Sulfur cycling at high latitudes: new discoveries and challenges

Institute of Nature and Environmental Technology, Kanazawa University, Japan

 

Title: Roles of sea ice in atmospheric sulfur cycles: Knowns and unknowns

 

Abstract: Sea ice plays a role in a variety of unique processes in dimethylsulfide (DMS) emission to the atmosphere and subsequent particle formation, while its impact on clouds and climate is yet poorly understood in terms of magnitude but also direction. In the framework of CIce2Clouds, we have been trying to bring together knowns and unknowns regarding sulfur cycles in polar regions from both atmospheric chemistry and sea-ice biogeochemistry perspectives. In the presentation, I will introduce the current understanding of DMS-related particle formation processes in both poles, and highlight the knowledge gaps that arise through our discussion.

 

Bigelow Laboratory for Ocean Sciences, USA

 

Title: An attempt to establish the relative contributions of local versus advected sources of DMS in the Central Arctic boundary layer

 

Abstract: During summer of 2020, as part of the MOSAiC expedition, near-continuous measurements of atmospheric dimethylsulfide (DMS) and DMS ocean-atmosphere flux obtained by eddy correlation (EC), were made from the ship bow tower at 20 meters height. Simultaneous, small footprint, short timescale, measurements of DMS fluxes were made using a dynamic chamber (DC) to quantify emission from specific surface types; explain variations in the footprint of the EC measurement and estimate the biogenic source strength of the fluxes through analysis of sea-ice and water concentrations of DMS and its precursor dimethylsulfoniopropionate (DMSP). The study illustrates the impact of the extensive meltwater layers that formed during this period, on the exchange of trace gases between ocean and atmosphere and demonstrates the substantial, possibly dominant, contribution of advected air masses to DMS concentrations over the Central Arctic.

 

Institute of Marine Sciences, Spain

 

Title: Introducing SCOR Working Group DMS-PRO: Developing resources for the study of Methylated Sulfur compound cycling PROcesses in the ocean

 

Abstract: Biogenic sulfur gases emitted by marine ecosystems, especially dimethylsulfide, critically influence the properties of aerosols and the radiative balance of the lower atmosphere in polar regions. Predicting these emissions at the relevant spatiotemporal scales is key to address the response of polar ecosystems to climate change and their feedbacks. However, predictive skill is currently limited by gaps in process-level understanding and by incomplete translation of existing mechanistic knowledge into numerical models. To address such challenges, we recently formed the SCOR Working Group 166 "DMS-PRO". The DMS-PRO working group will focus on compiling an open-access, comprehensive database of cycling rates of organic methylated sulfur compounds in seawater. In order to ensure the quality of the data, the working group plans to develop and publish standardized operating practices on the analytical procedures involved in the determination of these rates. An overarching aspiration of DMS-PRO is to stimulate research, build capacity, and establish an international, multidisciplinary community of practice on the oceanic cycle of methylated sulfur compounds that can share knowledge and skills with the broader oceanographic and Earth system science communities.

 

National Scientific and Technical Research Council, Argentina

 

Title: Introducing SCOR Working Group DMS-PRO: Developing resources for the study of Methylated Sulfur compound cycling PROcesses in the ocean

 

Abstract: Biogenic sulfur gases emitted by marine ecosystems, especially dimethylsulfide, critically influence the properties of aerosols and the radiative balance of the lower atmosphere in polar regions. Predicting these emissions at the relevant spatiotemporal scales is key to address the response of polar ecosystems to climate change and their feedbacks. However, predictive skill is currently limited by gaps in process-level understanding and by incomplete translation of existing mechanistic knowledge into numerical models. To address such challenges, we recently formed the SCOR Working Group 166 "DMS-PRO". The DMS-PRO working group will focus on compiling an open-access, comprehensive database of cycling rates of organic methylated sulfur compounds in seawater. In order to ensure the quality of the data, the working group plans to develop and publish standardized operating practices on the analytical procedures involved in the determination of these rates. An overarching aspiration of DMS-PRO is to stimulate research, build capacity, and establish an international, multidisciplinary community of practice on the oceanic cycle of methylated sulfur compounds that can share knowledge and skills with the broader oceanographic and Earth system science communities.