Collaborative Research: Multi-Scale Study of Lake Breezes and the Impact of Marine Boundary Layers on Convection in the Great Lakes Region

合作研究：湖风的多尺度研究以及海洋边界层对五大湖区对流的影响

• 批准号: 0709526
• 负责人: Neil Laird
• 金额: $ 28.87万
• 依托单位: Hobart and William Smith Colleges
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0709526&HistoricalAwards=false
• 关键词: Collaborative; Research; Multi; Scale; Study

Coastal zones of the United States are crucially important to many aspects of society. More than half of the United States population lives within 80 km of a coastline and greater than 40 million people reside in the Great Lakes region. Great Lakes lake breezes, which occur most often during the spring and summer months, can have large economic, societal, and climatic impacts on coastal regions. Lake-breeze circulations can significantly modify the near coastal environments by providing cooler temperatures, affecting the development of severe thunderstorms, influencing precipitation amounts and locations, and altering air pollution concentrations and transport. Despite considerable research on lake breezes, and to a lesser amount on lake-cooled, stable marine boundary layers, limited fundamental scientific understanding of several important areas remain. A number of numerical modeling and laboratory studies suggest that urban areas have large impacts on lake-breeze (or similar sea-breeze) circulations, generally resulting in a decrease in inland movement after the lake-breeze front has reached the urban center. At present, there exists very limited observational information on how sea- and lake-breezes typically move in the vicinity of near-shore urban areas as compared to non-urban areas. A preliminary investigation of lake-breeze frontal movement through two urban areas in the Great Lakes suggests that the expected decrease in inland movement occurs infrequently. This research seeks to determine the variability of lake-breeze movement in these areas and examine the environmental conditions that contribute to the spatial and temporal variations. There has been recent interest within the meteorological community in examining and understanding the connections between mesoscale systems and climate variability. Great Lakes lake breezes provide an exceptional opportunity to examine this issue. Past investigations of lake-breeze occurrence have examined a limited number of locations in the Great Lakes region over varying timescales. These studies have provided important, but incomplete, information about the spatial and temporal variability of lake breezes. This research seeks to quantify the inter-annual, intra-seasonal, and spatial variations in Great Lakes lake-breeze occurrence and determine their impact on near-shore climate conditions. Few studies have examined the influence of the warm-season marine boundary layers on convective systems and the precipitation distribution in the Great Lakes region. In fact, the forecasting community continues to assert that one of the most significant summer forecast challenges in the Great Lakes region is the impact, if any, that the marine layer will have on an existing convective system as it crosses a lake. This research seeks to address the gap of knowledge on this issue by understanding the relationship between the evolution of convective systems and marine layer stability and environmental conditions.Intellectual Merit: Results of the studies will provide new insight into several areas of limited and often conflicting scientific understanding: (a) the influence of urban areas on lake-breeze fronts and the impact of environmental conditions on the lake breeze response to urban areas, (b) the inter-annual, intra-seasonal, and spatial variability of lake breezes and their influence on coastal climate conditions, and (c) the interaction of convective systems with lake-cooled marine boundary layers. These studies will address several fundamental aspects of lake breezes and significantly contribute to the understanding of the impact the Great Lakes have on coastal urban areas, severe weather and precipitation systems, and regional climate conditions. Broader Impacts: Results of the studies will provide an enhanced understanding of coastal meteorology which affects a host of activities related to commerce, industry, transportation, health, safety, recreation, and national defense. As recently recommended to the larger atmospheric science community, the research will examine air-land interactions, the effects of land-sea breezes, and the climatology of mesoscale systems through the use of observational data subsequently allowing for improved evaluation of regional climate simulations. In addition, the research will notably contribute to benefiting the next generation of scientists. Undergraduate students will be involved through participation in the established summer research program at Hobart and William Smith Colleges. Graduate students will benefit by active participation in a successful research program at the University of Illinois and Illinois State Water Survey. Results will be widely communicated to the scientific community through journal articles and conference presentations and to the operational forecast and air quality communities through regional workshops and presentations.

美国沿海地区对社会的许多方面都至关重要。 超过一半的美国人口居住在距海岸线 80 公里范围内，超过 4000 万人居住在五大湖地区。 五大湖的湖风最常发生在春季和夏季，会对沿海地区产生巨大的经济、社会和气候影响。 湖风环流可以通过提供较低的温度、影响严重雷暴的发展、影响降水量和地点以及改变空气污染浓度和运输来显着改变附近沿海的环境。 尽管对湖风进行了大量研究，对湖泊冷却、稳定的海洋边界层进行了大量研究，但对几个重要领域的基础科学认识仍然有限。许多数值模型和实验室研究表明，城市地区对湖风（或类似的海风）环流有很大影响，通常会导致湖风锋到达城市中心后内陆运动减少。 目前，与非城市地区相比，关于海风和湖风通常如何在近岸城市地区附近移动的观测信息非常有限。 对穿过五大湖两个城市地区的湖风锋面运动的初步调查表明，预期的内陆运动减少很少发生。 这项研究旨在确定这些地区湖风运动的变化性，并检查导致空间和时间变化的环境条件。最近，气象界对检查和理解中尺度系统与气候变化之间的联系产生了兴趣。 五大湖的湖风为研究这个问题提供了绝佳的机会。 过去对湖风发生的调查在不同的时间尺度上检查了五大湖地区有限的几个地点。 这些研究提供了有关湖风时空变化的重要但不完整的信息。 本研究旨在量化五大湖湖风发生的年际、季节内和空间变化，并确定其对近岸气候条件的影响。很少有研究探讨暖季海洋边界层对五大湖地区对流系统和降水分布的影响。 事实上，预报界继续声称，五大湖地区夏季预报面临的最重大挑战之一是海洋层穿过湖泊时对现有对流系统的影响（如果有的话）。 本研究旨在通过了解对流系统的演化与海洋层稳定性和环境条件之间的关系来解决这一问题上的知识空白。 学术价值：研究结果将为几个有限且经常相互冲突的科学认识领域提供新的见解：（a）城市地区对湖风锋面的影响以及环境条件对城市地区湖风响应的影响，（b）年际、季节内和 湖风的空间变化及其对沿海气候条件的影响，以及（c）对流系统与湖泊冷却的海洋边界层的相互作用。 这些研究将解决湖风的几个基本方面，并极大地有助于了解五大湖对沿海城市地区、恶劣天气和降水系统以及区域气候条件的影响。更广泛的影响：研究结果将加深人们对沿海气象学的了解，沿海气象学影响着商业、工业、交通、健康、安全、娱乐和国防等一系列活动。 正如最近向更大的大气科学界建议的那样，该研究将通过使用观测数据来研究气地相互作用、陆海风的影响以及中尺度系统的气候学，随后改进对区域气候模拟的评估。 此外，这项研究将显着有助于造福下一代科学家。本科生将通过参加霍巴特学院和威廉史密斯学院既定的夏季研究项目来参与。 研究生将受益于积极参与伊利诺伊大学和伊利诺伊州水调查的成功研究项目。 结果将通过期刊文章和会议演讲广泛传播给科学界，并通过区域研讨会和演讲广泛传播给业务预报和空气质量界。