Entrainment and Microphysics of Stratocumulus Clouds

这个项目的目的是研究混合过程和云滴的生长，作为DYCOMS-II（海洋层积云动力学和化学）的一部分，这是2001年7月在加利福尼亚海岸进行的一个野外合作项目。该实验项目以美国国家科学基金会的C-130研究飞机为基础，将提供前所未有的高分辨率空气运动、温度和湿度数据。Gerber博士的粒子体积监测器（PVM）也将被部署，以提供有关云水含量精细变化的信息。将进行与云顶夹带和混合有关的四项研究：利用高分辨率测量液态水含量、湿度和垂直空气速度来估计夹带速率。2 .对液态水含量波动谱在几米尺度上出现明显“尺度断裂”的原因进行调查。3 .制定云顶层结构的概念模型。探讨不同温度的空气团混合引起云顶附近凝结增强的可能性。研究的最终目标是提高模拟海洋层积云发展的能力，同时考虑云顶的混合过程。这将有助于在气候模式中更好地参数化云过程。

The objective of this project is to study mixing processes and cloud droplet growth as part of DYCOMS-II (Dynamics and Chemistry of Marine Stratocumulus), a collaborative field program conducted off the coast of California in July 2001. The experimental program, based on the NSF C-130 research aircraft, will provide data of unprecedented high resolution on air motions, temperature, and humidity. The Particle Volume Monitor (PVM) of Dr. Gerber will also be deployed, to give information on the fine-scale variability of cloud water content. Four studies related to entrainment and mixing at cloud top will be undertaken:1. Estimation of entrainment rate using high-resolution measurements of liquid water content, humidity, and vertical air velocity.2. Investigation of the cause of an apparent "scale break" at a scale of several meters in the spectrum of liquid water content fluctuations.3. Formulation of a conceptual model of the structure of the cloud-top layer.4. Exploring the possibility of enhanced condensation near cloud top caused by the mixing of air parcels with different temperatures.The ultimate goal of the research is to improve the ability to model the development of marine stratocumulus clouds, taking into account mixing processes at cloud top. This will lead to better parameterization of cloud processes in climate models.