Interactions between trade wind shallow cumuli and their environment

浅积云是地球上最常见的云类型;在热带信风中无处不在，它们的行为对我们理解大气至关重要，但仍然知之甚少。这些在大气层低的小而浅的对流云在调节其环境的热力学和动力学方面发挥着重要作用;通过凝结使云层变暖，将水分输送到上面的逆温层，并通过云滴的蒸发和降水使逆温层和云下层冷却（Zhu和Bretherton 2004，Neggers等人2007）。此外，这些云产生冷却辐射效应，反射短波辐射。浅积云行为的一个特别不确定的方面是它们与气候变化和气溶胶扰动的关系和反应。浅层对流与对流层的相互作用对气候敏感性有很大的影响，它们的反馈是模型之间气候敏感性扩散的主要原因（舍伍德等人，2014）。先前的研究表明，云丰度和降水量等数量对气溶胶增加的响应存在争议（Xue等人，2008年; Lonitz等人，2015年）。这些云的另一个有趣的特征是，尽管它们的个体尺寸很小，但根据当地的条件，它们能够产生中尺度环流，从而产生大的有组织的云模式和云簇。该组织的变化可能对云量产生很大影响（Vogel等人，2016年），鉴于这些云的无处不在的性质及其对环境的影响，这是非常重要的。

The shallow cumulus cloud is the most prevalent cloud type on Earth; ubiquitous in the trade winds of the Tropics, their behaviour is critical to our understanding of the atmosphere, and yet is still poorly understood. These small, shallow convective clouds low in the atmosphere play an important role in regulating the thermodynamics and dynamics of their environment; warming the cloud layer through condensation, transporting moisture to the inversion layer above, and cooling of both the inversion, and the sub-cloud layer, through the evaporation of cloud droplets and precipitation (Zhu and Bretherton 2004, Neggers et al. 2007). Additionally, these clouds exert a cooling radiative effect, reflecting shortwave radiation. One particularly uncertain aspect of the behaviour of shallow cumuli is their relationship and response to a changing climate, and aerosol perturbations. The interactions of shallow convection with the troposphere have large implications for climate sensitivity, and their feedbacks are responsible for much of the spread in climate sensitivity between models (Sherwood et al. 2014). Previous works have shown contesting responses of quantities such as cloud abundance and precipitation to increases in aerosol (Xue et al. 2008, Lonitz et al. 2015). Another interesting feature of these clouds is that, despite their small individual size, and depending on local conditions, they are capable of producing mesoscale circulations which result in large organised patterns and clusters of clouds. Changes in this organisation can have large impacts on cloud amount (Vogel et al., 2016), which, given the ubiquitous nature of these clouds and their effects on their environment, is highly significant.