Orographic Influences on Lake-Effect Precipitation

地形对湖泊效应降水的影响

• 批准号: 0938611
• 负责人: W. James Steenburgh
• 金额: $ 47.11万
• 依托单位: University of Utah
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-06-15 至 2014-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0938611&HistoricalAwards=false
• 关键词: Orographic; Influences; Lake; Effect; Precipitation

Orography has a dramatic influence on lake-effect snowstorms, not only in regions with major mountain barriers such as the Great Salt Lake Basin of northern Utah, but also in the eastern United States and Canada where more modest relief is found around the Great Lakes. For example, over the Tug Hill Plateau of northern New York, which lies downstream of Lake Ontario, annual snowfall increases 25-50 mm for every 100 m rise in elevation and storm-total accumulations have reached 360 cm in extreme lake-effect events. Orography also modifies the morphology of lake-effect snowstorms by altering the relationship between the large-scale flow and the development of precipitation structures such as broad-area precipitation shields and shoreline bands. Knowledge of lake-orographic precipitation processes is important not only for weather prediction, but also applications in hydrology, ecology, and geomorphology.The primary goal of the project is to improve understanding of lake-orographic precipitation processes and their influence on the weather and climate of lake-effect regions. Key questions to be investigated include: (1) to what extent does orography modify the morphology of lake-effect snowstorms, (2) which orographic processes and phenomena are responsible for these modifications, and (3) to what degree do lake-orographic precipitation processes contribute to the hydroclimate of lake effect regions? These questions will be addressed in a three year research program that examines two regions where there are strong orographic influences on lake-effect precipitation. The first is the Great Salt Lake basin of northern Utah where the Wasatch Mountains and other ranges rise up to 2000 m above lake level. The second is the Tug Hill Plateau of northern New York, which provides a broad upland region 400-500 m above Lake Ontario. The research will produce a synthesis of results from a radar-based climatology, a field campaign, and numerical modeling.Intellectual merit: The research will advance knowledge and understanding of the physical processes that control lake-effect and orographic precipitation and, in turn, the influence of these processes on the hydrometeorology of lake-effect regions. Efforts to establish a relationship between the large-scale flow and lake-effect morphology have proven challenging, with previous workers specifically identifying the need to better understand the role of orography in altering structural transition zones. Project results will address this need.Broader impacts: The project addresses the societal need to improve weather and climate prediction in lake-effect regions. Other broader impacts include:(1) the infusion of research findings into undergraduate and graduate courses, training courses, and web-based educational modules, (2) the mentoring of two graduate students and the broadening of the participation of women in NSF-sponsored programs, and (3) the enhancement of public scientific understanding through collaborations with an NSF GK-12 graduate fellowship program that involve graduate student researchers in K-12 classrooms to teach discovery based environmental science in Salt Lake City school districts.Further, this research program will likely engender broad scientific interest in other allied research communities such as hydrology, ecology, and geomorphology.

地形对湖泊效应暴风雪有着巨大的影响，不仅在有主要山脉屏障的地区，如北方犹他州的大盐湖盆地，而且在美国东部和加拿大，五大湖周围的地形也较为平缓。例如，在安大略下游的北方纽约的塔格山高原上，海拔每上升100米，年降雪量增加25-50毫米，在极端的湖泊效应事件中，风暴总累积量达到360厘米。地形也改变了湖泊效应暴风雪的形态，通过改变大规模的流动和降水结构，如大面积的降水盾和海岸带的发展之间的关系。湖泊-地形降水过程的知识不仅对天气预报很重要，而且对水文学、生态学和地貌学的应用也很重要。该项目的主要目标是提高对湖泊-地形降水过程及其对湖泊效应区天气和气候影响的认识。要研究的关键问题包括：（1）地形在多大程度上改变了湖泊效应暴风雪的形态，（2）哪些地形过程和现象是这些修改的原因，（3）湖泊地形降水过程在多大程度上有助于湖泊效应地区的水文气候？这些问题将在一个为期三年的研究计划，检查两个地区，有强烈的地形影响湖效应降水。第一个是犹他州北方的大盐湖盆地，那里的瓦萨奇山脉和其他山脉高出湖平面2000米。第二个是北方纽约的塔格山高原，它提供了一个广阔的高地地区，海拔400-500米，高于安大略湖。这项研究将产生一个综合的结果，从雷达为基础的气候学，实地活动，和数值modeling.Intellectual优点：这项研究将推进知识和理解的物理过程，控制湖泊效应和地形降水，反过来，这些过程对水文气象的湖泊效应地区的影响。努力建立大规模流动和湖泊效应形态之间的关系已被证明具有挑战性，以前的工作者特别确定需要更好地了解地形在改变结构过渡区中的作用。更广泛的影响：该项目解决了改善湖泊影响地区天气和气候预测的社会需求。其他更广泛的影响包括：（1）将研究成果注入到本科生和研究生课程、培训课程和基于网络的教育模块中，（2）指导两名研究生并扩大妇女对NSF赞助项目的参与，以及（3）通过与NSF GK-12研究生奖学金计划合作，提高公众对科学的理解，该计划涉及研究生研究人员在K-12教室教授湖城学区的基于发现的环境科学。