The Madden-Julian Oscillation and Predictability of Extreme Precipitation in the United States

AbstractResearch在这个补助金检查极端降水事件的可预测性的变化（即降雨或降雪超过气候分布的第90百分位数）与不同阶段的马登-朱利安振荡（MJO）。 MJO是在印度洋上空形成并缓慢向东传播到赤道中太平洋的大尺度降水和环流异常。 初步工作的PI根据他们以前的NSF拨款表明，美国大陆（CONUS）的极端降水预报的第一周和第二周的预测的技能在整个MJO生命周期的过程中变化，CONUS陆地面积的一部分，其中存在显着的技能是最大的阶段1，2，7和8的MJO。 这项资助下的工作探讨了在全球范围内使用天气研究和预报（WRF）模型的后报集成的技能差异。 这项工作检查的预测技能，并试图了解的动力机制，通过该阶段和幅度的MJO影响极端降水forecasting.The研究的技能，通过更好的长期天气预报与MJO行为的经济和社会价值有更广泛的影响。 初步工作估计的经济价值，在上述MJO阶段，这是最大的沿着东部的海底和中西部的极端降水预报的技能的改进。此外，该项目还资助了一名研究生和博士后研究员，从而促进了大气科学劳动力的发展。 该奖项的主要研究人员还参与了一些推广活动，包括为高中生举办的为期六周的夏季研究计划，以及在国家地理的地理意识周期间举办的研讨会。

AbstractResearch under this grant examines changes in the predictability of extreme precipitation events (i.e. rainfall or snowfall exceeding the 90th percentile of the climatological distribution) associated with different phases of the Madden-Julian Oscillation (MJO). The MJO is a large-scale precipitation and circulation anomaly which forms over the Indian Ocean and propagates slowly eastward to the central equatorial Pacific. Preliminary work by the PIs under their previous NSF grant shows that the skill of extreme precipitation forecasts over the continental US (CONUS) for week one and week two of the forecast varies over the course of the MJO lifecycle, the portion of CONUS land area in which significant skill exists being largest in phases 1, 2, 7, and 8 of the MJO. Work under this grant explores the skill differences using hindcast integrations of the Weather Research and Forecasting (WRF) model on a global domain. The work examines the skill of forecasts and also seeks to understand the dynamical mechanisms through which the phase and amplitude of the MJO affect the skill of extreme precipitation forecasts.The research has broader impacts through the economic and social value of better long-range weather forecasts associated with MJO behavior. Preliminary work estimates the economic value of improvements in the skill of extreme precipitation forecasts in the above MJO phases, which is largest along the eastern seabord and in the midwest. In addition, the project supports a graduate student and postdoctoral researcher, thereby contributing to the development of the workforce in atmospheric science. The Principal Investigators for this award are also engaged in a number of outreach activities, including a six-week summer research program for high school students, and seminars conducted during National Geographic's Geography Awareness Week.