Probing the roles of reactive iodine and bromine in Arctic halogen chemistry

在该项目中，研究小组将重新分析以前收集的、但未经审查的来自作为北极观测网络组成部分部署的15个浮标的活性卤素光谱数据，以研究溴和碘之间可能的协同增效作用的程度及其对北极臭氧消耗的影响。研究小组将主要关注碘化学对臭氧消耗的影响，因为最近的出版物表明，碘在北极的卤素和臭氧化学中的作用可能比以前假设的更为关键。由于该项目中使用的数据已经存在于以前的浮标光谱仪观测中，因此这项工作的重点是重新分析数据，将数据与其他观测数据进行比较，并进行建模实验，以研究北极地区可能受碘影响的大气化学。在这项拟议的工作中要检验的主要假设是，虽然活性溴仍然在北极大部分地区的臭氧消耗化学中占主导地位，但与活性碘的化学协同作用可能会加速这一进程，特别是在某些地区。该项目的成功可能会对北极大气化学界、更广泛的气候研究界和公众产生强烈的积极影响。在之前的NSF资助项目中，该项目主要关注溴化学，研究小组利用多轴差分光学吸收光谱作为美国国家科学基金会北极观测网络的一部分，利用自由浮动浮标进行的MAX-DOAS观测，确定溴是北极地区主要的臭氧消耗活性卤素。新的研究表明，碘可能比以前假设的更重要。现在将重新分析这些现有的测量结果，重点是碘化学，并与最近在北极地区对卤素的观测结果进行比较。碘和溴含量的季节性和区域性分布将通过地面合作测量进行量化和验证，一维化学模型将用于确定碘和溴在浮标位置臭氧消耗化学中的相对作用。一名博士后研究人员和一名本科生将在本项目期间获得支持。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。

In this project the research team will reanalyze previously gathered but unexamined reactive halogen spectroscopy data from fifteen buoys deployed as a component of the Arctic Observing Network in order to study the magnitude of possible synergies between bromine and iodine and their impact on Arctic ozone depletion. The research team will focus primarily on the impact of iodine chemistry on ozone depletion as recent publications indicate that iodine may have a more critical role in halogen and ozone chemistry in the Arctic than previously assumed. As the data to be used in this project already exists from previous buoy spectrometer observations, this work focuses on reanalyzing the data, comparing the data to other observations, and conducting modeling experiments to examine the potential iodine-influenced atmospheric chemistry in the Arctic. The main hypothesis to be tested in this proposed work is that while reactive bromine still dominates ozone depletion chemistry for most of the Arctic, chemical synergies with reactive iodine may accelerate the process, particularly in some regions. Success in this project is likely to have a strong positive impact on the Arctic atmospheric chemistry community, the broader climate research community, and the public.In the previous NSF-funded project, which focused primarily on bromine chemistry, the research team utilized multiple-axis differential optical absorption spectroscopy (MAX-DOAS) observations from free-floating buoys as a part of the NSF Arctic Observing Network and determined that bromine is the dominant ozone depleting reactive halogen in the Arctic. New research indicates that iodine may have a more critical role than previously assumed. These existing measurements will now be reanalyzed with a focus on iodine chemistry and compared to recent observations of halogens within the Arctic. Seasonal and regional distributions of iodine and bromine amounts will be quantified and validated with collaborative ground-level measurements and a 1-D chemical model will be used to determine the relative role of iodine and bromine in ozone depletion chemistry at buoy locations. A postdoctoral researcher and an undergraduate student will be supported during this project.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.