Collaborative Research: The Kinematics, Microphysics and Dynamics of Long-fetch Lake-effect Systems in Ontario Winter Lake-effect Systems (OWLeS)

该合同是安大略省冬季（OW）湖泊效应系统（LeS）现场项目的关键部分，该项目将于2013年12月至2014年1月进行。OWLeS将侧重于两条互补的研究线，每条线都追踪美国五大湖地区的首选风态和相应的冬季风暴组织的独特中尺度模式。由该小组领导的活动将集中在所谓的“长风暴”事件上，在这种情况下，低层风大约与安大略湖的长轴平行。OWLeS期间将使用的观测设备包括怀俄明大学空中国王仪表飞机、CSWR多普勒轮式（DOW）移动雷达、多个移动雨测系统、米勒斯维尔大学剖面系统、UAH移动综合剖面系统以及各种其他可部署的地面测量系统。这些研究人员认为，对LeS降雪量和内陆范围的预测仍然很差，部分原因是逆风行星边界层结构的细尺度变化以及云微物理、动力和地表过程的不充分表征。为了解决这些缺点，本研究的知识价值将来自于对以下问题的更好理解：1)长时间强降雪如何在湖的下风增强和演变，在那里长时间的强降雪率特别有影响；2)云和动力过程如何促进云通电和闪电，如在长时间LeS强降水单体中偶尔观察到的；3)移动dow和国家气象局运行的WSR-88D雷达分别利用X波段和s波段的双偏振（以及在特定地区，双多普勒）雷达测量如何揭示LeS中详细的降水过程。通过与现场飞机测量的详细比较，评估双偏振粒子识别和定量降水估计（QPE）算法将扩展遥感观测在这种独特的冷季环境中的效用。更广泛的影响将包括为大量本科生和研究生提供内场活动策划、动手数据收集和数据分析的经验。初级和高级主要研究人员的适当组合将促进既定和复杂的项目设计和观测方法的交流，并促进适合冬季恶劣天气条件的改进的实地观测技术。推广工作将扩大到K-12学生和在附近高等院校就读的大学生。鉴于湖效应降雪对美国五大湖沿岸人口稠密地区的公共安全和经济活动的重大影响，提高对湖效应系统的理解应该促进改进模型和预测技术，以满足长期的社会需求。

This award is one key segment of a larger effort centered on the Ontario Winter (OW) Lake-effect Systems (LeS) field project, to be conducted December 2013-January 2014. OWLeS will focus on two complementary lines of research, each tracing to a preferred wind regime over the U.S. Great lakes region and corresponding distinct mesoscale mode of winter storm organization. Activities led by this group will focus on so-called "long-fetch" storm events, for which low-level winds are aligned approximately parallel to Lake Ontario's long axis. Observational assets to be employed during OWLeS include the University of Wyoming King Air instrumented aircraft, the CSWR Doppler on Wheels (DOW) mobile radars, multiple mobile rawinsounding systems, the Millersville University Profiling System, the UAH Mobile Integrated Profiling System, and a variety of other deployable surface measurement systems. These researchers contend that predictions of the amounts and inland extent of LeS snowfall remain poor, due in part to fine-scale variations in upwind planetary boundary layer structure and poor representation of cloud microphysical, dynamical, and surface processes. To address these shortcomings, the intellectual merits of this research will derive from improved understanding of: 1) How long-fetch LeS intensify and evolve downwind of the lake, where prolonged heavy snowfall rates are particularly impactful; 2) how cloud and dynamical processes may contribute to cloud electrification and to lightning, as occasionally observed in long-fetch LeS heavy precipitation cells; and 3) how dual-polarimetric (and in select regions, dual-Doppler) radar measurements at X- and S-band wavelengths as utilized by mobile-DOW and operational National Weather Service WSR-88D radars, respectively, may reveal detailed precipitation processes in LeS. Through detailed comparisons with in-situ aircraft measurements, evaluations dual-polarimetric particle identification and quantitative precipitation estimate (QPE) algorithms will extend the utility of remote-sensing observations in this unique cool-season environment.Broader impacts will include experience infield campaign planning, hands-on data collection and data analysis for a notably large number of undergraduate as well as graduate students. A desirable mix of junior and senior principal investigators will facilitate exchange of established and complex project design and observing methodologies, and foster improved field observing techniques tailored to severe winter weather conditions. Outreach efforts will extend to K-12 students and college students enrolled at nearby institutes of higher learning. Given the significant impacts of lake effect snowfall on public safety and economic activity along the populous shores of the U.S. Great Lakes, improved understanding of lake-effect systems should foster refined models and forecasting techniques that will address a longer-term societal need.