The Influence of Climate Variability and Change on Stratospheric Intrusions of Ozone over North America

气候变率和变化对北美上空臭氧入侵平流层的影响

• 批准号: 1756958
• 负责人: John Albers
• 金额: $ 31.23万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-12-01 至 2023-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1756958&HistoricalAwards=false
• 关键词: Influence; Climate; Variability; Change; Stratospheric

Ground-level ozone is harmful to human health, and ozone-producing activities must sometimes be curtailed to avoid dangerous ozone concentrations. Efforts to maintain safe ozone levels by limiting production are complicated by the presence of ozone from sources other than local human activity, as higher levels of this "background" ozone necessitate more stringent production caps. The background concentration poses a challenge for air quality management as background levels vary from place to place and also change over time. Thus the need to manage and mitigate ground-level ozone motivates research on the behavior of the background and the fundamental processes that govern its variability in time and space.A significant portion of the background ozone comes from the stratosphere, where ozone is produced naturally by ultraviolet sunlight and can be transported over great distances. The stratosphere extends upward from roughly the flight level of long-distance air travel and is thus well separated from ground-level ozone production and impacts. But ozone-rich air can descend into the troposphere during stratospheric intrusions, which occur as a result of Rossby wave breaking. In this process the large-scale flow becomes strongly sheared and stratospheric air forms filaments which extend and fold into the troposphere and mix with ambient air. The stratospheric contribution implies that the ozone background can be influenced by several forms of atmospheric and climate variability that are known to affect the stratosphere, including El Nino/Southern Oscillation (ENSO) events, the Northern Annular Mode (NAM), and the Quasi-Biennial Oscillation (QBO).Research performed here seeks to understand the processes which control the location and amount of stratospheric ozone entering the troposphere over North America. Two factors are considered, the first of which is the amount of ozone present in the lowest layer of the stratosphere where it can be mixed into the troposphere by intrusions. The amount of ozone in this reservoir is controlled by processes including the equator-to-pole overturning circulation of the stratosphere which can potentially be influenced by ENSO, NAM, and QBO variability. The second factor is north-south shifts of the North Pacific jet stream and accompanying storm track, which modulate the frequency and location of Rossby wave breaking events that produce intrusions over western North America. Such jet shifts are known to occur as a consequence of ENSO and NAM variability. The research is conducted through a combination of observational analysis, working from satellite data and reanalysis products, and computer simulations using the Whole Atmosphere Community Climate Model (WACCM, developed as part of the Community Earth System Model).As noted above, the work has broader impacts due to the need to inform mitigation actions to address the health impacts of ground-level ozone pollution. In addition to pollution concerns the work has relevance to several forms of surface weather that are affected by stratospheric intrusions. In particular, deep intrusions can modulate thunderstorm activity and increase surface winds leading to enhanced wildfire occurrence.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.

地面臭氧对人类健康有害，有时必须减少产生臭氧的活动，以避免危险的臭氧浓度。通过限制生产来维持安全的臭氧水平的努力由于来自当地人类活动以外的其他来源的存在而变得复杂，因为这种“背景”臭氧需要更严格的生产上限。 背景集中构成了空气质量管理的挑战，因为背景级别在地点之间都不同，并且随着时间的流逝而变化。 因此，需要管理和减轻地面臭氧的需求激发了对背景行为的研究以及控制时间和空间变化的基本过程。背景臭氧的很大一部分来自平流层，在平流层中，紫外线自然会通过紫外线产生臭氧，并且可以在巨大的距离上运输。 平流层从长距离空中旅行的飞行水平大致向上延伸，因此与地面臭氧的生产和影响良好。 但是，富含臭氧的空气可以在平流层侵入期间降落到对流层中，这是由于Rossby波的破裂而发生的。 在此过程中，大规模的流动变得强烈剪切，并延伸到对流层并与环境空气混合。平流层的贡献意味着臭氧背景可以受到已知会影响平流层的几种形式的大气和气候变异性的影响 美国。 考虑了两个因素，第一个因素是平流层最低层中存在的臭氧量，可以通过侵入将其混合到对流层中。 该储层中的臭氧量受到包括平流层的赤道至底倾循环的过程控制，这可能会受到ENSO，NAM和QBO变异性的影响。 第二个因素是北太平洋喷气流和伴随的风暴轨道的南北变化，这调节了罗斯比波浪破坏事件的频率和位置，这些事件导致北美西部的入侵。已知这种喷气转移是由于ENSO和NAM变异性而发生的。这项研究是通过观察性分析，卫星数据和重新分析产品的工作以及使用整个大气层社区气候模型（作为社区地球系统模型的一部分开发而开发的）的计算机模拟来进行的。如上所述，由于需要为缓解措施解决地面层面污染的健康影响，因此需要更广泛的影响。 除污染外，该工作还与受平流层入侵影响的几种形式的表面天气有关。 特别是，深层入侵可以调节雷暴活动并增加表面风，从而导致野火的发生增强。该奖项反映了NSF的法定任务，并且使用基金会的知识分子优点和更广泛的影响评估标准，认为值得通过评估来获得支持。

项目成果

Dynamics of ENSO-driven stratosphere-to-troposphere transport of ozone over North America

• DOI: 10.5194/acp-22-13035-2022
• 发表时间: 2022-10
• 期刊: Atmospheric Chemistry and Physics
• 影响因子: 6.3
• 作者: J. Albers;A. Butler;A. Langford;D. Elsbury;Melissa Breeden

The response of the North Pacific jet and stratosphere-to-troposphere transport of ozone over western North America to RCP8.5 climate forcing

北美西部上空的北太平洋急流和平流层到对流层臭氧输送对 RCP8.5 气候强迫的响应

• DOI: 10.5194/acp-23-5101-2023
• 发表时间: 2023
• 期刊: Atmospheric Chemistry and Physics
• 影响因子: 6.3
• 作者: Elsbury, Dillon;Butler, Amy H.;Albers, John R.;Breeden, Melissa L.;Langford, Andrew O'Neil
• 通讯作者: Langford, Andrew O'Neil

The spring transition of the North Pacific jet and its relation to deep stratosphere-to-troposphere mass transport over western North America

北太平洋急流的春季转变及其与北美西部上空深层平流层到对流层质量输送的关系

• DOI: 10.5194/acp-21-2781-2021
• 发表时间: 2021
• 期刊: Atmospheric Chemistry and Physics
• 影响因子: 6.3
• 作者: Breeden, Melissa L.;Butler, Amy H.;Albers, John R.;Sprenger, Michael;Langford, Andrew O'Neil
• 通讯作者: Langford, Andrew O'Neil

Subseasonal predictability of the North Atlantic Oscillation

• DOI: 10.1088/1748-9326/abe781
• 发表时间: 2021-04-01
• 期刊: ENVIRONMENTAL RESEARCH LETTERS
• 影响因子: 6.7
• 作者: Albers, John R.;Newman, Matthew
• 通讯作者: Newman, Matthew

Subseasonal prediction of springtime Pacific–North American transport using upper-level wind forecasts

使用高层风预报对春季太平洋-北美运输进行次季节预测

• DOI: 10.5194/wcd-2-433-2021
• 发表时间: 2021
• 期刊: Weather and Climate Dynamics
• 作者: Albers, John R.;Butler, Amy H.;Breeden, Melissa L.;Langford, Andrew O.;Kiladis, George N.
• 通讯作者: Kiladis, George N.