Diagnoses of Ice Initiation in Clouds from Airborne In Situ, Radar and Lidar Observations

通过机载原位、雷达和激光雷达观测诊断云中结冰过程

• 批准号: 0650609
• 负责人: Gabor Vali
• 金额: $ 46.43万
• 依托单位: University of Wyoming
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-05-01 至 2011-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0650609&HistoricalAwards=false
• 关键词: Diagnoses; Ice; Initiation; Clouds; Airborne

The importance of the ice phase in the atmosphere - for the global water cycle, for chemical processes, for energy exchanges - has been well recognized for many decades. Research to understand the processes involved in how ice forms has been intense, yet the complexity of the problem makes progress slow. Difficulties arise from the many pathways that exist for the nucleation of ice particles, and from the complicated dynamic situations in which those processes are embedded. There are important shortcomings in observations, and also in the theoretical underpinnings of the relevant components of numerical models. The great variety of conditions in which ice particles are formed in tropospheric clouds dictates that observations be collected in a wide range of conditions and that those observations be analyzed to isolate the most likely mechanisms for ice particle formation in the different situations.The goal of this project is to apply an observational approach to delineating and quantifying ice initiation processes in clouds, and to support analysis of observation with model calculations. Use will be made of observations made with in situ instrumentation, and the Wyoming Cloud Radar, which were mounted on the Wyoming King Air and the NSF/NCAR C-130 research aircraft for a series of field projects over the past decade that, among other activities, included observations in ice-phase and mixed-phase clouds. New observations also will be obtained in the ICE-L field campaign of 2007. Included in these observations will be data from the newly-developed Wyoming Cloud Lidar. This new analysis of past aircraft observations, along with analysis of new observations from ICE-L, will provide much new information on ice initiation. The remote sensing instruments (radar and lidar) on board the aircraft complement the data from the in situ sensors in a very effective way, both with respect to defining the spatial distribution of the concentrations and sizes of hydrometeors, but also for the definition of the dynamic context of the in situ measurements. The cloud types included in the study are wave clouds, mountain cap clouds, and stratiform clouds. Features relevant to the question of ice initiation have been already identified in each of these cloud types and provide the starting points for the work. In addition, there will be a focus on the presence, in the stratiform cloud types, of highly localized sources of ice which exhibit spatial intermittency but temporal continuity.The research will have the broader impacts of enhancing the involvement in research of participating young scientists and students in work related to ice initiation, under the guidance of a veteran researcher. There will be significant impacts in the continued development of the Wyoming King Air and the Wyoming Cloud Radar, both of which are available to the wider NSF research community via the NSF Atmospheric Sciences Lower Atmospheric Observing Facility.

几十年来，大气中冰相对于全球水循环、化学过程和能量交换的重要性已得到充分认识。 了解冰形成过程的研究一直很紧张，但问题的复杂性使得进展缓慢。困难来自于冰粒子成核存在的许多途径，以及这些过程所嵌入的复杂的动态情况。 观测以及数值模型相关组成部分的理论基础都存在重要缺陷。 对流层云中冰粒形成的条件多种多样，这要求在各种条件下收集观测结果，并分析这些观测结果，以找出不同情况下冰粒形成最可能的机制。该项目的目标是应用观测方法来描绘和量化云中的冰起始过程，并通过模型计算支持观测分析。 将利用现场仪器和怀俄明云雷达进行的观测，怀俄明云雷达安装在怀俄明国王航空和 NSF/NCAR C-130 研究飞机上，用于过去十年中的一系列现场项目，其中包括冰相和混合相云的观测。 新的观测数据也将在 2007 年的 ICE-L 实地活动中获得。这些观测数据中将包括来自新开发的怀俄明州云激光雷达的数据。 对过去飞机观测的新分析，以及对 ICE-L 新观测的分析，将提供许多关于结冰的新信息。 飞机上的遥感仪器（雷达和激光雷达）以非常有效的方式补充来自现场传感器的数据，既可以定义水汽凝结物浓度和大小的空间分布，也可以定义现场测量的动态背景。 研究中包括的云类型有波浪云、山帽云和层状云。 与冰引发问题相关的特征已经在每种云类型中被识别出来，并为这项工作提供了起点。 此外，还将重点关注层状云类型中高度局部化的冰源的存在，这些冰源表现出空间间歇性但时间连续性。该研究将产生更广泛的影响，在资深研究人员的指导下，加强年轻科学家和学生参与冰引发相关工作的研究。 怀俄明国王航空和怀俄明云雷达的持续发展将产生重大影响，这两个雷达都可以通过 NSF 大气科学低层大气观测设施向更广泛的 NSF 研究界提供。