Scientific Program Overview (SPO): Southern Ocean Clouds, Radiation, Aerosol, Transport Experimental Study (SOCRATES)

科学计划概述 (SPO)：南大洋云、辐射、气溶胶、传输实验研究 (苏格拉底)

• 批准号: 1628674
• 负责人: Robert Rauber
• 金额: $ 5.25万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-11-01 至 2018-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1628674&HistoricalAwards=false
• 关键词: Scientific; Program; Overview; SPO; 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, accompanied by excessive solar absorbtion by the ocean surface which may in turn cause errors in estimates of climate sensitivity.This award funds planning and organizational activity for a field campaign titled Southern Ocean Clouds, Radiation, Aerosol, Transport Experimental Study (SOCRATES). The campaign itself is not yet funded, nor does NSF commit to funding it by making this award. By making the award NSF encourages the PIs to submit a set of proposals requesting support for each of the various campaign activities, which are reviewed collectively at a later date. This second round of reviews determines whether the campaign goes to the field and what elements of the campaign are supported by NSF.The campaign consists of a deployment of the Gulfstream V (GV), a research aircraft maintained by the Earth Observing Laboratory of the National Center for Atmospheric Research, based either in Hobart, Australia or Christchurch, New Zealand. The GV would fly south across the polar front, reaching the colder waters beyond 55 degrees South, to obtain observations of atmospheric boundary layer structure and vertical distributions of clouds and aerosols, including cloud condensation nuclei (CCN) and ice nucleating particles (INPs). 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 freezes at a given temperature is more strongly modulated by cloud updraft velocities than by availability of INPs. 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 SLW droplets in boundary layer clouds. The GV is equipped with radar and lidar for characterizing cloud properties as well as instruments which use inlets on the aircraft to collect and analyze the chemical and physical properties of aerosols and cloud droplets and ice particles. 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.As noted above, the work has broader impacts due to the potentially significant role of SO clouds in determining the response of global climate to increases in greenhouse concentrations, and the inadequacy of SO clouds in climate models used for future climate projections. In addition, a number of education and outreach activities are planned for the campaign. Graduate students are expected to participate in the campaign through the awards given to PIs for fieldwork, and other opportunities for graduate student fieldwork will also be proposed. Summer internships for post-campaign data analysis will also be considered as part of the review process conducted for the campaign. In addition, outreach to K-12 students and the general public is planned through regular newsletters and blogs, and an interactive "Ask SOCRATES" website through which campaign PIs answer questions on clouds and their role in the climate system.

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 SO 云过程缺乏了解的一个指标是气候模型模拟中发现的 SO 云覆盖不足，同时海洋表面过度吸收太阳光，进而可能导致气候敏感性估计错误。该奖项资助规划和组织题为南大洋云、辐射、气溶胶、运输实验研究（苏格拉底）的实地活动活动。 该活动本身尚未获得资助，美国国家科学基金会也没有承诺通过颁发此奖项来为其提供资金。通过颁发该奖项，NSF 鼓励 PI 提交一组提案，请求对每项活动提供支持，这些提案将在稍后进行集体审查。 第二轮审查决定该活动是否进入实地以及该活动的哪些内容由 NSF 支持。该活动包括部署湾流 V (GV)，这是一架由国家地球观测实验室维护的研究飞机大气研究中心，位于澳大利亚霍巴特或新西兰基督城。 GV将向南飞越极地锋，到达南纬55度以上较冷的水域，以获得大气边界层结构以及云和气溶胶垂直分布的观测结果，包括云凝结核（CCN）和冰核粒子（INP）。 该活动需要解决的一个关键问题是 SO 云中过冷液态水 (SLW) 水滴和冰粒的相对丰度，因为 SLW 在 SO 云中比北半球的云中更普遍。 PI 假设，在给定温度下 SLW 冻结的程度受云上升气流速度的影响比受 INP 可用性的影响更大。 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 SLW 液滴的浓度。 GV 配备了用于表征云特性的雷达和激光雷达，以及使用飞机上的入口收集和分析气溶胶、云滴和冰颗粒的化学和物理特性的仪器。 SOCRATES 活动是对国际上和其他美国机构计划的 SO 活动的补充，包括在船舶上和在南纬 54 度的一个无人居住小岛麦夸里岛进行的表面观测。如上所述，由于潜在的重大影响，这项工作具有更广泛的影响。 SO 云在确定全球气候对温室浓度增加的响应中的作用，以及用于未来气候预测的气候模型中 SO 云的不足。 此外，该活动还计划开展一些教育和外展活动。 研究生将通过向 PI 进行实地考察的奖励来参与该活动，并且还将提出研究生实地考察的其他机会。 活动后数据分析的暑期实习也将被视为活动审查过程的一部分。 此外，还计划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，活动 PI 可以通过该网站回答有关云及其在气候系统中的作用的问题。