Aerosol/Boundary Layer Cloud Interactions--Simulations and Parameterization Testing

智力上的功绩。这项研究的重点是加强对降水边界层云的理解，并开发这些云的参数化，以用于更大尺度的模式，如大气环流气候模式(GCM)和业务预报模式。首席调查员(PI)将对最近在海洋积云(RICO)试验现场活动中观测到的部分案例进行降水信风积云的大涡模拟。特别是，PI将研究云凝结核(CCN)和巨云凝结核(GCCN)浓度的变化如何改变云的集合平均特性，如云量、平均液态水含量、云寿命、垂直速度谱、云辐射特性和降雨量。由于RICO是少数几个提供热力学、风、CCN和GCCN浓度测量以及云特性的现场机载和雷达测量的现场活动之一，它提供了一个独特的机会来测试降水LES模式、参数化微物理和云降水边界层的单柱模式的性能。预计这些模拟还将有助于进一步加深对信风情况下气溶胶云相互作用的基本了解。此外，RICO提供了一个独特的机会来校准和测试正在开发中的参数化区域云成核气溶胶源-汇/输送模式。此外，PI将使用在其他实地活动中收集的数据来校准和测试这个形成云核的气溶胶模型，这些活动已经获得了对这些重要气溶胶的至少一些成分的测量。气溶胶源模式与云分辨率模式和中尺度模式相结合，然后将用来检查世界各地云属性和降水量的潜在变异性。更广泛的影响。研究表明，云核气溶胶浓度的可变性可以对气候模拟和预报以及定量降水预报产生显著影响。模拟研究的目的是进一步量化这些气溶胶对云特性和降水的作用。此外，正在开发和试验的参数化云模式和云成核气溶胶源模式被设计为可以移植到业务中长期预报模式中，从而改善天气和气候预报。

Intellectual Merit. This research focuses on improving understanding of precipitating boundary layer clouds and developing parameterizations of those clouds for use in larger scale models such as general circulation climate models (GCM) and operational forecast models. The Principal Investigator (PI) will perform large-eddy simulations (LES) of precipitating trade wind cumuli for selected cases observed during the recent Rain in Cumulus over the Ocean (RICO) Experiment field campaign. In particular, the PI will examine how variations in the concentrations of cloud condensation nuclei (CCN) and giant cloud condensation nuclei (GCCN) alter the ensemble-averaged properties of clouds such as cloud cover, average liquid water contents, cloud lifetimes, vertical velocity spectra, cloud radiative properties, and rainfall. Because RICO is one of the few field campaigns that provides measurements of thermodynamics, winds, and CCN and GCCN concentrations, as well as in situ airborne and radar measurements of cloud properties, it provides a unique opportunity to test the performance of precipitating LES models, parameterized microphysics, and single-column models of the cloudy precipitating boundary layer. It is anticipated that these simulations will also contribute to furthering fundamental understanding of aerosol cloud interactions in the trade wind regime. Moreover, RICO provides a unique opportunity to calibrate and test a parameterized regional cloud nucleating aerosol source-sink/transport model under development. In addition, the PI will calibrate and test this cloud-nucleating aerosol model using data collected in other field campaigns that have obtained measurements of at least some components of these important aerosols. The aerosol source model coupled to cloud-resolving and mesoscale models will then be used to examine the potential variability of cloud properties and precipitation at various locations around the world. Broader Impacts. Research is suggesting that variability of cloud nucleating aerosol concentrations can have appreciable impacts on climate simulations and forecasts, and on quantitative precipitation forecasts. The modeling studies are designed to further quantify the role of those aerosols on cloud properties and precipitation. In addition, the parameterized cloud models and cloud-nucleating aerosol source model being developed and tested are designed such that they could be migrated into operational medium range and long range forecast models which could lead to improved forecasts of weather and climate.