Exploiting Synergies between Remote Sensing and in Situ Measurements during ICE-T to Better Understand Ice Generation in Tropical Clouds

尽管长期以来人们认识到云中冰的成核和增殖过程对于降水过程以及云对全球气候的辐射影响的重要性，但我们对非均质冰成核机制和冰增殖过程的相关性的了解仍然有限。我们对冰形成过程的认识上的差距阻碍了云的数值模拟中冰形成过程的参数化，从而导致了在数值模式中模拟的云的辐射特性和降水的不确定性。云中冰实验(ICE)是利用改进的观测能力(包括改进的现场探测器和机载多普勒雷达和激光雷达)来研究不同条件下云中的冰成核的一系列现场活动。冰热带(ICE-T)，将研究东加勒比海上空浅层对流云中的冰形成。怀俄明州云雷达(WCR)和上下视版本的怀俄明州云激光雷达(WCL)将在ICE-T期间搭载在NSF(国家科学基金会)/NCAR(国家大气研究中心)C-130飞机上飞行，并将用于观测云中的冰发生。这项研究将有助于理解云动力学和微物理过程之间的关系。激光雷达后向散射和去偏振测量将与PCASP(被动腔气溶胶光谱探头)和FSSP-300(前向散射光谱探头)测量结合使用，以识别气溶胶分布和尘埃层。通过对比沙尘和非沙尘条件下云中冰的形成和发展，研究沙尘对云中冰形成的影响。WCR的双多普勒能力将被用来研究冰在云中的传输，并探索云动力学和冰形成/增殖之间的联系。WCR和WCL的结合将允许雷达观测到的反射率和速度场与混合相区的边界明确地联系在一起。在本次调查期间收集的雷达、激光雷达和现场气溶胶数据将有助于ICE-T其他调查人员进行分析。一名毕业生将参加ICE-T实地活动和数据分析阶段。还将通过该项目的各个阶段开展数据传播和其他更广泛的外联工作。最后，对大气中冰的成核和增殖机制的更好的理解将导致在数值模式中改进冰过程的参数化，进而在全球气候模式中产生更好的云模拟。

Despite longstanding recognition of the importance of ice nucleation and multiplication processes in clouds, both for precipitation processes as well as for the radiative impact of clouds on global climate, our understanding of heterogeneous ice nucleation mechanisms and the relevance of ice multiplication processes remains limited. The gaps in our understanding of ice formation processes hinder parameterization of ice initiation processes in numerical simulations of clouds, thus leading to uncertainties in cloud radiative properties and precipitation simulated in numerical models.The Ice in Clouds Experiments (ICE) are a series of field campaigns investigating ice nucleation in clouds in a range of different conditions, taking advantage of improvements in observational capabilities including improved in situ probes and airborne Doppler radar and lidar. ICE-Tropical (ICE-T), will investigate ice formation in shallow, convective clouds over the eastern Caribbean.Intellectual merits. The Wyoming Cloud Radar (WCR), together with upward- anddownward-looking versions of the Wyoming Cloud Lidar (WCL) will be flown on the NSF (National Science Foundation)/NCAR (National Center for Atmospheric Research)C-130 aircraft during ICE-T and will be used to observe ice occurrence within cloud.This research will help understanding the relationship between cloud-dynamics andmicrophysical processes. Lidar backscatter and depolarization measurements will be used in conjunction with the PCASP (Passive Cavity Aerosol Spectrometer Probe) and FSSP-300 (Forward Scattering Spectrometer Probe) measurements to identify aerosol distributions and dust layers. The effect of dust on ice formation in clouds will be examined by contrasting ice formation and development in clouds under dusty vs. non-dusty conditions.The dual-Doppler capability of the WCR will be used to investigate how ice is transported inside cloud, and explore the link between cloud dynamics and iceinitiation/multiplication. The combination of WCR and WCL will allow the reflectivity and velocity fields observed by the radar to be unambiguously linked to the boundaries ofthe mixed-phase region.Broader impacts. Radar, lidar, and in situ aerosol data collected during thisinvestigation will facilitate analyses conducted by other ICE-T investigators. A graduatestudent will participate in the ICE-T field campaign and data analysis phase. Data dissemination and other broader outreach efforts will also be carried out through various phases of this project. Finally, an improved understanding of ice nucleation andmultiplication mechanisms in the atmosphere will lead to improved parameterizations ofice processes in numerical models, in turn lead to a better cloud simulations in globalclimate models.