Mesoscale Boundary Layer Structures Observed During the Lake-Induced Convection Experiment (Lake-ICE)

湖诱发对流实验（Lake-ICE）中观察到的中尺度边界层结构

• 批准号: 9816203
• 负责人: Mark Hjelmfelt
• 金额: --
• 依托单位: South Dakota School of Mines and Technology
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-04-15 至 2002-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9816203&HistoricalAwards=false
• 关键词: Mesoscale; Boundary; Layer; Structures; Observed

The state of knowledge of air-sea interactions indicate that current scientific problems (such as weather forecasting and global change) require increased understanding of marine boundary layers in complex surface and synoptic conditions. Lake-effect snow storms, which develop over the Great Lakes during fall and winter cold air outbreaks, are useful "laboratories" for the study of complex boundary layer growth and mesoscale circulation patterns. Data collected during the recent Lake-Induced Convection Experiment (Lake-ICE) offer a unique opportunity to gain insight into the development of convective boundary layers, mesoscale circulations in complex conditions, and interrelationships between growing boundary layers and the ambient synoptic conditions.Past research efforts of the principal investigators have provided considerable insight into the development of lake-effect boundary roll convection and mesoscale snowbands in conditions of intense surface heating and strongly stable upwind conditions. However, these efforts revealed the importance of atmospheric and surface conditions close to the upwind shore of Lake Michigan, where no observational data were available. Data from Lake-ICE allow for direct testing of these hypotheses and an expansion of knowledge of the effects of non-classic, complex surface and atmospheric conditions on boundary layer growth and mesoscale circulation patterns. Specifically, the principal investigators propose to (1) understand the evolution of roll/cellular convection and boundary layer growth across Lake Michigan, (2) determine the influences of synoptic conditions, lake-surface temperature variations, and air-mass modification by Lake Superior, on boundary layer growth and mesoscale circulations over Lake Michigan, and (3) determine the respective mechanisms controlling the evolution of lake-effect vortices of different scales over the Great Lakes.The proposed research will utilize the unique dataset available from the 1997/1998 field operations of the Lake-ICE, supplemented with data taken during two past field experiments conducted over the Great Lakes. Of particular importance to the proposed research efforts will be the use of the NCAR Electra Doppler Radar (ELDORA), WSR-88D, and satellite observations to quantify spatial and temporal variations in mesoscale boundary layer circulation patterns in lake-effect events. Numerical modeling efforts will use the Advanced Regional Prediction System (ARPS) to develop a better understanding of the physical processes responsible for variations in mesoscale circulation patterns and boundary layer growth in complex convective boundary layers and to determine the sensitivity of their characteristics over a wider range of atmospheric conditions than can be obtained by observations alone. 2

海气相互作用的知识状况表明，当前的科学问题（例如天气预报和全球变化）需要加强对复杂地表和天气条件下海洋边界层的了解。 秋季和冬季冷空气爆发期间五大湖上空形成的湖泊效应暴风雪是研究复杂边界层增长和中尺度环流模式的有用“实验室”。 最近的湖泊诱发对流实验 (Lake-ICE) 期间收集的数据提供了一个独特的机会，可以深入了解对流边界层的发展、复杂条件下的中尺度环流，以及不断增长的边界层与周围天气条件之间的相互关系。 过去的研究主要研究人员的努力为在强烈的表面加热和高度稳定的逆风条件下湖效应边界滚流对流和中尺度雪带的发展提供了相当多的见解。 然而，这些努力揭示了密歇根湖逆风岸附近大气和地表条件的重要性，那里没有观测数据。 Lake-ICE 的数据可以直接测试这些假设，并扩展非经典、复杂的表面和大气条件对边界层生长和中尺度环流模式影响的知识。具体来说，主要研究人员建议（1）了解密歇根湖的滚转/细胞对流和边界层生长的演变，（2）确定天气状况、湖面温度变化和苏必利尔湖的气团改变的影响，关于密歇根湖上空的边界层增长和中尺度环流，以及（3）确定控制五大湖上不同尺度的湖泊效应涡旋演化的各自机制。拟议的研究将利用来自密歇根湖的独特数据集1997/1998 年 Lake-ICE 实地作业，并补充了过去两次在五大湖进行的实地实验所获取的数据。 对于拟议的研究工作特别重要的是使用 NCAR Electra 多普勒雷达 (ELDORA)、WSR-88D 和卫星观测来量化湖泊效应事件中中尺度边界层环流模式的空间和时间变化。 数值模拟工作将使用高级区域预测系统（ARPS）更好地了解导致中尺度环流模式变化和复杂对流边界层边界层增长的物理过程，并确定其特征在更广泛范围内的敏感性比仅通过观测可以获得的大气条件。 2