Linkages of Changes in Ozone to Arctic Climate Change in the Stratosphere and Troposphere

平流层和对流层臭氧变化与北极气候变化的联系

• 批准号: 1419667
• 负责人: Susan Solomon
• 金额: $ 59.25万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-15 至 2018-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1419667&HistoricalAwards=false
• 关键词: Linkages; Changes; Ozone; Arctic; Climate

Stratospheric ozone depletion is a well-known phenomenon, largely because of the Antarctic ozone hole and concerns over adverse effects on ecosystems and human health. But ozone depletion also occurs in the Arctic stratosphere, where reductions of 10% to 20% can be seen in satellite data, for example in differences between the means for years 2000 to 2005 and 1979 to 1984. Unlike the Antarctic, where a single ozone hole extends from altitudes below 15km to above 20km, Arctic ozone depletion has two distinct maxima, one in the upper stratosphere between 35km and 45km (roughly 5mb to 1mb) and one in the lower stratosphere between 10 and 15km (roughly 200 to 100mb). Research by the PIs and others has produced compelling evidence that the Antarctic ozone hole has produced substantial changes in the climate and atmospheric circulation of the stratosphere and troposphere. These changes include stratospheric cooling and a southward shift of the westerly winds around Antarctica that extends from the stratosphere to the Earth's surface. However, analogous climate and circulation impacts of the more subtle Arctic ozone depletion have not been identified, owing partly to lack of research effort and partly to discrepancies in the satellite-derived ozone estimates over the Arctic.Work conducted here addresses the impact of Arctic stratospheric ozone loss by combining three satellite derived datasets with stand-alone radiative transfer codes and the Whole Atmosphere Community Climate Model (WACCM), an atmospheric circulation model with a well-resolved stratosphere and optional stratospheric ozone chemistry. The first stage of the research is to use radiative transfer models to calculate radiative heating rates from the ozone concentrations found in the three observational datasets, in order to determine the magnitude of the heating and the extent to which differences in ozone concentrations yield differences in heating.These radiative heating calculations are followed by WACCM simulations in which the ozone concentrations from the three datasets are be imposed, using the Specified Chemistry version of WACCM. Experiments will be performed using ozone changes restricted to the stratosphere above and below 10mb, to determine the extent to which ozone changes in the upper stratosphere affect the lower stratosphere and the extent to which upper- and lower-level heating affect the troposphere. These experiments are motivated by the dual-maximum structure of the ozone depletion. Finally, WACCM will be integrated with interactive gas-phase chemistry, so that the model can simulate ozone loss internally, allowing the ozone chemistry to be affected by the temperature and circulation changes which it produces.The research seeks to develop a better understanding of the mechanisms driving for climate variability and change in the Arctic, and the Arctic climate change has broad linkages to societally-relevant impacts on ecosystems, the cryosphere, and human activities in the Arctic. Moreover, changes in atmospheric circulation over the Arctic can have substantial consequences for the weather and climate of the middle latitudes of the Northern Hemisphere. In addition, the project provides support and training for a graduate student, thereby providing for the next generation of scientists working in this area.

平流层臭氧消耗是一种众所周知的现象，主要是因为南极臭氧空洞以及对生态系统和人类健康的不利影响的关切。但是臭氧消耗也发生在北极平流层，在卫星数据中可以看到减少了10%到20%，例如在2000年至2005年和1979年至1984年的平均值之间的差异。在南极，一个臭氧空洞从15公里以下的高度延伸到20公里以上，而北极的臭氧消耗有两个明显的最大值，一个在35公里到45公里之间的平流层上层（大约5mb到1mb），另一个在10到15公里之间的平流层下层（大约200到100mb）。pi和其他机构的研究已经提供了令人信服的证据，证明南极臭氧空洞已经在气候和平流层和对流层的大气环流方面产生了实质性的变化。这些变化包括平流层变冷和南极洲周围从平流层延伸到地球表面的西风向南移动。然而，由于缺乏研究工作，以及由于卫星得出的北极臭氧估计值存在差异，尚未确定北极臭氧耗损对气候和环流的类似影响。这里开展的工作通过结合三个卫星衍生数据集和独立辐射传输代码和全大气群落气候模式（WACCM）来解决北极平流层臭氧损失的影响，WACCM是一个大气环流模式，具有良好的平流层分辨率和可选的平流层臭氧化学。研究的第一阶段是使用辐射传输模型，根据三个观测数据集中发现的臭氧浓度计算辐射加热速率，以确定加热的幅度以及臭氧浓度差异产生加热差异的程度。这些辐射加热计算之后是WACCM模拟，其中使用WACCM的特定化学版本，施加来自三个数据集的臭氧浓度。将利用仅限于10mb以上和10mb以下平流层的臭氧变化进行实验，以确定平流层上层臭氧变化对平流层下层的影响程度，以及高层和低层加热对对流层的影响程度。这些实验的动机是臭氧消耗的双最大值结构。最后，WACCM将与交互气相化学集成，使模型能够在内部模拟臭氧损失，使臭氧化学受到其产生的温度和环流变化的影响。该研究旨在更好地了解北极气候变率和变化的驱动机制，北极气候变化与生态系统、冰冻圈和北极人类活动的社会相关影响有着广泛的联系。此外，北极上空大气环流的变化可能对北半球中纬度地区的天气和气候产生重大影响。此外，该项目还为研究生提供支持和培训，从而为在该领域工作的下一代科学家提供支持。