Atmospheric Lakes of Vapor Drifting Over the East Coast of Africa

非洲东海岸漂流的大气湖

• 批准号: 2141492
• 负责人: Brian Mapes
• 金额: $ 39.08万
• 依托单位: University of Miami
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2141492&HistoricalAwards=false
• 关键词: Atmospheric; Lakes; Vapor; Drifting; Over

As long-lived and isolated moist air masses, “atmospheric lakes” are observed to drift slowly across the western equatorial Indian Ocean after pinching off from the vast area of moist air over the broad Indo-Pacific warm pool. These lakes nurture clusters of precipitating deep convection, and their landfalls produce much-needed rain over the generally dry eastern African coast. To date, very little is known about these lakes, and new knowledge about them may help manage local water resource and improve weather forecasting over a region where synoptic meteorology is little studied. By using global reanalysis data, observations, and outputs from operational forecast and climate models, the work aims to understand these lakes by examining their governing processes that involve the intimately coupling of convection, dynamics, turbulence, and radiation. The work will train a graduate student.As natural laboratories of moist tropical atmosphere, atmospheric lakes may be Earth’s closest analogues to convective self-aggregation, a much-studied contemporary paradigm of tropical climate in need of observational touchstones. Guided by hypotheses, the investigators will compile lake-following budgets of water vapor and of the closely related (but more richly interpretable) moist static energy. The MERRA-2 reanalysis offers all terms for closed budgets, including analysis tendencies indicative of model process shortcomings. Independently measured satellite imagery will be used to characterize the cloud field, including the potential aggregation of convective systems. The resulting quantitative depiction of the lakes’ maintenance and propagation processes will serve as a target and challenge to the project’s comparative studies of weather-forecast and climate-simulation model data. New processes which come in at landfall will also be examined carefully, as they impact eastern Africa and its people through rainfall.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.

作为长寿且孤立的湿气团，“大气湖”在从广阔的印度太平洋暖池上空的大片湿空气中消失后，缓慢地漂过赤道西印度洋。这些湖泊孕育了集群。迄今为止，人们对这些湖泊知之甚少，而有关它们的新知识可能有助于管理当地水资源并改善整个地区的天气预报。这项工作旨在通过使用全球再分析数据、观测结果以及业务预测和气候模型的输出，通过检查涉及对流、动力学、湍流和大气的密切耦合的控制过程来了解这些湖泊。这项工作将培训一名研究生。作为潮湿热带大气的天然实验室，大气湖可能是地球上最接近对流自聚集的类似物，对流自聚集是需要大量研究的当代热带气候范例。在假设的指导下，研究人员将编制水蒸气和密切相关（但更容易解释）的湿静态能量的湖泊跟踪预算，MERRA-2 再分析提供了封闭预算的所有术语，包括指示性分析趋势。独立测量的卫星图像将用于描述云场的特征，包括对流系统的潜在聚集，从而对湖泊的维持和传播过程进行定量表示。该项目对天气预报和气候模拟模型数据进行比较研究的目标和挑战还将仔细审查登陆时出现的新过程，因为它们通过降雨影响东非及其人民。该奖项反映了美国国家科学基金会的法定使命和使命。通过使用基金会的智力优点和更广泛的影响审查标准进行评估，该项目被认为值得支持。