Precipitation Studies in Trade Wind Clouds - The Rain In Cumulus over the Ocean (RICO) Experiment

这是“海洋积云中的雨”(RICO)实验的中心项目，该实验是一个多机构合作项目，涉及15个以上的机构，计划在2004年11月至2005年1月研究信风积云。研究将涵盖四个主要范畴：*导致热带积云迅速开始降水的过程；*热带积云中由初始降水系统向成熟降水系统的过渡；*信风积云对信风层性质的影响；以及*降水在信风机制中能量平衡中的作用。研究的重点是调查暖云中降雨的形成速度，这似乎比模型或计算所预测的要快。研究人员将调查几个已经提出的解释降水快速开始的假说，包括巨型粒子、湍流和夹带的作用。在这项研究中，他们将使用最近开发的观测能力，包括探测降水形成性质的新雷达能力，以及测量云滴和气溶胶粒子尺寸分布的新仪器。研究人员还试图研究信风积云的更大范围的特征和影响，最终有助于更好地理解这些地区和降水在气候系统中的作用。该项目的广泛影响包括强烈的教育因素。该项目和更广泛的RICO实验将通过研究生和新的研究人员参与实验，并通过与实地实验有关的特别研究生研讨会，来推动这一研究领域的研究生和新研究者的培训。这也是更广泛的RICO实验围绕其组织的核心努力，因此为涉及许多其他研究人员和机构的协调互动努力提供了核心。预计的长期影响将是，信风积云和暖云降雨的影响可以在天气和气候模式中更好地反映出来，因此可以改进对降水的预测。

This is a central project for the "Rain in Cumulus over the Ocean" (RICO) experiment, a multi-institutional collaborative project involving more than 15 institutions that plans to study trade-wind Cumulus clouds in Nov 2004 - Jan 2005. The studies will cover four key areas: * the processes that lead to rapid onset of precipitation in tropical cumulus clouds; * the transition from initiation to mature precipitating system in such clouds; * the effect of tradewind Cumuli on the properties of the tradewind layer; and * the role of precipitation in the energy balance in the tradewind regime.A focus of the study is an investigation of the rate at which rain forms in warm clouds, which appears to be faster than predicted by models or calculations. The investigators will investigate several hypotheses that have been advanced to explain this rapid onset of precipitation, including the roles of giant particles, turbulence, and entrainment. In the study, they will use recently developed observational capabilities, including new radar capabilities for detecting the nature of precipitation formation and new instruments for measuring the size distributions of cloud droplets and aerosol particles. The investigators also seek to study larger-scale characteristics and effects of tradewind Cumuli, eventually leading to improved understanding of the roles of these regions and of precipitation in the climate system.Broader impacts of this project include a strong educational component. This project and the broader RICO experiment will advance the training of graduate students and new investigators in this line of research through their involvement in the experiment and also through a special graduate-student seminar to be conducted in connection with the field experiment. This has also been the core effort around which the broader RICO experiment organized, and so has provided the nucleus for a concerted interactive effort involving many other investigators and institutions. The expected long-range impact will be that the effects of trade-wind Cumulus and of rain from warm clouds can be better represented in weather and climate models and so can lead to improved predictions of precipitation.