The Role of Sea Ice in the Production and Release of Volatile Organic Compounds (VOCs)

Unicellular algae produce VOCs in response to the environmental conditions within the brine channels of sea ice. This production is likely to be in response to the elevated salinities in these channels. Grazing pressure from zooplankton, advection of under ice water, organic matter decay (within the water column and sediments) and other factors will contribute to VOC production. These VOCs may be lost to the atmosphere throughout the year but the softening and melting of sea ice leads to significant releases of these VOCs. These emissions may be linked to ozone depletion events. We have developed a novel approach to VOC analysis using SPME (solid phase micro-extraction) fibres and can identify and quantify >60 compounds in a single analysis. The primary goal of this SFG application is to validate this SPME approach in preparation for multi-year study. Secondary goals include the measurement of VOCs in sea water under the ice, open sea water near Longyearbyen, soil and sediment gases from the substrate (including vegetated regions if available) and the air. This project will take place in Svalbard using sea ice collected from nearby (exact location depends on the sea ice development this year) using the gas chromatograph - mass spectrometer at UNIS configured for SPME VOC analyses. Ice cores will be collected down to the water, sectioned in the field and returned to the laboratory in sealed jars. The ice will be melted in these sealed jars and the VOCs purged with a stream of nitrogen gas. The VOCs will be absorbed on to an SPME fibre and transferred to the inlet of the GC where they will be desorbed due to the heat of the injector. The separated VOCs will be identified and quantified by the MS. Additional samples will be collected on SPME fibres from the secondary media to validate the wide applicability of the method. The data will be collated and published and used to demonstrate the approach for a much larger multi-year project to study the annual cycles.