Exchange fluxes of climate-relevant trace gases off the Western AntaRctic Peninsula (EWARP)

• Applicants: Dr. Thomas Badewien; Professor Dr. Hermann W. Bange, since 9/2022; Professor Oliver Wurl, Ph.D.
• Subject Area: Oceanography
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 462668354

The Western Antarctic Peninsula (WAP) comprises a highly productive ecosystem and is arguably one of the most rapidly changing regions under the effects of global warming. Natural temporal-spatial variability in the form of sea ice seasonality, cross-shelf transport of warm circumpolar waters and submesoscale eddies have a pronounced effect in the chemical and biological setting of the WAP. Hence, environmental changes such as accelerated glacial melting, reduced sea ice coverage and increased UVlight availability might have vast effects in the biogeochemical cycles of the region. However, the specific direction of change is still unclear, mostly due to paucity of data resulting from the difficulty of access. Climate-relevant trace gases belong to highly relevant, yet under-studied compounds in Polar Regions, and in particular, in the WAP. Not only lack of data coverage, but also of a detailed under-standing of the controlling mechanisms for the transfer of gases from the mixed layer to the atmosphere makes it challenging to estimate their overall emissions to the atmosphere. The mixed layer and atmosphere are separated by naturally occuring surface films controlling exchange processes. Hence, to this date it is not clear whether the WAP is a source or sink of trace gases. We propose to conduct an ambitious multidisciplinary study, which aims to quantify the production and exchange fluxes of trace gases in coastal and open ocean waters of the WAP. In particular, we aim to: i) assess the major production pathways of CH4, N2O, DMS, and CO in the Bransfield Strait sub-region, ii) elucidate the controlling mechanisms for their transfer across the ML-SML-A interfaces and their variability during the spring-summer transition, and iii) decipher at what extent sub-mesoscale processes affect trace gas cycling and SML properties. To this end, we propose to use moored observations, seasonal samplings at a fixed-point station, and a process study including highlyresolution physical, chemical and biological measurements with autonomous platforms (e.g. remotely operated catamaran and drifters). The proposed project will provide insights on the main controls of the emissions of trace gases to the atmosphere in the WAP, and will help future model studies to improve the representation of the effects of accelerated glacial melt in ocean-atmosphere models.

• DFG Programme: Infrastructure Priority Programmes
• Subproject of: SPP 1158: Infrastructure area - Antarctic Research with Comparative Investigations in Arctic Sea Ice Areas
• International Connection: Chile
• Cooperation Partner: Dr. Juan Höfer
• Ehemaliger Antragsteller: Damian Leonardo Arévalo-Martínez, Ph.D., until 9/2022