Scale Interaction Mechanisms in Midwest Droughts and Floods

[9627890] Arritt该项目的目标是了解和定量估计大尺度大气环流异常与与中西部夏季洪涝和干旱有关的区域水文循环的大气成分之间的联系。1979年至今，中国经历了四次大洪水和三次大干旱。在这一年里，主要研究人员将进行(1)在美国国家环境预测中心（NCEP）的全球再分析中对全球环流模式进行诊断分析，并辅以中西部地区的雨量计降水数据；(2)在NCEP分析的大尺度强迫驱动下，在气候模式下运行NCAR的MM5区域模式进行模拟。重点探讨了区域水汽通量及其与大尺度强迫的关系机制。特别注意南侧低空急流在确定水汽输送和通量散度中的作用。对于其中一个感兴趣的年份，一个重要的高分辨率数据来源将来自经过特殊处理的风廓线数据。这些研究对于理解水文循环至关重要，并将有助于实现世界气候研究计划的全球能源和水实验（GEWEX）的目标。该项目由美国国家科学基金会全球变化研究计划的水和能源：大气、植物和地球相互作用（WEAVE）倡议资助。＊＊＊

9627890 Arritt The goal of this project is to understand and estimate quantitatively the linkage between large-scale atmospheric circulation anomalies and the atmospheric component of the regional hydrological cycle associated with Midwestern summertime floods and droughts. Between 1979 and the present, there were four major flood and three major drought years. For those year, the principal investigators will carry out (1) diagnostic analyses of global circulation patterns in National Centers for Environmental Prediction (NCEP) global reanalyses, supplemented by rain-gauge precipitation data for the midwestern region and (2) simulations with NCAR's MM5 regional model, run in climate mode and driven by large-scale forcing from the NCEP analyses, focused on exploring regional water vapor fluxes and the mechanisms relating them to the large-scale forcing. Special attention will be given to the role of the southerly low-level jet in defining the water vapor transport and flux divergence. For one of the years of interest, an important additional source of high resolution data will come from specially processed wind profiler data. These studies are critical to understanding the hydrological cycle and will contribute to the goals of the Global Energy and Water Experiment (GEWEX) of the World Climate Research Program. This project is supported under NSF's Water and Energy: Atmospheric, Vegetative, and Earth Interactions (WEAVE) Initiative of the Global Change Research Program. ***