Arctic Environment Arctic Ocean

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Arctic Environment (Arctic Ocean)
Ocean surface pCO2 workshop Tsukuba, 13-15
January, 2004
List of Groups, who have relevant datasets in the
Nordic-Arctic Oceans UoB, BCCR Truls
Johannessen, Richard Bellerby, Are Olsen,
Abdirahman M. Omar and Ingunn Skjelvan UGOT Leif
Anderson, Melissa, Agneta, Caroline UMPC Maria
Hood and Liliane Merlivat MI Jón
Ólafsson Others Taro, Schnaider, Kelley etc.
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Chemical Oceanography University of Bergen at
GFI and the Bjerknes Centre for Climate
Research-BCCR) Prof. Truls Johannessen, tracers
and inorg. C-cycle Prof. Christoph Heinze,
C-cycle modeling Dr. Richard Bellerby, inorg.
C-cycle Dr. Yoshie Kasajima, physical
oceanography (mixing) Dr. Stud. Caroline Kivimäe,
inorg. C-cycle Engineer, Solveig Kringstad,
tracers and inorg. C-cycle Senior engineer, Craig
Neill, tracers and inorg. C-cycle Dr. Are Olsen,
inorg. C-cycle Dr. Anders Olsson, tracers Dr.
Stud. Abdirahman M. Omar, inorg. C-cycle Master
Stud., Gisle Nondal, inorg. C-cycle Dr. Ingunn
Skjelvan (station M, C-cycle) Senior Research
Assistant, Fredrik Svendsen Research Assistant,
Kelly Brown
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New G. O. Sars
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The Neill system, a NOAA Design and UoB production
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In general, two types of convection, eddies and
classic convection
Convection spread the tracer into a broad depth
band in the centre of the gyre May 97
(observation of a SCV) and June 2002
May 97
June 2002
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Eddy in the Greenland Sea (75º 21N 0º 34W)
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Eddy in the Greenland Sea (75º 21N 0º 34W) and
outside
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The role of convection in the Greenland Sea for
CO2
What about the Greenland Sea?
Model the daily evolution of properties in the
surface water over a year,
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The role of convection in the Greenland Sea for
CO2
Time evolution of dissolved inorganic carbon and
d13CCT in the central Greenland Sea.
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Barents Sea response to increased atmospheric CO2
between 1967 and 2001 JOURNAL OF GEOPHYSICAL
RESEARCH, VOL. 108, NO. C12, 3388,
doi10.1029/2002JC001628, 2003
Barents Sea pCO2 measurements Triangles
Eastwind 1967 (Kelley, 1970) Circles R/V Håkon
Mosby 2000 and 2001 (henceforth 2001)
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The response of the Barents Sea between 1967 and
2001 that of the atmosphere

• the increase is
• uniformly distributed
• throughout the BS,
• indicating advection

Seawater pCO2 (µatm)
pCO2 1967
oceanic pCO2 increase 42 µatm atmospheric pCO2
increase 47 µatm
SST ( C)
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Summary of the results

• Barents Sea surface water pCO2 has increased by
  42 µatm between 1967 and 2001, due to
  uptake of excess CO2.
• The increase is uniformly distributed in the
  Barents Sea, suggesting that the excess
  carbon advected into the area.
• The pCO2 increase in the Barents Sea between
  1967 and 2001 is comparable to the
  corresponding increase in the atmosphere i.e. the
  oceanic increase tracks that of the atmosphere.
  

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CO2 fluxes associated with deep water formation
by sea ice and brine production. Implications for
uptake of CO2 in the Arctic Ocean.

• surface ocean takes up CO2 from the
• atmosphere, equilibration time is in years.

Air-sea exchange of CO2

• deep water formation transfers CO2 from
• the surface to deep ocean where its stored
• for 1000s of years.

• it is therefore important to study processes
  that
• govern carbon concentration of deep water as
• it forms.

• Deep water forms by
• open ocean convection e.g. in Greenland
• and Iceland Seas
• sea-ice formation and brine rejection on the
• Arctic shelves.

Paper III investigates the governing processes
for carbon in brine-enriched shelf water (BSW).
Obtained from http//www.urova.fi/home/arktinen/f
eed_pdf/Anderson.pd
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• Sea ice formation and subsequent brine rejection
  produce Brine-enriched Shelf Water (BSW) in
  Storfjorden
• (e.g. Schauer, 1995 Quadfasel et al., 1988)

• A coastal polynya accounts for most of ice and
  brine formation (Skogseth and Haugan, 2003)

• Outflow of BSW from Storfjorden enter the Arctic
  Ocean through Fram Strait (Quadfasel et al.,
  1988).

• Data from both the source water, the newly
  formed BSW, and old BSW provided the
  opportunity
• to identify and quantify modifications of
  carbon in BSW relative to the source water.

Barents- øya
Greenland
Spitsbergen
Edgeøya
S t o r f j o r d e n
Norway
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Analysis of the processes governing carbon
concentration in BSW
BSW S 35, T TFreezing

• BSW contain more carbon than its source.

• Thus it must be due to air-sea exchange during
  winter.

• The formation and outflow of BSW represents a
  way of transfer of carbon from
• the surface ocean-atmosphere system i.e. a
  carbon pump

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Winter time carbon uptake and fluxes for
Storfjorden
From volumes of BSW, modeled for 1998 - 2001 by
Skogseth and Haugan (2003), and the
carbon enhancement due to air-sea exchange, the
winter carbon uptake (WCU) in Storfjorden is
computed WCU ?CTN aVBSW 1.61011 g C

• In 1998-2001, the polynya accounted for
• 10 of the total area of Storfjorden
• 58 of the total ice production (Skogseth and
  Haugan, 2003)

Therefore, it is assumed that the polynya
accounted for 58 of the total brine production.
CO2 flux in ice covered region 0.42WCU/Area 6
g C m-2 yr-1
CO2 flux in the polynya 0.58WCU/Area 73.5 g C
m-2 yr-1
ice
ice
ice
Storfjorden
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Summary of the results

• Air-sea exchange of CO2 during winter and
  remineralization of organic matter during summer
  govern the
• carbon concentration in BSW.

• Due to the above two processes, BSW which flow
  out from Storfjorden into the deep ocean contain
  more
• carbon than its source. Thus, BSW transfers
  carbon from the surface-ocean atmosphere system
  into the deep
• ocean.

• Winter time air-sea CO2 flux is 12 times higher
  for the polynya region, compared to seasonally
  ice covered
• regions of Storfjorden.

• Winter time uptake of atmospheric CO2 of
  501012 g C can be associated with the formation
  of seasonal ice
• in the Arctic Ocean, provided that
  Storfjorden air-sea CO2 fluxes are applicable in
  the whole region.

• This uptake may triple by 2100, due to an
  increase of the area where seasonal ice forms and
  polynya activity.

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Interannual variability in the wintertime airsea
ux of carbondioxide in the northern North
Atlantic, 19812001 Are Olsena,b,, Richard G.J.
Bellerbyb,a, Truls Johannessena,b, Abdirahman M.
Omarb,a, Ingunn Skjelvana,b a Geophysical
Institute, University of Bergen, All!egaten 70,
5007 Bergen, Norway b Bjerknes Centre for Climate
Research, University of Bergen, All!egaten 55,
5007 Bergen, Norway Received 22 March 2002
received in revised form 28 February 2003
accepted 13 August 2003
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Methods
Paper III

• An empirical relationship between fCO2 and SST
  was computed based on data obtained at a number
  of research cruises. This applies to the northern
  North Atlantic in Oct.-Mar.
• Monthly fields of fCO2 were computed from fields
  of SST by this relationship.
• Monthly fields of the air-sea CO2 flux were
  computed.

winters, 1981-2001 119 pcs.
By courtesy of Are Olsen
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Summary of the results

• Winter time air-sea CO2 flux over the northern
  North Atlantic is 0.08 Gt C, with an interannual
  variability of 7 .

• Locally and on monthly time scales, the
  interannual variability is higher, typically 20
  40 .

• Changes in wind speed and atmospheric fCO2
  account for most of the interannual flux
  variability.

• However, equally important changes in oceanic
  fCO2 may be obscured by the use of a constant
  relationship
• with SST, highlighting the need for a better
  assessment of marine CO2.

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Future perspectives