Ice Nucleating Particle Influence on Southern Ocean Clouds: Measurements and Analyses for Southern Ocean Clouds, Radiation, Aerosol, Transport Experimental Study (SOCRATES)

冰成核粒子对南大洋云的影响：南大洋云、辐射、气溶胶、传输实验研究的测量和分析（苏格拉底）

• 批准号: 1660486
• 负责人: Paul DeMott
• 金额: $ 72.63万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-03-01 至 2022-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1660486&HistoricalAwards=false
• 关键词: Ice; Nucleating; Particle; Influence; Southern

The Southern Ocean (SO), meaning the global ocean of the high latitude Southern Hemisphere, has a well-deserved reputation as the stormiest place on earth. The remoteness of the SO and its unforgiving conditions have severely limited observations of atmospheric processes occurring above it, including cloud processes in the cyclones traveling along the South Polar front. Yet these processes are of interest for a variety of reasons, including the fact that SO clouds are relatively free from the effects of continental and anthropogenic aerosols, and the region is thus a natural laboratory for the study of cloud behavior under pristine conditions. SO clouds also play a significant cooling role in the energy balance of the planet by reflecting incoming sunlight back to space. There is evidence to suggest that this cooling has a long-range effect on the distribution of the low-latitude rainfall associated with the intertropical convergence zone, and that changes in SO cloudiness due to global climate change will affect the location and strength of the Southern Hemisphere jet stream. One indicator of our lack of understanding of SO cloud processes is the inadequate SO cloud cover found in climate model simulations, which is accompanied by excessive absorption of sunlight by the ocean surface which may in turn cause errors in estimates of climate sensitivity. The deficiency in simulated cloud cover is most pronounced in boundary layer and lower-tropospheric clouds (tops below 3km) in the cold, dry sectors of frontal weather systems traveling along the SO storm track.The work funded under this award is part of a larger field campaign titled Southern Ocean Clouds, Radiation, Aerosol, Transport Experimental Study (SOCRATES). The primary activity of the campaign is the deployment of a Gulfstream V (GV) research aircraft maintained by the Earth Observing Laboratory of the National Center for Atmospheric Research. The GV will be based in Hobart, Australia and make multiple flights across the South Polar front collecting data on SO clouds and the meteorological conditions in which they occur. The GV is equipped with dropsondes to record ambient meteorological conditions, radar and lidar to observe the clouds, and instruments mounted on the wings or positioned behind inlets to to sample, collect and analyze aerosols and cloud particles (liquid droplets and ice crystals). The SOCRATES campaign is complementary to SO activities planned internationally and by other US agencies, including surface observations taken on ships and on MacQuarie Island, a small uninhabited island at 54 degrees South.A key issue to be addressed in the campaign is the relative abundance of supercooled liquid water (SLW) droplets and ice particles in SO clouds, as SLW is more prevalent in SO clouds than their Northern Hemisphere counterparts. The PIs hypothesize that the extent to which SLW cloud droplets freeze into ice particles is more strongly modulated in SO clouds by the vigor of cloud updrafts than by the availability of Ice nucleating particles (INPs, particles within liquid droplets which trigger freezing). The PIs also seek to determine the relative influence of overlying free tropospheric aerosol concentrations versus local surface and boundary layer controls, including precipitation and wind speed, in determining the concentration of liquid droplets in boundary layer clouds.Work in this project is specifically focused on understanding the formation of ice crystals in SO clouds, a necessary step in determining whether the relatively low abundance of ice particles compared to SLW droplets is due to a dearth of INPs. A specialized wing-mounted inlet called a counterflow virtual impactor (CVI) is used to collect cloud liquid droplets and ice crystals and separate them from ambient aerosols and other non-cloud material. Further processing using a device known as a continuous flow diffusion chamber (CFDC) separates INPs from cloud condensation nuclei (CCN, the particles on which water vapor condenses to form liquid droplets) which are not conducive to ice formation. INPs are collected and later analyzed using laboratory techniques including electron and X-ray microscopy to determine their composition and other properties. Similar data is collected on an Australian research vessel operating in the same region. These data are combined with additional campaign data to address questions including:* Are INP concentrations predictive of the extent of cloud glaciation?* What are the relative roles of sea spray from the underlying ocean and long-range transport in the free troposphere as sources for INPs in SO clouds?* Can INP characteristics and abundances be related to surface seawater composition (measured on the research vessel), including organic matter and biological activity?* What evidence do SOCRATES observations provide for the occurrence or absence of secondary ice formation processes (i.e. ice particles formed from other ice particles in various ways)?The work has broader impacts due to the potentially significant role of SO clouds in determining the sensitivity of global climate to external forcing from greenhouse gas increases and other factors. Data from the campaign will be used to develop better representations of clouds in models used for weather prediction and climate impacts assessments. The data will be made available to the worldwide scientific community, thus the campaign has broader impacts by creating a community resource for basic science research. The work also promotes international scientific collaboration through its partnership with Australian colleagues. Summer internships are planned at the PIs' home institution to allow undergraduate students to participate in post-campaign data analysis, as well as outreach to K-12 students and the general public through regular newsletters and blogs, and an interactive "Ask SOCRATES" website. This project provides support and training to a postdoctoral researcher and a graduate student, thereby providing for the future workforce in this research area.

南大洋（SO），意为南半球高纬度的全球海洋，被誉为地球上风暴最多的地方，当之无愧。 SO 的偏远及其恶劣的条件严重限制了对其上方发生的大气过程的观测，包括沿南极锋移动的气旋中的云过程。然而，这些过程由于多种原因而引起人们的兴趣，其中包括SO云相对不受大陆和人为气溶胶的影响，因此该地区是研究原始条件下云行为的天然实验室。 SO 云还通过将入射阳光反射回太空，在地球的能量平衡中发挥着重要的冷却作用。有证据表明，这种降温对与热带辐合带相关的低纬度降雨分布具有长期影响，并且全球气候变化导致的SO云量变化将影响南半球的位置和强度。半球急流。我们对二氧化硫云过程缺乏了解的一个指标是气候模型模拟中发现二氧化硫云覆盖不足，同时海洋表面过度吸收阳光，进而可能导致气候敏感性估计的错误。 模拟云量的缺陷在沿 SO 风暴路径行进的锋面天气系统的寒冷、干燥区域的边界层和低对流层云（顶部低于 3 公里）中最为明显。该奖项资助的工作是更大的项目的一部分名为南大洋云、辐射、气溶胶、运输实验研究（苏格拉底）的实地活动。该活动的主要活动是部署由国家大气研究中心地球观测实验室维护的湾流 V (GV) 研究飞机。 GV 将以澳大利亚霍巴特为基地，多次飞行穿越南极锋线，收集 SO 云及其发生的气象条件的数据。 GV 配备了下投探空仪来记录周围的气象条件，雷达和激光雷达用于观察云层，以及安装在机翼上或位于入口后面的仪器来采样、收集和分析气溶胶和云颗粒（液滴和冰晶）。 SOCRATES 活动是对国际上和其他美国机构计划的 SO 活动的补充，包括在船舶和麦夸里岛（南纬 54 度的一个无人居住小岛）上进行的表面观测。该活动要解决的一个关键问题是相对丰富的SO 云中的过冷液态水 (SLW) 水滴和冰粒，因为 SLW 在 SO 云中比北半球的云中更普遍。 PI 假设，SO 云中 SLW 云滴冻结成冰颗粒的程度受到云上升气流的强度的调节，而不是受到冰成核颗粒（INP，液滴内触发冻结的颗粒）的可用性的调节。 PI 还试图确定上覆自由对流层气溶胶浓度与局部表面和边界层控制（包括降水和风速）的相对影响，以确定边界层云中液滴的浓度。该项目的工作特别侧重于了解SO 云中冰晶的形成，是确定与 SLW 液滴相比冰颗粒丰度相对较低是否是由于 INP 缺乏的必要步骤。 称为逆流虚拟冲击器（CVI）的专门安装在机翼上的入口用于收集云液滴和冰晶，并将它们与环境气溶胶和其他非云物质分离。 使用称为连续流扩散室 (CFDC) 的设备进行进一步处理，将 INP 与不利于冰形成的云凝核（CCN，水蒸气在其上凝结形成液滴的颗粒）分离。 收集 INP 并随后使用电子显微镜和 X 射线显微镜等实验室技术进行分析，以确定其成分和其他特性。在同一地区运行的澳大利亚研究船也收集了类似的数据。 这些数据与其他活动数据相结合，以解决以下问题：* INP 浓度是否可以预测云冰川作用的程度？* 来自底层海洋的海浪和自由对流层中的远程传输作为来源的相对作用是什么？ SO 云中的 INP？* INP 特征和丰度是否与地表海水成分（在研究船上测量）相关，包括有机物和生物活性？* SOCRATES 观测为次生冰形成过程的发生或不存在提供了哪些证据（即由其他冰粒以各种方式形成的冰粒）？由于二氧化硫云在确定全球气候对温室气体增加和其他因素造成的外部强迫的敏感性方面具有潜在的重要作用，这项工作具有更广泛的影响。 该活动的数据将用于在用于天气预报和气候影响评估的模型中更好地表示云。 这些数据将提供给全世界的科学界，因此该活动通过为基础科学研究创建社区资源而产生更广泛的影响。这项工作还通过与澳大利亚同事的伙伴关系促进国际科学合作。暑期实习计划在 PI 所在机构进行，让本科生参与活动后的数据分析，并通过定期通讯和博客以及互动式“询问苏格拉底”网站向 K-12 学生和公众进行宣传。 该项目为博士后研究员和研究生提供支持和培训，从而为该研究领域的未来劳动力提供支持。

项目成果

Observations and Modeling of Rime Splintering in Southern Ocean Cumuli

南大洋积云雾凇分裂的观测和模拟

• DOI: 10.1029/2021jd035479
• 发表时间: 2021-12
• 期刊: Journal of Geophysical Research: Atmospheres
• 作者: Lasher‐Trapp, Sonia;Scott, Emma L.;Järvinen, Emma;Schnaiter, Martin;Waitz, Fritz;DeMott, Paul J.;McCluskey, Christina S.;Hill, Thomas C. J.
• 通讯作者: Hill, Thomas C. J.

Observations of clouds, aerosols, precipitation, and surface radiation over the Southern Ocean: An overview of CAPRICORN, MARCUS, MICRE and SOCRATES

南大洋云、气溶胶、降水和表面辐射的观测：CAPRICORN、MARCUS、MICRE 和 SOCRATES 概述

• DOI: 10.1175/bams-d-20-0132.1
• 发表时间: 2020-11
• 期刊: Bulletin of the American Meteorological Society
• 影响因子: 8
• 作者: McFarquhar, Greg M.;Bretherton, Chris;Marchand, Roger;Protat, Alain;DeMott, Paul J.;Alexander, Simon P.;Roberts, Greg C.;Twohy, Cynthia H.;Toohey, Darin;Siems, Steve;et al
• 通讯作者: et al

The Labile Nature of Ice Nucleation by Arizona Test Dust

亚利桑那试验尘埃冰核的不稳定性质

• DOI: 10.1021/acsearthspacechem.9b00304
• 发表时间: 2020-01
• 期刊: ACS Earth and Space Chemistry
• 影响因子: 3.4
• 作者: Perkins, Russell J.;Gillette, Samantha M.;Hill, Thomas C.;DeMott, Paul J.
• 通讯作者: DeMott, Paul J.

Ship-based measurements of ice nuclei concentrations over the Arctic, Atlantic, Pacific and Southern oceans

北极、大西洋、太平洋和南大洋冰核浓度的船基测量

• DOI: 10.5194/acp-20-15191-2020
• 发表时间: 2020-12-08
• 期刊: Atmospheric Chemistry and Physics
• 影响因子: 6.3
• 作者: A. Welti;E. Bigg;P. DeMott;Xi;a Gong;a;M. Hartmann;M. Harvey;S. Henning;P. Herenz;T. Hill;Blake Hornblow;C. Leck;M. Löffler;C. McCluskey;A. M. Rauker;J. Schmale;C. Tatzelt;M. van Pinxteren;F. Stratmann
• 通讯作者: F. Stratmann

Empirical formulation for multiple groups of primary biological ice nucleating particles from field observations over Amazonia

根据亚马逊流域实地观测得出的多组初级生物冰成核颗粒的经验公式

• DOI: 10.1175/jas-d-20-0096.1
• 发表时间: 2021-04
• 期刊: Journal of the Atmospheric Sciences
• 影响因子: 3.1
• 作者: Patade, Sachin;Phillips, Vaughan T.;Amato, Pierre;Bingemer, Heinz G.;Burrows, Susannah M.;DeMott, Paul J.;Goncalves, Fabio L.;Knopf, Daniel A.;Morris, Cindy E.;Alwmark, Carl;et al
• 通讯作者: et al