Extreme spikes in DMS flux double estimates of biogenic sulfur export from the Antarctic coastal zone to the atmosphere

A. L. Webb*, M. A. van Leeuwe, D. den Os, M. P. Meredith, H. J. Venables, J. Stefels

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

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Abstract

Biogenic dimethylsulfide (DMS) is a significant contributor to sulfur flux from the oceans to the atmosphere, and the most significant source of aerosol non sea-salt sulfate (NSS-SO42-), a key regulator of global climate. Here we present the longest running time-series of DMS-water (DMSW) concentrations in the world, obtained at the Rothera Time-Series (RaTS) station in Ryder Bay, West Antarctic Peninsula (WAP). We demonstrate the first ever evaluation of interseasonal and interannual variability in DMSW and associated flux to the atmosphere from the Antarctic coastal zone and determine the scale and importance of the region as a significant source of DMS. Impacts of climate modes such as El Nino/Southern Oscillation are evaluated. Maximum DMSW concentrations occurred annually in January and were primarily associated with sea-ice break-up. These concentrations resulted in extremely high (up to 968 mu mol m(-2) d(-1)) DMS flux over short timescales, which are not parameterised in global-scale DMS climatologies. Calculated DMS flux stayed above the aerosol nucleation threshold of 2.5 mu mol m(-2) d(-1) for 60% of the year. Overall, using flux determinations from this study, the total flux of DMS-sulfur from the Austral Polar Province (APLR) was 1.1 Tg sulfur yr(-1), more than double the figure suggested by the most recent DMS climatologies.

Original languageEnglish
Article number2233
Number of pages11
JournalScientific Reports
Volume9
DOIs
Publication statusPublished - 19-Feb-2019

Keywords

  • SEA-ICE
  • DIMETHYL SULFIDE
  • MARGUERITE BAY
  • OCEANIC PHYTOPLANKTON
  • SOUTHERN-OCEAN
  • CLIMATE-CHANGE
  • GAS-EXCHANGE
  • RYDER BAY
  • ROSS SEA
  • WEST

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