Collaborative Research: Cloud Macrophysical Parameterization and Its Application to Aerosol Indirect Effects

这笔拨款将支持三所大学和三个政府实验室的合作研究工作，以开发一种方法来表示大气边界层（即距离地表约2公里内的水平）的液态水云。这种方法的首字母缩写为CLUBB（由双法线统一的云），它将解决气候模型网格框的大小（通常为100公里）与边界层云（可能为100米）中出现的小得多的上升和下降气流之间的差异。该研究将使用各种观测数据，并结合更详细的模型（包括大涡模拟模型）的模拟，构建垂直速度、温度、湿度和水流星种类的联合概率密度函数（pdf）。pdf格式将用于模拟云的形成（特别是边界层积云和层积云），以及云的反射率和其他特性在多大程度上由气溶胶决定。CLUBB将在两个气候模型中实施，一个在国家大气研究中心，另一个在NOAA地球物理流体动力学实验室。这项研究是响应气候过程和建模小组（CPTs）的征求而提出的，该小组的目的是在三年的时间内对气候模型进行改进。由于气候模型是气候相关研究的基础研究工具，预计该CPT项目的成果将具有广泛的科学和实际效益。此外，决策者在考虑应对气候变率和气候变化的战略时，越来越需要气候模型作为决策支持工具。因此，气候模式的改进为政策决策提供了更好的指导。此外，这笔资金将用于支持三名研究生的教育，以及三名博士后研究人员的就业和指导。

This grant will support a collaborative research effort at three universities and three government laboratories to develop a method to represent liquid water clouds in the atmospheric boundary layer (i.e. at levels within about 2km of the surface). The method, which has the acronym CLUBB (clouds unified by binormals), will address the disparity between the size of a climate model grid box (typically 100km) and the much smaller sizes of the updrafts and downdrafts which occur in boundary layer clouds (perhaps 100m). The research will use a variety of observations in concert with simulations from more detailed models (including large-eddy simulation models) to construct joint probability density functions (PDFs) for vertical velocity, temperature, moisture, and hydrometeor species. The PDFs will then be used to simulate the formation of clouds (particularly boundary layer cumulus and stratocumulus clouds) and the extent to which cloud reflectivity and other properties are determined by aerosols. CLUBB will be implemented in two climate models, one at the National Center for Atmospheric Research and one at the NOAA Geophysical Fluid Dynamics Laboratory. The research was proposed in responsee to a solicitation for Climate Process and Modeling Teams (CPTs), which are intended to perform work yielding improvements to climate models over a three-year time period.The results of this CPT project are expected to have broad scientific and practical benefits, since climate models are a basic research tool in climate-related research. Furthermore, climate models are increasingly in demand as tools for decision support by policy makers considering strategies to address climate variability and climate change. Thus, improvements in climate models offer the prospect of better guidance for policy decisions. In addition, the grant will support the education of three graduate students, and for the employment and mentoring of three postdoctoral researchers.