Unraveling the Impacts of Ocean Surface Current Gradients and Ocean Surface Waves on Atmospheric Boundary Layer Physical Processes over the Gulf Stream Using COAWST Model

使用 COAWST 模型揭示海面洋流梯度和海面波浪对湾流上空大气边界层物理过程的影响

• 批准号: 2307335
• 负责人: Mark Bourassa
• 金额: $ 57.52万
• 依托单位: Florida State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-01 至 2026-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2307335&HistoricalAwards=false
• 关键词: Unraveling; Impacts; Ocean; Surface; Current; Unraveling; Impacts; Ocean; Surface; Current

This research focuses on how ocean surface currents and waves work with the atmosphere to cause winds that move heat and moisture in a manner that influences weather related to the Gulf Stream. Location-to-location differences in currents and waves cause differences in the surface friction felt by the atmosphere, which results in areas of increased vertical motion over these locations. That motion helps transport heat and moisture to heights that influence weather. This study investigates if these processes are important before storms and during storms. If these processes are found to be important, the knowledge obtained will improve weather forecasts. A significant amount of this research will be carried out by a graduate student; thus, contributing to the training of the next generation of modelers with expertise in interaction between the ocean and atmosphere. Modeling tools developed will also help future science investigations of these processes.This research will improve understanding of the atmospheric responses to momentum-related air-sea coupling processes on fine spatial scales (10 to 40 km) and at shorter timescales (from hours to several days). This project will focus on the Gulf Stream region where horizontal gradient of ocean surface current is large and where impacts on weather are more likely to be large. The Coupled Ocean-Atmosphere-Wave-Sediment Transport (COAWST) modeling system will be modified to more different types of models of surface drag because prior work has shown surprisingly strong sensitivity to the surface stress parameterization in high-resolution (2-6 km) two-way coupled ocean/wave/atmosphere models. Four twin experiments will determine the atmospheric sensitivity to winds and waves after accounting for how two-way coupling modifies the waves and currents. In each twin experiment, the two-way coupled model is run to obtain the ocean and atmosphere states. Then the ocean state obtained from the coupled run is prescribed to force the atmosphere without the dependency on currents or waves. Differences between couple runs and between members of each pair are diagnosed. Validation of surface characteristics sensitive to stress parameterization will provide insights about the strengths and weakness of each surface stress parameterization. This project is anticipated to (1) determine how coupling of winds, currents, and waves modifies budgets of heat, moisture, and horizontal momentum; (2) determine the extent to which vertical transport within the atmospheric boundary-layer (ABL) and between the ABL and free atmosphere is enhanced by wave and current influences on stress; (3) determine how much the enhanced vertical motion and transport in the coupled model contributes to increased convection and storm intensity; and (4) determine how the answers to the above three questions change depending on weather regimes (e.g., boundary layer stability, wind speed, and interaction with atmospheric fronts).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

这项研究着重于海洋表面电流和波浪如何与大气一起起作用，以引起风和水分的风，以影响与海湾流有关的天气的方式。电流和波浪的位置对位置差异会导致大气感觉到表面摩擦的差异，从而导致这些位置上垂直运动的区域增加。这种运动有助于将热量和水分运输到影响天气的高度。这项研究调查了这些过程在暴风雨前和暴风雨中是否很重要。如果发现这些过程很重要，则获得的知识将改善天气预报。这项研究将由研究生进行。因此，有助于对海洋与大气之间相互作用的专业知识的下一代建模者进行培训。开发的建模工具还将有助于对这些过程的未来科学研究。这项研究将提高人们对精细空间尺度（10至40 km）和较短的时间表（从小时到几天到几天）上对与动量相关的空中耦合过程的大气反应的理解。该项目将重点放在墨西哥湾流动区域，在海洋表面电流的水平梯度很大，并且对天气的影响更大。耦合的海洋 - 大气 - 波波 - 辅助运输（COAWST）建模系统将被修改为更多不同类型的表面阻力模型，因为先前的工作表现出了令人惊讶的对高分辨率（2-6 km）双向耦合耦合海洋/波/波/大气模型的表面应力参数化的敏感性。四个双胞胎实验将确定对双向耦合如何修饰波和电流的大气敏感性。在每个双胞胎实验中，运行双向耦合模型以获得海洋和大气状态。然后，规定了从耦合奔跑中获得的海洋状态，以强迫大气，而无需依赖电流或波浪。夫妇运行之间的差异以及每对成员之间的差异。对应力参数化敏感的表面特征的验证将提供有关每个表面应力参数化的优势和劣势的见解。预计该项目将（1）确定风，电流和波的耦合如何改变热，水分和水平动量的预算； （2）确定大气边界层（ABL）内的垂直传输以及ABL和自由大气之间的垂直传输的程度，并通过波和电流对压力的影响增强； （3）确定耦合模型中增强的垂直运动和运输的多少有助于对流和风暴强度的增加； （4）确定上述三个问题的答案如何根据天气制度（例如边界层稳定性，风速和与大气方面的互动）的变化。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛的审查标准通过评估来通过评估来支持的。