Understanding clouds and precipitation at the sub kilometer scale using HAMP – The edge of shallow precipitation (UCP-HAMP-Edge)

在信风区，降水的形成是通过限制边界层和对流云的增长来维持分散的浅积云制度的关键过程。这种效应部分决定了浅云对全球变暖的反应，以及这些云是否加速和减缓气候变化。控制浅云是否开始沉淀的影响因素尚未完全解开，特别是由于缺乏全面的观测。使用研究飞机HALO进行的EUREC 4A测量活动（阐明云-环流耦合在气候中的作用）将克服这一限制，同时提供云的宏观和微观物理特性的观测结果以及亚千米尺度的凝结物负荷，以及大尺度动力学和基本能量和水分通量的估计。EUREC 4A将于2020年1月和2月举行，探索巴巴多斯的云层。提议者是发起这一运动的国际小组的一部分，并将操作由微波辐射计和HALO机载云雷达组成的“HALO微波包”。作为解决科学问题的基础，我们将开发协同云和雨检索和扩展分段云数据库，包括以前的NARVAL活动。该数据集既用于卫星评估，也用于评估网格间距在100米到几公里之间的下一代大气模型。

The formation of precipitation is a key process in the trade wind region to maintain a scattered shallow cumulus regime by limiting the growth of the boundary layer and of convective clouds. This effect partly determines how shallow clouds will respond to global warming and whether these clouds accelerate und reduce the climate change. The influencing factors controlling whether a shallow cloud starts to precipitate are yet not fully unraveled, in particular due to a lack of comprehensive observations. The measurement campaign EUREC4A (Elucidating the Role of Cloud-Circulation Coupling in Climate) using the research aircraft HALO will overcome this limitation and provide simultaneously observations of cloud macro- and microphysical properties and the condensate load at the sub kilometer scale as well as estimates of the large scale dynamics and underlying energy and moisture fluxes. EUREC4A will take place at January and February 2020 and explore clouds eats of Barbados. The proposers are part of the international team, which initiated this campaign, and will operate the "HALO microwave package" (HAMP) consisting of microwave radiometers and a cloud radar onboard of HALO. As basis to address the science question we will develop of synergistic cloud and rain retrievals and the extension of a segmented cloud database including also the preceding NARVAL campaigns. This data set is used both for satellite evaluation and to evaluate the next generation of atmospheric models with grid spacing between 100m and a few kilometers.