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.

作为长期存在和孤立的潮湿气团，人们观察到，从广阔的印度-太平洋暖水池上方的大片潮湿空气中剥离出来的“大气湖泊”，慢慢地漂移到赤道西印度洋。这些湖泊孕育了大量降水的深对流，它们的登陆在通常干燥的东非海岸产生了急需的降雨。到目前为止，人们对这些湖泊知之甚少，关于它们的新知识可能有助于管理当地水资源，并改善一个天气气象学研究较少的地区的天气预报。通过使用全球再分析数据、观测数据以及业务预报和气候模式的输出，这项工作旨在通过检查这些湖泊的控制过程来了解它们，这些过程涉及对流、动力学、湍流和辐射的密切耦合。这项工作将培养一名研究生。作为潮湿热带大气的自然实验室，大气湖泊可能是地球上最接近对流自聚集的类似物，对流自聚集是一种需要观测试金石的当代热带气候的广泛研究范例。在假设的指导下，研究人员将编制水蒸气和与之密切相关(但更容易解释)的湿静态能量随湖泊变化的预算。MERRA-2再分析提供了关闭预算的所有条件，包括表明模型流程缺陷的分析趋势。将使用独立测量的卫星图像来描述云场的特征，包括对流系统的潜在聚集。由此产生的湖泊维护和繁殖过程的定量描述将成为该项目对天气预报和气候模拟模型数据的比较研究的目标和挑战。在登陆时进入的新过程也将被仔细检查，因为它们通过降雨影响东非及其人民。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。