Development of Parameterizations of Aerosol/Cloud Interactions and Assessment of Their Potential Climatic Impacts

气溶胶/云相互作用参数化的发展及其潜在气候影响的评估

• 批准号: 0215367
• 负责人: William Cotton
• 金额: $ 47.78万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-01 至 2005-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0215367&HistoricalAwards=false
• 关键词: Development; Parameterizations; Aerosol; Cloud; Interactions

This is a modeling-based investigation of the interactions of clouds and aerosols and the effects of these interactions on cloud dynamics, precipitation, and radiative transfer. It is an extension of a recent study of the cloudy boundary layer, based on what is called the assumed probability density function (PDF) method. Within every computational grid box of the cloud model, it is assumed that the joint probability of vertical velocity, potential temperature, and liquid water content satisfies a parametric form such as the multivariate Gaussian. Large-eddy simulation (LES) provides information on the small-scale variability of these quantities, enabling the estimation of the parameters of the distribution. The cloud model predicts the development in time of the mean values of the quantities in the grid boxes and the PDF model characterizes the subgrid-scale variability. In this project, the previous work will be extended to include precipitation processes and the estimation of the effects of variable concentrations of cloud condensation nuclei and ice forming nuclei on the microphysical, dynamic, and radiative properties of clouds. The feasibility of applying the technique to large cumulonimbus clouds (deep convection) will be investigated. Sensitivity studies will determine the extent to which changes in aerosol characteristics can affect the clouds and influence regional climate.

这是一个基于模拟的云和气溶胶的相互作用的调查，这些相互作用对云动力学，降水和辐射传输的影响。 它是最近对多云边界层研究的一个扩展，基于所谓的假定概率密度函数（PDF）方法。 在云模型的每个计算网格框内，假设垂直速度、位温和液态水含量的联合概率满足参数形式，例如多元高斯。 大涡模拟（LES）提供了这些量的小尺度变化的信息，使分布参数的估计。 云模型预测网格框中数量的平均值的时间发展，PDF模型表征亚网格尺度的变化。 在这个项目中，以前的工作将扩展到包括降水过程和云凝结核和冰形成核的浓度变化对云的微物理，动力学和辐射特性的影响的估计。 将研究将该技术应用于大型积雨云（深对流）的可行性。 敏感性研究将确定气溶胶特性的变化对云层和区域气候的影响程度。