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

平流层臭氧消耗是一个众所周知的现象，主要是因为南极臭氧空洞以及对生态系统和人类健康不利影响的关切。 但臭氧消耗也发生在北极平流层，在卫星数据中可以看到10%至20%的减少，例如2000年至2005年和1979年至1984年的平均值之间的差异。 与南极不同的是，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，北极的臭氧消耗有两个明显的最大值，一个在平流层上部35公里和45公里之间（大约5毫巴到1毫巴），另一个在平流层下部10公里和15公里之间（大约200到100毫巴）。 研究所和其他机构的研究已提供了令人信服的证据，证明南极臭氧洞已使平流层和对流层的气候和大气环流发生了重大变化。 这些变化包括平流层冷却和南极洲周围西风从平流层向南移动到地球表面。 然而，由于缺乏研究工作和卫星对北极上空臭氧估算的差异，还没有确定北极臭氧消耗对气候和环流的类似影响，这里的工作通过将三个卫星数据集与独立的辐射传输代码和全大气共同体气候模型相结合，一个大气环流模型，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式从三个观测数据集中发现的臭氧浓度计算辐射加热率，以确定加热的大小和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，其中将三个数据集中的臭氧浓度强加于WACCM模拟，使用WACCM的指定化学版本。 将利用仅限于10毫巴以上和以下平流层的臭氧变化进行实验，以确定平流层上部臭氧变化对平流层下部的影响程度，以及高层和低层加热对对流层的影响程度。 这些实验的动机是双重最大结构的臭氧消耗。 最后，WACCM将与交互式气相化学相结合，以便该模式能够模拟内部臭氧损失，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异和变化的驱动机制，北极气候变化与生态系统的社会相关影响有着广泛的联系，冰冻圈和北极的人类活动。 此外，北极上空大气环流的变化可对北方中纬度地区的天气和气候产生重大影响。 此外，该项目还为一名研究生提供支助和培训，从而培养在这一领域工作的下一代科学家。

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.