系，强调区域对厄尔尼诺-南方涛动强迫的反应。 这些调查还将利用NMC中期预报（MRF）模型的集合预报，该模型由观测到的和理想化的海表面温度演变所推动。 我们的实证和建模研究利用了循环“降尺度”，即点或区域变量（例如，SNOTEL站点的SWE（子流域平均值）通过基于主成分分析的与大气环流模式的频率/持续性的经验关系与环流相关。 在对当代变率进行研究之后，将把环流降尺度传递函数应用于至少两个不同的大气环流模式（GCM）的2xCO 2输出。 这种技术充分利用了当今的大气环流模式，通过使用大尺度环流来提供气候变化情景，模式再现得相当好，同时避免了模拟点表面变量的不确定性。 在类似于上述的诊断研究之后，重建的每日温度、SWE和2xCO 2情景的降水将与融雪径流模型相结合，在一系列区域研究中评估融雪径流未来的潜在变化。 利用上述调查的信息沿着其他现有数据，将检查科罗拉多和哥伦比亚流域的不同水管理系统，因为它们与SWE的季节性国际变化和全球变化条件有关。 目标是改进与城乡交界处沃茨资源管理最相关的时间和空间尺度上的预测，并改进那些适合于了解水文变异性的预测。 这些研究将侧重于：1）用户之间水资源分配的灵活性，以应对水资源可用性的年际变化和潜在变化; 2）系统产出（农业、娱乐、电力、水质）对可能的极端气候变化、气候事件序列和气候变化的脆弱性。

9634329 Serreze A research team combining skills in data analysis, remote sensing, modeling and the human dimensions of global change will conduct an integrated assessment of the variability and sustainability of snowpack water resources over the western United States under contemporary and possible future climate states. Emphasis will be placed on the Colorado and Columbia basins and sub-basins. Contemporary variability will be assessed using blended data sets incorporating daily snow water equivalent (SWE), temperature and precipitation records from SNOTEL (SNOwTELemetry) sites and synoptic reporting stations as well as SWE derived from passive microwave brightness temperatures. In conjunction with National Meteorological Center (NMC) 'reanalysis' atmospheric fields, we will first focus on establishing large-scale and regional relationships between circulation and the seasonal accumulation/melt of the snowpack. This will be followed by analyses of extremes in the observed record and linkages between SWE variability and teleconnection patterns, emphasizing regional responses to El-Nino Southern Oscillation (ENSO) forcings. These investigations will also utilize ensemble forecasts from a version of NMC's Medium Range Forecast (MRF) model, forced by observed and idealized evolutions of sea surface temperature. Our empirical and modeling studies make use of circulation 'downscaling', whereby point or regional variables (e.g., SWE from SNOTEL sites average for sub-basins) are related to circulation through empirical relationships with the frequency/persistence of atmospheric circulation patterns based on principal component analyses. Following studies of contemporary variability, the circulation downscaling transfer functions will be applied to 2xCO2 output from at least two different general circulation models (GCMs). This technique makes the best use of today's GCMs to provide climate change scenarios through use of the large-scale circulation, which the models reproduce fairly well, while avoiding the uncertainties modeled point surface variables. Following diagnostic studies similar to those outlined above, reconstructed daily temperature, SWE and precipitation from the 2xCO2 scenarios will be coupled with a snowmelt runoff model, providing assessment of potential future changes in snowmelt runoff in a series of regional studies. Using information from the above investigations along with other existing data, different systems of water administration in the Colorado and Columbia basins will be examined as they relate to seasonal to international variations in SWE and conditions of global change. The objective is to improve predictions on the time and space scales most relevant to the management of waters resources at urban-rural interfaces and those appropriate to understanding hydrologic variability. These studies will focus on: 1) flexibility of water allocation among users in response to interannual variability and potential changes in water availability and 2) vulnerability of system outputs (agriculture, recreation, power, water quality) to possible extremes of climate variations, sequences of climate events and climate change.