Collaborative Research: Characterizing interactions between tropical deep convection and the environment using a buoyancy framework

热带对流风暴在全球天气和气候中发挥着重要作用。在目前的计算技术下，不可能直接对对流的所有方面进行建模，因此科学家依赖于参数化，即编码到模型中的近似值。对地球气候的模拟对热带对流的参数化特别敏感，因此科学界有责任提高对热带对流的理解，以改进进入天气和气候模拟的参数化。在这个项目中，研究小组计划使用一个新的框架来研究热带对流如何与其周围环境相互作用，该框架专注于将地球表面附近的空气卷进风暴中。除了改进数值模拟的潜力外，研究小组还将组织一次讲习班，让热带对流研究界聚集在一起，其中包括一批初出茅庐的科学家和学生。这一项目的首要目标是继续努力确定一个可用于解释各尺度降水变异性的热带深对流概念模式。研究小组将建立在“降水-浮力(P-B)框架”的基础上，该框架将降水与估计携带的羽流浮力联系在一起。研究小组将围绕两个主要研究问题开展工作：(1)对流不稳定的“网格尺度”O(100公里)综合测量在多大程度上准确地评估大气支持深对流的能力，以及(2)我们如何改进网格尺度的平均不稳定测量，以说明不同尺度上的可变性和动力学？研究人员将使用新的中尺度对流跟踪数据库、冷池梯度特征探测算法、长期雷达数据、现场战役数据和卫星观测，并结合新的合成技术来处理以下目标：1.描述降水-浮力(“P-B”)关系如何随空间尺度上的对流变化而变化。2.研究P-B阈值随中尺度对流系统演化的变化，估计不同生命周期阶段深对流对其热力环境的敏感性。3.描述动力相互作用--质量通量/卷吸、风切变、涡度、冷池--如何改变对深对流演变的热力学控制。4.应用改进的P-B框架研究热带地区的昼夜、区域和季节内降水变化。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。

Tropical convective storms play a significant role in global weather and climate. With current computing technology, it is impossible to directly model all aspects of convection, so scientists rely on parameterizations, which are approximations that are coded into the models. Simulations of Earth’s climate are particularly sensitive to the parameterizations of tropical convection, so it is incumbent on the scientific community to improve understanding of tropical convection to improve the parameterizations that go into weather and climate modeling. In this project, the research team plans to study how tropical convection interacts with its surrounding environment using a new framework that focuses on the entrainment of air near the Earth's surface into the storm. In addition to the potential to improve numerical modeling, the research team will organize a workshop to bring together the tropical convection research community, including a diverse set of early-career scientists and students.The overarching goal of this project is to continue work towards identifying a conceptual model for tropical deep convection that can be used to explain precipitation variability across scales. The research team will build upon the “precipitation-buoyancy (P-B) framework” which relates precipitation and estimates of entraining plume buoyancy. The research team will center their work around two main research questions: (1) to what extent do “grid-scale” O(100 km) integrated measures of convective instability accurately assess the capacity of the atmosphere to support deep convection, and (2) how can we refine grid-scale average instability measures to account for variability and dynamics across scales? The investigators will use new mesoscale convective tracking databases, cold pool gradient feature detection algorithms, long-standing radar data, field campaign data, and satellite observations, combined with novel compositing techniques to address the following objectives:1. Characterize how the precipitation-buoyancy (“P-B”) relationship varies as a function of convective variability across spatial scales. 2. Examine how P-B thresholds change as a function of mesoscale convective system evolution, estimating the sensitivity of deep convection to its thermodynamic environment throughout different lifecycle stages. 3. Characterize how dynamical interactions - mass flux/entrainment, wind shear, vorticity, cold pools - modify thermodynamic controls on deep convective evolution. 4. Apply the refined P-B framework to study diurnal, regional, and intraseasonal precipitation variability across the tropics.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.