Collaborative Research: Using SOCRATES Datasets to Improve Simulations of Clouds, Aerosols and their Climate Impacts

合作研究：使用 SOCRATES 数据集改进对云、气溶胶及其气候影响的模拟

• 批准号: 1660538
• 负责人: Stephan Fueglistaler
• 金额: $ 23.57万
• 依托单位: Princeton 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: 2017-06-15 至 2021-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1660538&HistoricalAwards=false
• 关键词: Collaborative; Research; Using; SOCRATES; Datasets

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.This project is a component of the 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 is based in Hobart, Australia and makes 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. Work supported here uses data collected in the SOCRATES campaign to improve the representation of SO clouds and cloud-aerosol interactions in climate and weather models. Several possible reasons for the cloud deficiencies are addressed, including deficiencies in the representation of cloud microphysics leading to overly rapid freezing of supercooled liquid water (SLW) cloud droplets, excessive precipitation from shallow cumulus clouds, errors in the representation of small-scale turbulent motions and their effects on the distribution of cloud water, and inaccurate representation of aerosols and their role as condensation nuclei for liquid droplets and nucleating particles for cloud ice. Much of the activity in the campaign is focused on the abundance of SLW in SO clouds, which are less glaciated than their Northern Hemisphere counterparts (i.e. they contain more very cold liquid droplets and fewer ice particles), and work in this project uses model simulations to understand this difference.Two categories of models are used, global atmospheric models and large-eddy simulation (LES) models. Global models include the Community Atmosphere Model version 6 (CAM6), developed by and for the research community and hosted at the National Center for Atmospheric Research, and the Atmospheric Model version 4 (AM4), developed by the Geophysical Fluid Dynamics Laboratory. The LES model is the System for Atmospheric Modeling (SAM), developed by researchers at the State University of New York at Stony Brook and the Colorado State University. For the global models, a "nudged meteorology" strategy is used to facilitate comparisons between observations and model simulations. In this strategy the model is subjected to forcing terms which constrain it to remain close wind and temperature values produced by operational weather forecasting centers. The goal is to reproduce the large-scale meteorological conditions in which campaign observations were made, so that the cloud and aerosol observations from the campaign can be reasonably compared to their simulated counterparts. The project uses the understanding developed from these comparisons, and from the LES modeling, to develop a representation for ice nucleating particles in CAM6. The work has broader impacts due to its potential value for improving models used for weather prediction and future climate projections. The work on model improvement also has broader impacts for the scientific research community, as CAM6 and AM4 are widely used tools for scientific research. The nudged meteorology simulations are available for community use as part of the long-term online archive of data collected in the campaign, along with the meteorological analyses used to nudge the models and ancillary cloud and sea surface observations from satellites. In addition to the broader impacts of the work performed, the project provides support and training for two postdocs, thereby providing for the development of the scientific workforce in this research area. The PIs also contribute to campaign outreach activities including a SOCRATES blog.

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，这种冷却对与间热接收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。在边界层和沿SO暴风雨轨迹行驶的冷干燥部门的边界层和低对流层云中最明显的云覆盖物中的缺陷最为明显。该项目是南部海洋云，辐射，气溶胶，气雾剂，运输实验研究（Socrates（Socrates）的组成部分。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总部位于澳大利亚霍巴特，在南极前沿进行多次飞行，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活动中进行了补充，包括在船上和麦格理岛上进行的表面观察，这是南部54度的一个无人居住的小岛。这里支持的工作使用苏格拉底运动中收集的数据来改善气候和天气模型中So云和云 - 大气互动的表示。解决了云缺乏症的几个可能原因，包括在云微物理学表示的缺陷，导致过度冷冻的超冷液化（SLW）云滴，过度降水，浅层积云云的降水量，浅层液化运动及其对型号的速有频道和群体的影响的造成的误差云层的液滴和成核颗粒。 运动中的许多活动都集中在So云中的SLW丰富性上，而SLW的云层不及北半球对应物（即它们包含更多非常冷的液体液滴和更少的冰粒），并且在此项目中使用模型模型来了解模型的模型类别，模型的两个模型和大气模型模型和大型模型和大型模型（les）模型（les）模型（les）。 全球模型包括由研究社区开发的社区大气模型6（CAM6）（CAM6），并在国家大气研究中心举办，以及由地球物理动力学实验室开发的大气模型版本4（AM4）。 LES模型是由纽约州立大学斯托尼·布鲁克大学和科罗拉多州立大学的研究人员开发的大气建模系统（SAM）。 对于全球模型，使用“裸露的气象”策略来促进观察和模型模拟之间的比较。 在此策略中，模型受到迫使其限制的术语，以保持近距离风能和由操作天气预测中心产生的温度值。 目的是重现进行竞选观察的大规模气象条件，以便与竞选活动的云和气溶胶观察结果可以合理地与他们的模拟同行相比。 该项目利用从这些比较和LES建模中得出的理解来开发CAM6中冰核颗粒的表示形式。由于其用于改善用于天气预测和未来气候预测的模型的潜在价值，这项工作具有更大的影响。 关于模型改进的工作也对科学研究界产生了更广泛的影响，因为CAM6和AM4是科学研究的广泛使用的工具。 轻度的气象模拟可用于社区使用，作为活动中收集的数据的长期在线档案的一部分，以及用于推动卫星的模型和辅助云和海面观测的气象分析。除了执行工作的更广泛影响外，该项目还为两个博士后提供了支持和培训，从而为该研究领域的科学劳动力提供了发展。 PI还为包括苏格拉底博客在内的活动推广活动做出了贡献。

项目成果

Reduction of Bias from Parameter Variance in Geophysical Data Estimation: Method and Application to Ice Water Content and Sedimentation Flux Estimated from Lidar

减少地球物理数据估算中参数方差的偏差：激光雷达估算冰水含量和沉积通量的方法及应用

• DOI: 10.1175/jas-d-19-0106.1
• 发表时间: 2020
• 期刊: Journal of the Atmospheric Sciences
• 影响因子: 3.1
• 作者: Bolot, Maximilien;Fueglistaler, Stephan
• 通讯作者: Fueglistaler, Stephan

Tropical Water Fluxes Dominated by Deep Convection Up to Near Tropopause Levels

热带水通量由深对流主导直至接近对流层顶水平

• DOI: 10.1029/2020gl091471
• 发表时间: 2021
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Bolot, Maximilien;Fueglistaler, Stephan
• 通讯作者: Fueglistaler, Stephan

Simple Spectral Models for Atmospheric Radiative Cooling

大气辐射冷却的简单光谱模型

• DOI: 10.1175/jas-d-18-0347.1
• 发表时间: 2020
• 期刊: Journal of the atmospheric sciences
• 影响因子: 3.1
• 作者: Jeevanjee, Nadir;Fueglistaler, Stephan
• 通讯作者: Fueglistaler, Stephan