VOCALS: Comprehensive Studies of Marine Stratocumulus during VOCALS-REx Using Airborne Radar, Lidar, and In Situ Measurements

VOCALS：VOCALS-REx 期间使用机载雷达、激光雷达和原位测量对海洋层积云进行综合研究

• 批准号: 0745986
• 负责人: David Leon
• 金额: $ 57.66万
• 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: 2008
• 资助国家: 美国
• 起止时间: 2008-04-01 至 2012-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0745986&HistoricalAwards=false
• 关键词: VOCALS; Comprehensive; Studies; Marine; Stratocumulus

It is now recognized that drizzle is a common feature of marine stratocumulus clouds and that it has an important impact on the heat, water, and aerosol budgets of cloud decks. Additionally, analyses of mesoscale organization in marine stratocumulus clouds (typically on a scale of 5 - 100 km) show that drizzle is the key process linking mesoscale organization and cloud microphysical processes. The formation of pockets of open cells (POCs), which is believed to result from drizzle-aerosol-cloud interactions, results in large changes in cloud-fraction and albedo - properties of cloud decks that are significant for the climate. While the formation of POCs is the most dramatic example of these linkages, it is only one of many manifestations of drizzle-aerosol-cloud interactions that determine the characteristics of the stratocumulus layer. As such, there is a pressing need for observational studies that provide quantitative estimates of drizzle rates and of processes directly linked to drizzle (such as the removal of aerosol particles) and for a comprehensive depiction of the kinematic, thermodynamic, and cloud-microphysical structure within different types of mesoscale organization; these can be used to investigate drizzle-cloud structure linkages and for comparison with structures obtained from numerical simulations.This project will contribute to the quantitative and qualitative needs by deploying a suite of instruments on the NSF C-130 aircraft during VOCALS-REx (VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment). Measurements that will include: vertical cross-sections of radar reflectivity and Doppler velocity, measurements of cloud-base height, cloud condensation nuclei (CCN), aerosol, and hydrometeor size spectra. Reflectivity cross-sections and vertical-plane velocity fields from the radar will be used to identify and characterize mesoscale structures within the stratocumulus-topped boundary layer and, through the use of a conditional sampling approach, to develop a composite depiction of mesoscale structures. Radar cross-sections will also provide a context for other measurements made onboard the NSF C-130.Expected outcomes include: quantitative estimates, which will be incorporated into integrated VOCLALS-REx datasets, of: precipitation rate (cloud-base and sea surface), cloud-base and cloud-top heights, sub-cloud aerosol and CCN spectra, and the rate of CCN removal due to drizzle; an assessment of probable mechanisms underlying the transition from unbroken to broken marine stratocumulus will be made using the composite depictions of the mesoscale structures.Two broader impacts are expected: First, in collaboration with other VOCALS investigators, integrated datasets from VOCALS-REx will be compiled and made available to the atmospheric science community. In conjunction with other VOCALS-REx investigators, parameterizations of cloud microphysical processes in terms of cloud macrophysical characteristics will be developed. Second, expertise in the synergistic use of radar, lidar and in situ observations will be developed through graduate student training.

现在认识到毛毛雨是海洋层积云的一个共同特征，它对云面的热量、水和气溶胶收支有重要影响。此外，对海洋层积云（典型尺度为5 - 100 km）中尺度组织的分析表明，毛毛雨是连接中尺度组织和云微物理过程的关键过程。被认为是由毛毛雨-气溶胶-云相互作用导致的开胞囊（POC）的形成，导致对气候具有重要意义的云层的云分数和云层特性的巨大变化。虽然POC的形成是这些联系中最引人注目的例子，但它只是决定层积云特征的毛毛雨-气溶胶-云相互作用的许多表现之一。因此，迫切需要对毛毛雨率和与毛毛雨直接相关的过程进行定量估计的观测研究（如气溶胶粒子的去除）和全面描述不同类型中尺度组织内的运动学、热力学和云微物理结构;这些可以用来研究毛毛雨，云结构联系，并与数值模拟获得的结构进行比较。该项目将通过部署一套在VOCALS-REx（VAMOS海洋-云-大气-陆地研究区域实验）期间，NSF C-130飞机上的仪器。测量将包括：雷达反射率和多普勒速度的垂直截面，云底高度的测量，云凝结核（CCN），气溶胶和水凝物尺寸谱。将利用雷达的反射率截面和垂直面速度场来确定和描述层积云顶边界层内的中尺度结构，并通过使用条件取样方法来综合描述中尺度结构。雷达截面还将为NSF C-130上进行的其他测量提供背景。预期结果包括：定量估计，将纳入综合VOCLALS-REx数据集：降水率（云底和海面）、云底和云顶高度、云下气溶胶和云凝结核谱，以及由于毛毛雨造成的云凝结核的去除率;将利用中尺度结构的合成图来评估海洋层积云从完整到破碎转变的可能机制。预计会有两个更广泛的影响：首先，将与其他VOCALS研究人员合作，汇编VOCALS-REx的综合数据集，并提供给大气科学界。将与其他VOCALS-REx研究人员一起，根据云的宏观物理特征，制定云微物理过程的参数。第二，将通过研究生培训发展协同使用雷达、激光雷达和现场观测的专门知识。

项目成果

Droplet Concentration and Spectral Broadening in Southeast Pacific Stratocumulus Clouds

东南太平洋层积云中的液滴浓度和光谱展宽

• DOI: 10.1175/jas-d-16-0043.1
• 发表时间: 2017
• 期刊: Journal of the Atmospheric Sciences
• 影响因子: 3.1
• 作者: Snider, Jefferson R.;Leon, David;Wang, Zhien
• 通讯作者: Wang, Zhien

Modeling chemical and aerosol processes in the transition from closed to open cells during VOCALS-REx

• DOI: 10.5194/acp-11-7491-2011
• 发表时间: 2011-08
• 期刊: Atmospheric Chemistry and Physics
• 影响因子: 6.3
• 作者: J. Kazil;J. Kazil;Hailong Wang;G. Feingold;G. Feingold;A. Clarke;J. Snider;A. Bandy

Calibration of the passive cavity aerosol spectrometer probe for airborne determination of the size distribution

• DOI: 10.5194/amt-6-2349-2013
• 发表时间: 2013-01-01
• 期刊: ATMOSPHERIC MEASUREMENT TECHNIQUES
• 影响因子: 3.8
• 作者: Cai, Y.;Snider, J. R.;Wechsler, P.
• 通讯作者: Wechsler, P.