Microphysics and Optics in Trade Wind Cumulus Clouds

信风积云中的微观物理和光学

• 批准号: 0345695
• 负责人: Hermann Gerber
• 金额: $ 15.6万
• 依托单位: Gerber Scientific Inc.
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-10-01 至 2006-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0345695&HistoricalAwards=false
• 关键词: Microphysics; Optics; Trade; Wind; Cumulus

This study will be part of the Rain in Cumulus over the Ocean (RICO) experiment, a collaborative study of trade-wind Cumuli and of rain formation in warm clouds that will be conducted in the winter of 2004-2005. This investigator will have primary responsibility for two airborne instruments, a Particle Volume Monitor (PVM) to measure the liquid water content of clouds and a new integrating nephelometer that measures the surface area of the cloud droplet population. The RICO studies of precipitation formation and of mechanisms that broaden the cloud droplet size distribution will benefit from accurate measurement of the liquid water content, and the integrating nephelometer will provide a benchmark for other instruments that measure the cloud droplet size distribution. Because the PVM can measure the liquid water content at very high rate (up to 1000 Hz), its measurements will provide an important opportunity to identify the degree to which cloud parcels are diluted by entrainment of environmental air, a process that has an important effect on rain formation. This and other studies in RICO are expected to lead to a better understanding of how rain forms in clouds that do not reach the freezing level and a better characterization of precipitation and other processes that occur in shallow trade-wind clouds. Because such clouds cover large areas of the Earth and are now poorly understood, this study in association with others in RICO has the potential to lead to better representations of precipitation and radiative transfer in climate models.

这项研究将是海洋上空积云降雨实验的一部分，该实验将于2004-2005年冬季对信风积云和暖云中降雨的形成进行合作研究。该研究员将主要负责两个机载仪器，一个是测量云的液态水含量的粒子体积监测器，另一个是测量云滴总数表面积的新的积分浊度计。RICO对降水形成和扩大云滴大小分布的机制的研究将受益于对液态水含量的准确测量，积分浊度计将为测量云滴大小分布的其他仪器提供基准。由于PVM可以以非常高的速率（高达1000 Hz）测量液态水含量，其测量将提供一个重要的机会来确定云团被环境空气夹带稀释的程度，这是一个对降雨形成有重要影响的过程。RICO的这一研究和其他研究预计将导致更好地了解雨如何在没有达到冻结水平的云中形成，并更好地描述降水和发生在浅信风云中的其他过程。由于这种云覆盖了地球的大部分地区，现在还知之甚少，这项研究与RICO中的其他研究相结合，有可能在气候模型中更好地表示降水和辐射传输。