Production and degradation of dimethylsulfide
(DMS) within lower-trophic level sympagic and
pelagic polar marine ecosystems:
A 1-D model study at Resolute Passage
H. Hayashida, E. Mortenson,
A. Monahan, & N. Steiner
M. Blais, V. Galindo, M. Gosselin, X. Hu, & CJ Mundy
Oceanic DMS in the Arctic
DMS is a climatically-active gas.
Oceanic DMS emissions are
important particularly to the Arctic
summer climate because:
1. Anthropogenic aerosol
concentrations are low.
2. DMS production occurs in
diverse ice-related habitats.
Adapted from
[Levasseur, 2013]
Research question & Approach
● Question: Does the DMS production within sea ice matter to the
oceanic DMS emissions in the Arctic?
● Approach: Numerical modelling
○ Sea ice thermodynamics (e.g. snow, melt pond, ice)
○ Ocean Physics (e.g. T, S, U, V)
○ Sea ice and ocean biogeochemistry:
■ Lower-trophic level marine ecosystem (NPZD)
■ Sulfur cycle (DMSP and DMS)
■ Carbon cycle (DIC and TA)
Talk by Eric Mortenson right after this talk.
Sympagic-pelagic sulfur cycle model schematic
Adapted from
[Mundy et al., 2014]
Study site: Resolute Passage
● Observations: Arctic-ICE 2010
● 1-D Model set-up:
○ Duration: 1 Feb. - 1 Sept. 2010
○ Time step: 10 min.
○ Domain: Snow (1 layer), melt
pond (1 layer), sea ice (10 layers),
and upper 50m ocean (50 layers)
○ Meteorological forcing: EC
weather station data at Resolute
airport
Results: Snow depth & ice thickness
Ice-free period
Results: Snow depth & ice thickness
Ice melt onset: Early-June
Snow melt onset: Late-May
Ice-free period
Results: Ice algae & phytoplankton
Ice-free period
Results: Ice algae & phytoplankton
Under-ice Phytoplankton (diatoms) bloom
Ice-free period
Bottom-Ice algae bloom
Open-water Phytoplankton (flagellates) bloom
Results: DMS
Ice-free period
Results: DMS at ice base & in seawater below
Peak associated with
the bottom-ice algae bloom
Ice-free period
Pulse of DMS from ice!
Peak associated with
the open-water bloom
Peak associated with
the under-ice bloom
Conclusion & Future work
Our model results suggest a substantial release of DMS from sea ice
into the water column, raising the concentration of seawater DMS
during the melt season.
DMS production in sea ice could play an important role in earlysummer Arctic aerosol production.
● Parameterization of DMS emissions from snow, ice, melt ponds,
and leads.
● Pan-Arctic 3-D regional modelling.