Chemistry of reactive gases in the Arctic sea ice and atmosphere
The Arctic is warming on average twice as rapidly as the rest of the planet, resulting in substantial declines in sea ice coverage and other changes in the Arctic environment with implications for the global climate system. One major limitation in our understanding of these changes is a relative lack of environmental data in the high Arctic, particularly in winter. These challenges motivate the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC), the largest multinational scientific expedition ever undertaken in the Arctic. Operating from the German icebreaker R/V Polarstern as it drifts with sea ice over the period from Fall 2019-Fall 2020, scientists from more than 17 nations will collect a wide range of physical, chemical, and biological measurements of the surface ocean and sea ice, surface trace gas and energy flow, bulk meteorological parameters, vertical profiling, and aerosol and cloud characterization. This project is one element of MOSAiC and focuses on questions surrounding reactive halogen sources and their impacts on the atmospheric chemistry of ozone, mercury, reactive nitrogen and volatile organic compounds (VOCs); it will provide the most northerly, complete annual record of these gas compounds ever obtained. This study is being conducted by scientists from the US, UK, Netherlands, France, and Australia in collaboration with the broader MOSAiC collaboration. High time resolution observations (minutes to 1.5 hours) will be acquired for atmospheric ozone (by a UV absorption monitor; commercial TEI), gaseous elemental mercury (GEM; commercial Tekran), non-methane hydrocarbons (NMHC), oxygenated VOCs (oVOCs), halogenated VOCs (hVOCs) (all with a custom-made enrichment system and gas chromatography and spectroscopy), oxidized nitrogen species (differentiated into nitric oxide (NO) and nitrogen dioxide (NO2)), and the sum of reactive gaseous nitrogen (NOy); custom-built chemiluminescence analyzer). Data will be thoroughly quality controlled, including by intercomparison with NOAA and the University of East Anglia, UK, calibration scales. Data will be shared with MOSAiC partners and submitted to the Arctic Data Center for free access and use by the research community.