Collaborative Research: Peroxide Measurements and Modeling for the Pacific Atmospheric Sulfur Experiment

作为太平洋大气硫实验的一部分，将在基里巴斯圣诞岛赤道太平洋逆风上空的海洋边界层中对气相过氧化氢和甲基氢过氧化物进行测量。 PASE是一项在2007年8月至9月在NSF/NCAR C-130飞机上进行的远程低海洋对流层海洋硫化学的综合研究。 在与格鲁吉亚技术建模工作的合作，化学机制，包括散装气溶胶化学，云滴，气相化学，参数化的气体气溶胶质量传输和物质通量之间的自由对流层MBL和空气-海洋表面将实施的过氧化物数据的分析和解释。 该机制将包括卤素，特别是溴。 在PASE期间，硫物种预计将受到来自海洋的二甲基硫（DMS）通量及其随后的氧化的调节。 了解海洋含硫气体对新粒子产生、粒子生长、云凝结核以及气候的影响的关键是二甲基硫醚中二氧化硫、二甲基亚砜和硫酸盐的产生和归宿。 过氧化物是一种重要的含硫化合物云中氧化剂。 过氧化物的PASE测量和建模将提供气象驱动的材料通量和直接氧化剂，如羟基自由基（OH）和过氧化氢的约束。 这项工作还将限制可疑的氧化剂，如一氧化溴（BrO），一个潜在的重要DMS氧化剂在赤道太平洋在其预期的水平（0.05-0.5 ppt），但目前无法测量，更广泛的影响，研究生的教育和培训，本科生接触大气化学研究，和传播新的知识，大气化学，海洋气溶胶和气候。 知识转移将通过出版物和向其他科学家和公众介绍进行。

Measurements of gas phase hydrogen peroxide and methylhydroperoxide will be made in the marine boundary layer (MBL) over the equatorial Pacific upwind of Christmas Island, Kiribati, as part of the Pacific Atmospheric Sulfur Experiment (PASE). PASE is a comprehensive study of marine sulfur chemistry in the remote lower marine troposphere to be conducted in August-September 2007 on the NSF/NCAR C-130 aircraft. In collaboration with the Georgia Tech modeling effort, a chemistry mechanism including bulk aerosol chemistry, cloud droplets, gas phase chemistry, and parameterized gas-aerosol mass transport and material fluxes between the free troposphere-MBL and air-ocean surface will be implemented for the analysis and interpretation of the peroxide data. The mechanism will include halogens, bromine in particular. During PASE, sulfur species are expected to be regulated by the flux of dimethylsulfide (DMS) from the ocean and its subsequent oxidation. Critical to understanding the influence of marine sulfur gases on new particle production, particle growth, cloud-condensation nuclei and hence climate, are the production and fate of sulfur dioxide, dimethylsulfoxide, and sulfate from DMS. Peroxides are an important in-cloud oxidant of sulfur compounds. The PASE measurements and modeling of peroxides will provide constraints on meteorologically-driven material fluxes and on direct oxidants such as hydroxyl radical (OH) and hydrogen peroxide. This work will also constrain suspected oxidants like bromine monoxide (BrO), a potentially significant DMS oxidizer in the equatorial Pacific at its expected (0.05-0.5 ppt) but currently unmeasurable levels.Broader impacts of the study include education and training of graduate students, exposure of undergraduates to atmospheric chemistry research, and dissemination of new knowledge on atmospheric chemistry, marine aerosols and climate. Knowledge transfer will occur via publications and presentations to other scientists and the general public.