Collaborative Research: Field Measurements of Clouds and Aerosol Particles over the Southern Ocean in SOCRATES

合作研究：苏格拉底对南大洋上空云和气溶胶颗粒的现场测量

• 批准号: 1660509
• 负责人: Lynn Russell
• 金额: $ 18.8万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 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 2021-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1660509&HistoricalAwards=false
• 关键词: Collaborative; Research; Field; Measurements; Clouds

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 funded under this award contributes to SOCRATES by measuring aerosol and cloud hydrometeor properties, specifically addressing three questions (from the proposal summary):1) What are the chemical and physical properties of sub-micron and coarse-mode aerosol particles in the region, and how do they relate to cloud condensation nuclei (CCN, particles around which cloud droplets form), INP, and cloud properties?2) What fraction of SO condensed water remains supercooled as a function of temperature, and can this be related to a dearth of INPs?3) What is the role of biological aerosol particles in cloud formation over the SO?These questions are addressed through in-situ air sampling using inlets available on the GV. Sampling of cloudy air uses a specialized inlet known as a counterflow virtual impactor (CVI), which separates cloud droplets and ice crystals from smaller aerosol particles and other non-cloud material. Droplets and ice crystals are heated in the CVI to evaporate their water substance and the resulting vapor is measured with a laser hygrometer to determine total condensed water content. Once the water is evaporated the droplets and ice are reduced to their nucleating particles (referred to as residual particles), which are counted and sized using an aerosol spectrometer. A fluorescence-based spectrometer is used to separately count and size biological particles so that their role in nucleation can be assessed. Residual particles are collected on slides for laboratory analysis using electron and X-ray microscopy that can determine morphology, composition, and mixing state. A key question in the analysis is the hygroscopicity of the particles, meaning their ability to absorb water vapor and thus serve as CCN. Additional measurements from wing-mounted supercooled liquid probes are used to estimate the ratio of SLW to ice content in the clouds.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. A further contribution to basic research is the development of a clean-in-place system for the CVI inlet, which will improve the reliability of the CVI for future users, particular in salty marine environments. Campaign outreach to K-12 students and the general public is conducted through regular newsletters and blogs, and an interactive "Ask SOCRATES" website. Events in which campaign videos, microscope images of cloud particles, and aerosol samples collected during the campaign are presented to the general public, are also planned. This award provides support and training to a graduate student and funds the participation of a second student in the campaign, thereby contribution to the development of the future workforce in this research area.

南大洋（So）意味着南半球高纬度的全球海洋，作为地球上最暴风雨的地方享有当之无愧的声誉。 SO及其不受欢​​迎的条件的远程性在其上方发生的大气过程严重有限，包括沿南极前沿行驶的旋风中的云过程。然而，这些过程是出于多种原因而引起的，包括这样的事实，即云相对不受大陆和人为气溶胶的影响，因此该地区是对原始条件下云行为进行研究的自然实验室。因此，云在地球的能量平衡中也发挥了重要的冷却作用，通过反射回到太空的阳光。有证据表明，这种冷却对与间热收敛区相关的低纬度降雨的分布有远距离影响，并且由于全球气候变化而导致的多云的变化将影响南半球喷气流的位置和强度。我们对SO云过程缺乏理解的一个指标是，在气候模型模拟中发现的云覆盖不足，这伴随着海面过度吸收阳光，这又可能导致气候灵敏度估计值的错误。 在边界层和较低的对流层云中，模拟云层的缺陷最为明显，在沿So Storm Track行驶的冷干燥扇区中的较低的干燥，干燥的部门。该奖项基于该奖项的作品是较大的现场活动的一部分，标题为“南方海洋云，辐射，气溶胶，运输实验研究（Socrates）”。该运动的主要活动是部署由国家大气研究中心的地球观察实验室维护的湾流V（GV）研究飞机。 GV将总部位于澳大利亚的霍巴特，并在南极前沿进行多次飞行，以收集有关云层和发生气象条件的数据。 GV配备了Dropsondes，可记录环境气象条件，雷达和激光雷达，以观察云，并安装在机翼上或放置在入口后面以进行样品，收集和分析气溶胶和云颗粒（液滴和冰晶体）。苏格拉底运动与计划在国际和其他美国机构计划的SO活动相辅相成同行。 PI假设SLW云滴在冰颗粒中冻结到冰颗粒的程度更为强烈地通过云上升的活力来调节云，而不是通过冰核颗粒的可用性（Inps，液滴中的粒子，触发冷冻的液滴中的颗粒）。 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 funded under this award contributes to SOCRATES by measuring aerosol and cloud hydrometeor properties, specifically addressing three questions (from the proposal summary):1) What are the chemical and physical properties of sub-micron and coarse-mode该区域中的气溶胶颗粒与云凝结核（CCN，周围形成云液滴形成的颗粒），INP和云特性如何相关？2）如此凝聚的水的哪一部分仍然过冷的函数，作为温度的函数，这可以与inps的最低作用有关？使用GV上可用的入口。 多云空气的采样使用专门的入口，称为逆流虚拟撞击器（CVI），该入口将云滴和冰晶与较小的气溶胶颗粒和其他非云材料分开。将液滴和冰晶体在CVI中加热以蒸发其水物质，并用激光湿度计测量所得的蒸气，以确定总冷凝水含量。 一旦蒸发水，将液滴和冰还原为成核颗粒（称为残留颗粒），这些颗粒使用气溶胶光谱仪对其进行计数和大小。 基于荧光的光谱仪用于分别计数和尺寸的生物颗粒，以便可以评估它们在成核中的作用。 使用电子和X射线显微镜在载玻片上收集残留颗粒，以确定形态，组成和混合状态。分析中的一个关键问题是颗粒的吸湿性，这意味着它们吸收水蒸气并因此用作CCN的能力。使用机翼安装过冷的液体探针进行的其他测量可用于估计云中SLW与冰分含量的比率。由于SO云在确定全球气候与温室气体的外部强迫和其他因素的敏感性中的潜在重要作用，因此具有更大的影响。该活动的数据将用于在天气预测和气候影响评估的模型中开发更好的云表示。这些数据将提供给全球科学界，因此，通过为基础科学研究创造社区资源，该活动会产生更广泛的影响。 对基础研究的另一个贡献是开发CVI入口的清洁系统，这将提高CVI对未来用户的可靠性，尤其是在咸海洋环境中。 与K-12学生和公众的竞选活动是通过常规新闻通讯和博客进行的，以及互动的“ Ask Socrates”网站。还计划将活动视频，云颗粒的显微镜图像以及在活动期间收集的气溶胶样品的显微镜图像提交给公众。 该奖项为研究生提供了支持和培训，并为第二名学生的参与提供了支持，从而为该研究领域的未来劳动力的发展做出了贡献。

项目成果

Cloud‐Nucleating Particles Over the Southern Ocean in a Changing Climate

云——气候变化中南大洋上空的成核粒子

• DOI: 10.1029/2020ef001673
• 发表时间: 2021
• 期刊: Earth's Future
• 作者: Twohy, Cynthia H.;DeMott, Paul J.;Russell, Lynn M.;Toohey, Darin W.;Rainwater, Bryan;Geiss, Roy;Sanchez, Kevin J.;Lewis, Savannah;Roberts, Gregory C.;Humphries, Ruhi S.
• 通讯作者: Humphries, Ruhi S.

Cloud Microphysical Effects of Aerosol Particle Sources and Marine Boundary Layer Processes

气溶胶颗粒源和海洋边界层过程的云微物理效应

• 发表时间: 2017
• 期刊: UC San Diego Electronic Theses and Dissertations
• 作者: Sanchez, Kevin J

Measured Constraints on Cloud Top Entrainment to Reduce Uncertainty of Nonprecipitating Stratocumulus Shortwave Radiative Forcing in the Southern Ocean

• DOI: 10.1029/2020gl090513
• 发表时间: 2020-11
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: K. Sanchez;Gregory Charles Roberts;M. Diao;L. Russell

Organic composition of three different size ranges of aerosol particles over the Southern Ocean

南大洋上空三种不同尺寸范围的气溶胶颗粒的有机成分

• DOI: 10.1080/02786826.2020.1845296
• 发表时间: 2021
• 期刊: Aerosol Science and Technology
• 影响因子: 5.2
• 作者: Saliba, G.;Sanchez, K. J.;Russell, L. M.;Twohy, C. H.;Roberts, G. C.;Lewis, S.;Dedrick, J.;McCluskey, C. S.;Moore, K.;DeMott, P. J.
• 通讯作者: DeMott, P. J.

Measurement report: Cloud processes and the transport of biological emissions affect southern ocean particle and cloud condensation nuclei concentrations

测量报告：云过程和生物排放物的传输影响南大洋颗粒和云凝结核浓度

• DOI: 10.5194/acp-21-3427-2021
• 发表时间: 2021
• 期刊: Atmospheric Chemistry and Physics
• 影响因子: 6.3
• 作者: Sanchez, Kevin J.;Roberts, Gregory C.;Saliba, Georges;Russell, Lynn M.;Twohy, Cynthia;Reeves, Michael J.;Humphries, Ruhi S.;Keywood, Melita D.;Ward, Jason P.;McRobert, Ian M.
• 通讯作者: McRobert, Ian M.