Collaborative Research: EAGER--Dual-Polarimetric Doppler-On-Wheels Observations of Long Lake-Axis-Parallel Lake-effect Storms over Lakes Erie and Ontario

湖泊效应暴风雪是冬季降水和五大湖地区高影响天气的主要来源。这些风暴通常表现出两种截然不同的形态之一：风平行卷环流，其中拉长的降水特征优先面向盛行的低层气流（以及伴随的垂直风切变），而长湖轴平行（LLAP）降水带通常更强烈，首选湖中位置。llap型风暴在东部五大湖（即伊利湖和安大略湖）更为常见，但对其的研究远远少于风平行带。这个探索性项目将部署一个新的极化单“车轮多普勒”（DOW）移动雷达来观测llap型雪带。这些数据将在2010年至2011年冬季的五周时间内收集，并将由这些波段内外的移动降雨探空仪导出的热力学剖面进行补充。这项工作的智力价值在于改进了强llap型湖泊效应雪带中尺度形态、演变和降水机制的规范。鉴于首次在冷季环境中部署极化DOW，人们的注意力将集中在对最近升级的平台的极化数量和水流星分类输出的关键评估上。通过支持主要本科学术机构的研究，以及通过一组本科生直接参与收集和分析这一探索性数据集，将产生更广泛的影响。结果将通过会议发言和正式出版物传播。

Lake-effect snowstorms are a key source of wintertime precipitation and high-impact weather over the Great Lakes region. These storms typically evince one of two contrasting morphologies: Wind-parallel roll circulations in which elongated precipitation features are preferentially oriented along the prevailing low-level flow (and accompanying vertical wind shear), versus long lake-axis parallel (LLAP) precipitation bands that are typically more intense with a preferred mid-lake location. LLAP-type storms are more common over the Eastern Great Lakes (viz. Erie and Ontario), but have been studied far less than wind-parallel bands. This exploratory project will field a newly polarized single "Doppler on Wheels" (DOW) mobile radar to observe LLAP-type snowbands. These data, which will be collected during a five-week period during winter 2010-11, will be complemented by mobile rawinsonde-derived thermodynamic profiles obtained both within and external to these bands.The intellectual merit of this effort centers on improved specification of the mesoscale morphology, evolution and precipitation mechanisms within intense LLAP-type lake effect snowbands. In view of this first-ever deployment of a polarized DOW in a cool-season setting, attention will be directed to a critical evaluation of polarization quantities and hydrometeor classification output from this recently upgraded platform.Broader impacts will accrue through support of research at a primarily undergraduate academic institution and via direct involvement of a group of undergraduate students in both the collection and analysis of this exploratory dataset. Results will be disseminated via conference presentations and formal publications.