International Polar Year 2007–2008 - WMO

cluded: How much CO 2 is absorbed (and released) by
the Southern Ocean and how sensitive is the Southern
Ocean carbon “sink” to climate change? How is the absorption
of CO 2 changing the chemistry of the Southern
Ocean, and what impact will acidification have
on organisms and ecosystems? What is the distribution
and supply of iron and other trace elements and
isotopes, and what do they tell us about the sources
and sinks of CO 2 and the control of primary productivity?
What processes control the concentrations of
geochemical species used as proxies for past environmental
conditions, and what are the implications for
interpretation of past climate?
IPY observations
Biogeochemical measurements (including oxygen,
nutrients, carbon and tracers) were made along
most of the hydrographic lines shown in Fig. 2.3-1a.
IPY-GEOTRACES work was carried out on a number
of additional sections shown in Fig. 2.3-6, including
process studies in the Amundsen Sea, in the subant-
arctic and polar frontal zones to the south and east of
Australia and New Zealand (e.g. Ellwood, 2008; Bowie
et al., 2009) and in the sea ice zone (van der Merwe et
al., 2009) as well as in the Atlantic sector and Drake
Passage (Fahrbach and de Baar, 2010). The trace metal
work required clean sampling techniques, which were
widely used in the Southern Ocean for the first time
during IPY. Water samples were collected using nonmetallic
rosettes and cables, with analyses conducted
in special clean containers using agreed protocols
(Johnson et al., 2007; Fahrbach and de Baar, 2010).
Research highlights
Knowledge about the carbon cycle of the
Southern Ocean has increased significantly during
IPY. Nevertheless, most of these data have still to
be included in global studies to further improve
estimates of interior ocean storage of anthropogenic
CO 2 and the air-sea exchange of CO 2 that were
determined in studies (Sabine et al., 2004; Takahashi
et al., 2009) made before IPY. Le Quéré et al., (2007)
Fig. 2.3-6.
GEOTRACES transects
and process cruises in
the Southern Ocean
during IPY.
(Map: Andrew Bowie)
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