Storm Morphology and the Influence of Orography on Lake-Effect Precipitation

湖泊效应降水既是一个重大的天气灾害，也是美国五大湖等地的经济驱动力。 在过去的几十年里，对湖泊效应降雪的预测已经有所改善，但在湖泊效应事件期间，对降雪分布可能产生重大影响的具体过程仍然存在悬而未决的问题。 这项研究奖将解决的一个因素是地形在确定湖泊效应降水影响方面的作用。 地形如何影响湖效应降水的普遍理解是，附近的丘陵或山脉提供的升力导致对流的活跃，从而导致降水。 然而，最近的研究发现，情况并非总是如此，在某些地形区域，风暴深度和对流强度会减少。 该项目将通过分析两个不同地区的观测结果来解决地形和湖泊效应降水问题：纽约安大略湖下游的Tug Hill高原，在2013-14年安大略冬季湖泊效应系统（OWLeS）活动期间大量使用仪器，以及日本本州岛，由于日本海的长期影响，本州岛接收了大量的湖泊效应雪。 将进行分析和建模工作，以利用地理，地形和湖泊效应风暴特征的鲜明对比，以扩大对湖泊效应降水的地形影响的理解。 该奖项的影响应该是改善湖泊效应地区的天气和气候预报，以及加强与从事类似问题研究的国际科学家的合作。 该奖项的结果将通过多种方式传播，包括经常访问的博客网站和通过K-12外联。 多名研究生将参与研究，确保培养下一代科学家。 该奖项将通过对纽约塔格山高原和日本本州岛的湖泊效应风暴的观测分析和数值模拟，提高对地形如何影响湖泊效应降雪的理解。 这两个地区有大量的湖泊或海洋效应降雪，但产生降水增强的机制几乎没有比较。 该项目的总体目标是提高对丘陵、山脉和高地地区对湖泊效应降水影响的认识和预测。 三个主要的科学问题将被解决：1）地形的存在如何影响的启动，分布和强度的湖泊效应降水？ 2)在湖效应风暴期间，控制地形比例（低地与高地）的关键机制是什么？ 3)地形比例如何随环境条件、云过程、湖泊形状和大小以及地形尺度和几何形状而变化？

Lake-effect precipitation is both a significant weather hazard and an economic driver for locations like the US Great Lakes. Forecasts of lake-effect snow have improved over the past few decades, but there are still outstanding questions about specific processes that can have a major impact on the distribution of snowfall during a lake-effect event. One factor that will be addressed by this research award is the role of topography in determining the impact of lake-effect precipitation. The prevailing understanding of how topography affects lake-effect precipitation is that the lift provided by nearby hills or mountains results in an invigoration of the convection and therefore the precipitation. However, recent research has discovered that this is not always the case, and that there is a decrease in storm depth and convective vigor in certain topographic areas. This project will address the issue of topography and lake-effect precipitation through analysis of observations from two distinct areas: the Tug Hill plateau downstream of Lake Ontario in New York, which was heavily instrumented during the 2013-14 Ontario Winter Lake-effect Systems (OWLeS) campaign, and Honshu Island in Japan which receives copious amounts of lake-effect snow due to the long fetch over the Sea of Japan. Analysis and modeling efforts will be conducted to take advantage of the stark contrasts in geographic, topographic, and lake-effect storm characteristics to broaden the understanding of orographic influences on lake-effect precipitation. The impact of this award should be improved weather and climate forecasts in lake-effect regions as well as enhanced collaboration with international scientists working on similar issues. The results of the award would be disseminated through multiple means including a frequently visited blog site and through K-12 outreach. Multiple graduate students would be involved in the research, ensuring training of the next generation of scientists. This award will improve understanding of how orography affects lake-effect snowfall through observational analysis and numerical modeling of lake-effect storms on the Tug Hill Plateau of New York and Honshu Island in Japan. These two regions have prolific amounts of lake or ocean-effect snowfall, but there has been little comparison of the mechanisms that produce the precipitation enhancement. The overall goal of the project is to advance knowledge and prediction of the influence of hills, mountains, and upland regions on lake-effect precipitation. Three main scientific questions would be addressed: 1) How does the presence of topography affect the initiation, distribution, and intensity of lake-effect precipitation? 2) What are the key mechanisms controlling the orographic ratio (lowland vs upland) during lake-effect storms? 3) How does the orographic ratio vary with environmental conditions, cloud processes, lake shape and size, and terrain scale and geometry?