Collaborative Research: Cloud System Evolution in the Trades

合作研究：行业云系统演进

• 批准号: 1445813
• 负责人: Robert Wood
• 金额: $ 48.22万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1445813&HistoricalAwards=false
• 关键词: Collaborative; Research; Cloud; System; Evolution

This study aims to understand the evolution of the boundary layer cloud, aerosol and thermodynamic structures along trajectories within the north-Pacific trade-winds using observations from the NSF/NCAR Gulfstream V (HIAPER). This effort includes characterization of the cloud, precipitation and aerosol fields in the stratocumulus (Sc) and the fair-weather cumulus (Cu) regimes within the subtropical easterlies over the northern Pacific and the use of Large Eddy Simulation (LES) models to simulate the cloud evolution along the trajectories sampled. Intellectual merit: These characterizations along trajectories will be designed to aid in our understanding and simulation of the transition between the two convective regimes - a critical factor in the climate system. LES models have become a robust tool for Lagrangian simulations of subtropical cloudiness transitions, but there are few good datasets for comprehensively testing these simulations. In particular, adequate observations of the coupled evolution of aerosol, cloud droplet number concentration and precipitation during such transitions are lacked. Thus, the observing strategy will be to sample aerosol, cloud, precipitation, and boundary layer properties upwind from the transition zone over the North Pacific and to resample these areas two and four days later. This Lagrangian approach is designed to minimize uncertainties in the large-scale forcing due to horizontal advection in the lower troposphere as air masses move from colder to warmer sea surface temperatures and thus facilitate model simulations and isolate critical physical processes. Two key elements of the observing system will be a newly developed HIAPER Cloud Radar (HCR) and the HIAPER High Spectral Resolution Lidar (HSRL). The HCR will be used to provide cloud and precipitation characteristics. The HSRL will provide cloud boundaries and aerosol characteristics when viewing non-cloudy volumes. A full suite of probes on the aircraft will be used for in situ measurements of aerosol, cloud, precipitation, and turbulence properties. Two modes of operations will be made on flights between the west coast of California and Hawaii. One will include remote sensing (mapping) of the clouds and boundary layer from flight levels above the boundary layer made upstream and downstream from the Sc to Cu transition zone. The other will involve detailed profiling in the subcloud and cloud layer in two or three selected areas upstream and downstream from the transition zone to make detailed in situ measurements of aerosols, clouds, precipitation, and turbulence. On the surveying legs dropsondes will be used to obtain the thermodynamic and wind structure in and above the boundary layer. Several flight sequences are planned for the June-July 2015 timeframe. The observations made on these flights will be used to evaluate the moisture, dry static energy and mass budgets by estimating the changes in these parameters between the upstream Sc region sampled on one flight and the downstream Cu region sampled on the subsequent flights. The synthesis of the observations will provide an observational framework for LES studies that will provide a better understating of cloud system evolution in the trades. Broader impacts: The project will develop observing and analysis techniques and strategies that will facilitate the development of future missions aimed at studying boundary layer clouds in remote areas that are not easily reached by other observing platforms. The data sets developed will be useful for evaluating satellite retrieval techniques and for evaluating models and model parameterizations applied to a wide range of scales--microphysical, mesoscale, regional, and global. The educational components of this project will include the training of graduate and undergraduate students on the technical aspects of the data collection processes, flight operations, and the subsequent analysis of data to address key science questions. Further, integration of observations from the project into teaching and learning modules that can be used at both the undergraduate and the graduate level will be developed.

这项研究旨在使用NSF/NCAR Gulfstream V（Hiaper）的观测值来了解北太平洋贸易风中边界层云，气溶胶和热力学结构的演变。这项工作包括在北太平洋地区亚热带伊斯特利体内的云层（SC）（SC）（SC）（SC）中的云，降水和气溶胶场的表征以及使用大型涡模拟（LES）模型的使用，以模拟沿轨迹采样的云演化。知识分子的优点：沿轨迹的这些特征将旨在帮助我们理解和模拟两个对流制度之间的过渡 - 气候系统的关键因素。 LES模型已成为Lagrangian对亚热带多云转变模拟的强大工具，但是很少有良好的数据集可以全面测试这些模拟。特别是，缺乏对气溶胶的耦合演化的足够观察，在此类过渡过程中缺乏云液滴浓度和降水。因此，观察策略将是采样气溶胶，云，降水和边界层的特性，从北太平洋上过渡区向上风格，并在两天后两天和四天在这些区域进行重新采样。这种Lagrangian方法旨在最大程度地减少由于空气质量从较冷到更温暖的海面温度转移到较高的对流层的水平对流，因此在大规模强迫中的不确定性最小化，从而促进模型模拟并隔离关键的物理过程。观测系统的两个关键要素将是新开发的Hiaper Cloud Radar（HCR）和Hiaper高光谱分辨率激光雷（HSRL）。 HCR将用于提供云和降水特征。观看非云量时，HSRL将提供云边界和气溶胶特性。飞机上的一套探针将用于气溶胶，云，降水和湍流特性的原位测量。在加利福尼亚和夏威夷西海岸之间的航班上将进行两种操作模式。一个将包括云的遥感（映射）和边界层的遥控器，从SC到Cu过渡区的上游和下游的边界层上方的飞行级别。另一个将涉及在过渡区和下游的两个或三个选定区域的子云和云层中的详细分析，以对气溶胶，云，降水和湍流进行详细的现场测量。在测量腿上，滴滴将用于获得边界层和上方的热力学和风结构。计划在2015年6月至7月的时间范围内进行几个飞行序列。这些航班上的观察结果将用于评估水分，干燥的静态能量和质量预算，通过估计在一次飞行中采样的上游SC区域之间的这些参数的变化以及随后航班采样的下游CU区域。观察结果的综合将为LES研究提供一个观察框架，该框架将更好地低估交易中云系统的演变。更广泛的影响：该项目将开发观察和分析技术和策略，这些技术和策略将有助于开发未来的任务，旨在研究偏远地区的边界层云，而其他观察平台不容易达到。开发的数据集将有助于评估卫星检索技术以及评估应用于多种尺度的模型和模型参数化 - 微物理，中尺度，区域和全球。该项目的教育组成部分将包括对数据收集过程，飞行操作的技术方面的研究生和本科生的培训，以及随后的数据分析以解决关键科学问题。此外，将开发在本科和研究生级别可以使用的教学和学习模块中的观察结果。