Biology and the Carbon Cycle
Numerous model studies have suggested that polar regions are very suscep-
tible to changes in climate. The in-situ measurements of DMS in air and
water made from the USCGC Polar Sea during the transect of the Arctic Ocean
basin have significantly increased the data available on DMS source strengths
and distribution in this sensitive region. Together with the concurrent meas-
urements of CCN and other aerosol and chemical properties of the Arctic
atmosphere, they provide a unique opportunity to investigate the possible
link between DMS, CCN and clouds.
We collected water samples for DMS analysis at the science stations either
with Niskin bottles at various depths or from the ship's uncontaminated sea-
preconcentrating on adsorbent cartridges and then thermally desorbing into a
gas chromatograph with a sulfur chemiluminescence detector. DMS concentra-
tions in surface seawater samples collected between 24 July and 3 September
ranged from less than 0.1 to 9.1 nM/L. The concentration range was similar
to that observed during the 1991 Oden expedition. Maximum concentrations
were observed along the ice edge and minimum concentrations (below the
detection limit of 0.1 nM/L) at the North Pole.
We collected atmospheric DMS samples using a portable sampler, always
Distribution of atmo-
spheric dimethyl sul-
fide concentrations
during the AOS-94
expedition.
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