Collaborative Research: EUREC4A-iso--Constraining the Interplay between Clouds, Convection, and Circulation with Stable Isotopologues of Water Vapor

合作研究：EUREC4A-iso——用水蒸气的稳定同位素体约束云、对流和环流之间的相互作用

• 批准号: 1937780
• 负责人: Simon de Szoeke
• 金额: $ 45.36万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-11-15 至 2024-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1937780&HistoricalAwards=false
• 关键词: Collaborative; Research; EUREC4A; iso; Constraining

Low-level clouds over tropical oceans cool the earth's climate by reflecting sunlight back to space. In global climate models (GCMs) these clouds generally amplify greenhouse gas-induced warming, as warming reduces cloud cover and allows more sunlight to reach the surface, causing further warming. But the strength of this amplification varies considerably from model to model and contributes substantially to the large range of warming estimates from GCMs. Moreover, cloud simulations from fine-scale, small-domain models which explicitly represent low clouds show less reduction in cloudiness than GCMs, which represent low clouds indirectly through parameterizations. On the other hand, cloud cover in the fine-scale models can reduce significantly with warming if the low clouds organize into clusters, a behavior not captured in GCMs.Recent research suggests that low cloud sensitivity differences among GCMs, and between GCMs and fine-scale models, can be understood in terms of the various ways in which models balance the moistening and drying effects of precipitation, surface evaporation, turbulent mixing, and cloud updrafts and downdrafts over tropical oceans. This research has identified specific balances which lead to higher or lower cloud sensitivity to warming, allowing tests against observations to be made. New observations are required to conduct such tests.Work supported under this award collects observations of the isotopic composition of water vapor, raindrops, and sea water to examine the moistening and drying processes that determine low cloud properties and sensitivities. Ordinary water (H2O) consists of two hydrogen atoms and one oxygen-16 atom, but some water molecules contain atoms of the heavier isotopes deuterium, oxygen-17, and oxygen-18. Water molecules containing heavier isotopes condense more readily and evaporate more sluggishly than ordinary H2O. Thus air samples with the same humidity can have different concentrations of heavy isotopes depending on the processes through which that humidity came about. For instance, if the humidity level is set by the mixing of dry air above the cloud layer and moist air near the ocean surface, concentrations of heavy isotopes will generally be higher than if the same humidity level is established by condensing water out of moist low-level air. Water isotope data is collected as part of a field campaign with the acronym EUREC4A, for Elucidating the Role of Clouds-Circulation Coupling in Climate. EUREC4A is a multinational campaign led by the Max Planck Institute in Germany and the Laboratoire de Meteorologie Dynamique in France, with a deployment based in Barbados from January 20th to February 20th 2020. This award supports isotope sampling from two ships, an aircraft, and the Barbados Cloud Observatory. Data collection and analysis is combined with model simulations in a variety of ways. Much of the work involves models which simulate the distinct behaviors of heavy isotopes so that direct comparisons with isotopic data can be made.The research has broader impacts due to its potential for reducing uncertainty in GCM-based estimates of the severity of future climate change. The EUREC4A campaign also provides an opportunity to enhance international scientific collaboration, and the project provides field experience for two graduate students. Outreach to the public is conducted during the campaign through a blog, and the PIs have partnered with the New Mexico Museum of Natural History and Science to perform outreach through programs including the Young Explorers Summer Science Camp and the Junior Docent Program.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

热带海洋上空的低层云层通过将阳光反射回太空来冷却地球的气候。 在全球气候模型（GCM）中，这些云通常会放大温室气体引起的变暖，因为变暖减少了云层覆盖，并允许更多的阳光到达地表，导致进一步变暖。 但是这种放大的强度在不同的模型之间有很大的差异，并且对GCM的大范围变暖估计有很大的贡献。此外，云模拟从细尺度，小域模式，明确表示低云显示减少云量比GCM，这代表低云间接通过参数化。 另一方面，如果低云组织成团，则细尺度模式中的云量会随着变暖而显著减少，这是GCM中没有捕捉到的行为。最近的研究表明，GCM之间以及GCM和细尺度模式之间的低云敏感性差异可以根据模式平衡降水、地面蒸发、湍流混合、以及热带海洋上空的云上升气流和下降气流。 这项研究已经确定了导致云对变暖的敏感性更高或更低的特定平衡，允许对观测进行测试。 该奖项支持的工作收集了对水蒸气、雨滴和海水的同位素组成的观测，以检查决定低云特性和敏感性的增湿和干燥过程。 普通的水（H2O）由两个氢原子和一个氧-16原子组成，但有些水分子含有较重的同位素氘，氧-17和氧-18的原子。含有较重同位素的水分子比普通的H2O更容易凝结，蒸发也更缓慢。 因此，具有相同湿度的空气样本可以具有不同的重同位素浓度，这取决于湿度产生的过程。 例如，如果湿度水平是由云层上方的干燥空气和海洋表面附近的潮湿空气混合而成的，那么重同位素的浓度通常会高于通过从潮湿的低层空气中冷凝出水而建立的相同湿度水平。水同位素数据的收集是一个缩写为EUREC 4A的实地活动的一部分，用于阐明云-环流耦合在气候中的作用。 EUREC 4A是一项由德国马克斯普朗克研究所和法国气象动力学研究所领导的多国活动，于2020年1月20日至2月20日在巴巴多斯部署。 该奖项支持从两艘船，一架飞机和巴巴多斯云观测站进行同位素采样。 数据收集和分析以各种方式与模型模拟相结合。大部分工作涉及模拟重同位素的不同行为的模型，以便与同位素数据进行直接比较。这项研究具有更广泛的影响，因为它有可能减少基于GCM的未来气候变化严重程度估计的不确定性。 EUREC 4A活动还提供了加强国际科学合作的机会，该项目为两名研究生提供了实地经验。 在活动期间通过博客向公众进行宣传，PI与新墨西哥州自然历史和科学博物馆合作，通过包括青年探索者暑期科学营和少年讲师计划在内的计划进行宣传。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Isotopic measurements in water vapor, precipitation, and seawater during EUREC4A

EUREC4A 期间水蒸气、降水和海水的同位素测量

• DOI: 10.5194/essd-2022-3
• 发表时间: 2021
• 期刊: Earth system science data
• 影响因子: 11.4
• 作者: Bailey, A.;Aemisegger, F.;Villiger, L.;Los, S. A.;Reverdin, G.;Meléndez, E. Q.;Acquistapace, C.;Baranowski, D. B.;Böck, T.;Bony, S.
• 通讯作者: Bony, S.

Sub-cloud rain evaporation in the North Atlantic winter trade winds derived by pairing isotopic data with a bin-resolved microphysical model

通过将同位素数据与箱分辨微物理模型配对得出的北大西洋冬季信风中的亚云降雨蒸发

• DOI: 10.5194/acp-23-12671-2023
• 发表时间: 2023
• 期刊: Atmospheric Chemistry and Physics
• 影响因子: 6.3
• 作者: Sarkar, Mampi;Bailey, Adriana;Blossey, Peter;de Szoeke, Simon P.;Noone, David;Quiñones Meléndez, Estefanía;Leandro, Mason D.;Chuang, Patrick Y.
• 通讯作者: Chuang, Patrick Y.