Assessing Atmospheric Impacts of the Hunga Tonga-Hunga Ha'apai Volcanic Eruption and Using It as a Natural Experiment to Evaluate an Earth System Model

评估洪加汤加-洪加哈派火山喷发的大气影响并将其用作评估地球系统模型的自然实验

• 批准号: 2302458
• 负责人: Mark Flanner
• 金额: $ 51.88万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-01 至 2026-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2302458&HistoricalAwards=false
• 关键词: Assessing; Atmospheric; Impacts; Hunga; Tonga

Volcanic eruptions can affect weather and climate through several different mechanisms. For example, highly explosive eruptions, like that of Mt. Pinatubo in 1991, often produce sulfur-containing droplets and particles high in Earth’s atmosphere. There, these aerosols scatter sunlight back to space and can cool global climate for more than a year. On January 15, 2022, the Hunga Tonga–Hunga Ha'apai volcano erupted explosively in the South Pacific. Satellite observations showed that the eruption introduced surprisingly little sulfur to the atmosphere but injected an enormous amount of water vapor into the stratosphere, about 10-20 miles above Earth’s surface. Water vapor is a greenhouse gas and is particularly effective at warming climate when it is in the stratosphere, where only trace amounts of water generally exist. The eruption increased the total global stratospheric water vapor content by roughly 10%, representing the largest single-source injection of stratospheric water vapor ever observed from space, and furthermore this excess water could persist for 5-10 years. The Tonga eruption therefore represents an unprecedented natural experiment on Earth’s atmosphere. This investigation will use observations and modeling to assess the atmospheric impacts of the eruption, including its effects on Earth’s energy budget via alterations to the amount of sunlight and infrared energy absorbed and emitted by the planet. The investigators will assess how the eruption affected stratospheric temperatures, circulation patterns throughout the atmosphere, and the annual ozone hole formation over Antarctica, which may be perturbed through chemical and physical mechanisms related to the eruption. More broadly, this project will evaluate how well an Earth System Model captures the observed perturbations to Earth’s atmosphere in the years following the eruption and identify improvements to models that remedy any deficiencies that are found.In a broader sense, this project will contribute to an improved understanding of the atmospheric and climate impacts and risks to global society posed by large volcanic eruptions, particularly those that erupt beneath the ocean surface like the 2022 Tonga event. Records of past volcanic activity recorded in ice cores from Greenland and Antarctica indicate that eruptions ten times more powerful than the 2022 Tonga event occur roughly once every 625 years, with potentially severe impacts on civilization. The scientists involved in this project will conduct simulations of such events to explore their potential impacts. They will also adapt an Earth System Model so that it can be used more readily by the scientific community to comprehensively study climate impacts from volcanic eruptions, for example by improving the ability of the model to track and isolate the influences of volcanic water vapor, sulfur, and ash. Finally, the investigators will train and mentor a Ph.D. student for this project and expand the material on volcano-climate interactions presented in the graduate- and undergraduate-level courses.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.

火山喷发可以通过多种不同的机制影响天气和气候，例如，像 1991 年皮纳图博山那样的高度爆炸性喷发，通常会在地球大气层中产生含硫液滴和颗粒，这些气溶胶将阳光散射回太空。 2022 年 1 月 15 日，洪加汤加-洪加哈派火山喷发。卫星观测表明，这次喷发向大气中引入的硫量极少，但却向距地球表面约 10 至 20 英里的平流层注入了大量的水蒸气。在气候变暖的平流层中，通常只存在微量的水，这次喷发使全球平流层水蒸气含量增加了大约10%，这是最大的单源注入。从太空观测到的平流层水蒸气最多，而且这种过量的水可能会持续 5-10 年，因此，汤加火山喷发是对地球大气层的一次前所未有的自然实验，这项调查将利用观测和建模来评估火山喷发对大气的影响。包括通过改变地球吸收和发射的阳光和红外能量对地球能源预算的影响。研究人员将评估火山喷发如何影响平流层温度、整个大气的环流模式以及年度。南极洲上空臭氧空洞的形成，可能会受到与火山喷发相关的化学和物理机制的扰动。更广泛地说，该项目将评估地球系统模型在火山喷发后几年内捕捉到的地球大气扰动的情况，并确定改进措施。弥补发现的任何缺陷的模型。从更广泛的意义上讲，该项目将有助于更好地了解大型火山喷发，特别是那些在地下喷发的火山喷发对全球社会造成的大气和气候影响和风险格陵兰岛和南极洲冰芯中记录的过去火山活动记录表明，大约每 625 年发生一次比 2022 年汤加事件强大十倍的火山喷发，这可能对文明造成严重影响。参与该项目的人员将对此类事件进行模拟，以探索其潜在影响。他们还将调整地球系统模型，以便科学界更容易地使用它来全面研究气候影响。最后，研究人员将为该项目培训和指导一名博士生，并扩展材料。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。