Cumulus Ensemble Sensitivities

对流云场在时间和空间尺度上表现出连贯的天气和气候变化，相对于单个积云和云系而言，这种变化非常大。在缺乏足够观测的情况下，这项研究将使用云分辨模式来探索大气对流对其大尺度环境的敏感性。将检验三个假设：1.)在自由对流层中，深对流的发生对湿度有很大的敏感性。2.)深对流的发生对对流层下部的温度异常比对流层上部的温度异常更为敏感。3.)对流的大尺度变化主要取决于小尺度波动统计量的大尺度变化，而不仅仅是平均条件的大尺度变化。预计这项研究的结果将有助于大气模式中的积云参数化工作。该项目涉及一名博士后助理的参与。

Fields of convective clouds exhibit coherent weather and climate variability on time and space scales that are very large with respect to individual cumulus clouds and cloud systems. In the absence of adequate observations, this study will employ cloud resolving models to explore the sensitivity of atmospheric convection to its large-scale setting. Three hypotheses will be tested: 1.) The occurrence of deep convection has a large sensitivity to humidity in the free troposphere. 2.) The occurrence of deep convection is more sensitive to temperature anomalies in the lower than the upper troposphere. 3.) Large-scale variations of convection depend importantly on large-scale variations of the statistics of small-scale fluctuations, and not just on large-scale variations of mean conditions.It is expected that the results from this study will usefully inform cumulus parameterization efforts in atmospheric models. The project involves the participation of a post-doctoral associate.