DCMEX: The Deep Convective Microphysics EXperiment

DCMEX：深对流微物理实验

• 批准号: NE/T006439/1
• 负责人: Martin Gallagher
• 金额: $ 138.43万
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FT006439%2F1
• 关键词: DCMEX; Deep; Convective; Microphysics; EXperiment

The goal of the DCMEX project is to ultimately reduce the uncertainty in equilibrium climate sensitivity by improving the representation of microphysical processes in global models. It is the anvils produced by tropical systems in particular that contribute significantly to cloud feedbacks. The anvil radiative properties, lifetimes and areal extent are the key parameters. DCMEX will determine the extent to which these are influenced, or even controlled by the cloud microphysics including the habits, concentrations and sizes of the ice particles that make up the anvils, which in turn depend on the microphysical processes in the mixed-phase region of the cloud as well as those occurring in the anvil itself.There has been a rapid advancement in the sophistication of global climate models in recent years. Yet some of the equations used to represent microphysics processes are based on a poorer physical understanding than desired. Gettelman and Sherwood (2016), for example pointed out that there is significant spread in determining cloud feedbacks across different global models due to uncertainties in microphysical processes, such as the treatment of ice processes. Ceppi et al. (2017) also concluded that accurately representing clouds and their radiative effects in global models remains challenging partly due to the difficulty in representing the cloud microphysics, as well as the interactions between microphysics and dynamics. The microphysical and radiative processes and dynamics that control the opacity and areal coverage of tropical anvil clouds are not well represented in global climate models.DCMEX will make novel measurements of cloud microphysics in a real-world laboratory convective cloud system - both the mixed-phase region and anvil - as well as improve and test models and then apply them globally to tropical deep convective systems. We propose to deploy the FAAM aircraft along with two dual-polarisation, Doppler radars and airborne and ground-based aerosol measurements to study the deep convective clouds that form over an isolated mountain range in New Mexico. The focus will be on the formation of ice from ice nucleating particles (INPs) (primary ice production) and by processes involving existing ice particles (secondary ice particle production), such as collisions. These observations will be used to test and further refine the representation of ice processes in climate models. Our approach recognises that in order to represent cloud feedbacks accurately a model needs to represent the individual processes within the system accurately. Demonstrating that the model is able reproduce the observed evolution of these clouds is therefore a necessary condition for the accurate prediction of cloud feedbacks.The research in DCMEX will have a robust pathway from a novel field campaign to more accurate estimates of climate sensitivity. This pathway is built with four integrated parts: new observations; the use of these observations and process modelling to derive new parametrisations; the use of existing in-situ data and satellite observations of anvils in tropical deep convection to validate the model; and use of the knowledge gained to improve and test the representation of microphysics in climate models. In particular, DCMEX will build on the experience of our groups in improving microphysical representation. A seamless suite of Met Office models will be used for convection- resolving simulations and global simulations with parametrised convection. Finally, simplified climate change (imposed warmer environment) experiments will be carried out to understand the role of the different microphysical processes on cloud feedbacks.

DCMEX项目的目标是最终通过改善全球模型中微物理过程的表示，最终降低气候灵敏度的不确定性。尤其是热带系统产生的砧座对云反馈产生了显着贡献。砧辐射特性，寿命和面积范围是关键参数。 DCMEX将确定这些受影响的程度，甚至受云微物理学的影响，包括构成砧座的冰颗粒的习惯，浓度和尺寸，这又取决于云本身的混合阶段区域中的微物理过程以及在烟灰本身中发生的那些杂种量很快。然而，用于表示微物理过程的一些方程是基于比所需的差的身体理解。例如，Gettelman和Sherwood（2016）指出，由于微物理过程中的不确定性，例如对冰过程的处理，确定不同全球模型的云反馈存在显着差异。 Ceppi等。 （2017年）还得出结论，准确地代表云及其在全球模型中的辐射效应仍然具有挑战性，部分原因是代表云微物理学的困难以及微物理学与动力学之间的相互作用。控制热带砧云的不透明度和面部覆盖的微观物理和辐射过程和动力学在全球气候模型中没有很好地表示。DCMEX将在现实世界实验室的对流云系统中对云微物理学进行新颖的测量，并在混合模型和Anvil -exterction and Inter Inter Inter Intermand Inders Intermants Insperction中，并在全球范围内进行了深入的指标。我们建议部署FAAM飞机以及两个双极化，多普勒雷达和空气寄生和地面气溶胶测量值，以研究在新墨西哥州孤立山脉上形成的深对流云。重点将放在冰核颗粒（INP）（初级冰）以及涉及现有冰颗粒（二次冰颗粒产生）的过程中，例如碰撞。这些观察结果将用于测试和进一步完善气候模型中冰过程的表示。我们的方法认识到，要准确地表示云反馈，模型需要准确地表示系统内的各个过程。因此，证明该模型能够重现这些云的观察到的演变是准确预测云反馈的必要条件。DCMEX的研究将具有从新颖的现场活动到更准确的气候灵敏度估计的强大途径。该途径是由四个集成部分建造的：新的观测；使用这些观察和过程建模来得出新的参数；在热带深度对流中使用现有的原位数据和卫星观察以验证模型；并使用获得的知识来改善和测试气候模型中微物理学的表示。特别是，DCMEX将基于我们小组在改善微物理表示形式方面的经验。 MET Office模型的无缝套件将用于对流 - 解决对流的模拟和全球模拟。最后，将进行简化的气候变化（施加温暖的环境）实验，以了解不同的微物理过程在云反馈中的作用。

项目成果

DCMEX coordinated aircraft and ground observations: Microphysics, aerosol and dynamics during cumulonimbus development

DCMEX 协调飞机和地面观测：积雨云发展过程中的微物理、气溶胶和动力学

• DOI: 10.5194/essd-2023-303
• 发表时间: 2023
• 作者: Finney D