Interactions between Marine Biogeochemical Cycles,
Physics and Climate
Observations and Modelling of the Role of the Oceans
in the Earth System
Andrew Watson,
Ute Schuster,
Marie-José Messias,
Dorothee Bakker,
Gareth Lee,
Pete Brown*,
Justin Krijnen,
Elena Kozlova,
Peter Landschuetzer,
Neil Mackay,
Ben Mills,
Phil Underwood,
* also at the British Antarctic Survey,
Research Interests and Highlights
Many of the complex interactions between
the cycles of carbon,
nutrients and iron, ocean circulation and
global climate are not well understood.
Dramatic changes of global temperature,
the atmospheric carbon dioxide (CO2) content and ocean circulation
between glacial and interglacial periods demonstrate
the presence of such interactions.
The diverse projects carried out by our research group address questions
related to the biogeochemical role of the oceans in the Earth System,
the possible effects of climate change and ocean acidification on biogeochemical cycles and
the interactions of ocean biogeochemistry and physics,
using observations and modelling.
Transient tracers
(e.g. chlorofluorocarbons, CFCs, and sulfur hexafluoride, SF6)
are used as 'tracers' of ocean circulation, ocean mixing
(e.g. as part of DIMES)
and water mass formation.
Tracers are also used to quantify
the oceanic uptake of 'anthropogenic' carbon.
UEA scientists have carried out measurements of transient tracers and inorganic carbon parameters
across six deep vertical sections
in the Atlantic and adjacent Southern Ocean from 2008 to 2010.
This oceanographic research has the aim to quantify
storage and transport of natural and anthropogenic carbon
in these basins and is part of the
SOFI Oceans 2025
and
ANDREX programmes
(also see the UEA ANDREX
site).
This poster
provides details of the cruises we have participated in.
Deep sections from 2008 to 2010 with carbon and tracers by our team.
The dashed line has been done by US colleagues.
Also shown are Marie-José Messias, Andrew Brousseau and Elizabeth Jones during sea-going work and the RRS James Cook
in South Georgia.
Quantifying the North Atlantic carbon sink:
The uptake of the greenhouse gas carbon dioxide (CO2) by
individual oceanic regions and its year-to-year variation remain
poorly quantified.
Ute Schuster operates an autonomous CO2 instrument
on a voluntary observing ship (VOS)
between the UK and the Carribean since 2002
as part of the EU funded CAVASSOO,
CarboOcean
and
CarboChange
projects
and the UK Ocean Acidification Research Programme.
A major finding is important interannual variation
in the North Atlantic carbon dioxide sink (Schuster and Watson, 2007; Schuster et al., 2009).
CarboOcean data have been used to create
monthly pCO2 maps
for 2004 to 2006 for the North Atlantic Ocean,
using a neural network approach
(Telszewski et al., 2009).
In an article in
Science
Watson et al. (2009) describe how a coordinated network of instrumented
commercial ships has been used for quantification of the annual North Atlantic CO2 sink in 2005
to a precision of about 10%.
An
article in the Economist
calls for funding of such monitoring efforts.
Study of changes in the deep subtropical North Atlantic Ocean suggests that
anthropogenic
carbon is not accumulating at a steady rate across the water column
(Brown et al., 2010).
A pCO2 map for August 2005 (Telszewski et al., 2009)
Quantifying the Southern Ocean carbon sink:
Research with Mario Hoppema (Alfred Wegener Institute)
has highlighted the rapid transition of CO2-rich waters
below sea ice to a CO2 sink upon ice melt
(Bakker et al., 2008).
Both biological
carbon uptake
and calcium carbonate processes contribute to these changes in carbonate chemistry
during sea ice melt (Bakker et al., 2008; Jones et al., 2010).
Other research describes an ice melting hotspot with
high biological production in the northeastern Weddel Gyre (Geibert et al., 2010).
The SOIREE and EisenEx iron fertilisation experiments
have confirmed the occurrence of iron limitation
in large parts of the Southern Ocean
(Boyd et al., 2000; Watson et al., 2000; Bakker et al., 2001, 2005).
The impact of natural iron fertilisation on the marine carbon cycle was investigated in
CROZEX
near the Crozet Plateau (Bakker et al., 2007).
Elizabeth Jones has assessed the seasonal carbon cycle downstream
of South Georgia (Jones, 2010).
Ocean acidification in the Southern Ocean:
Nina Bednarsek and WHOI colleagues have developed a method for assessing
shell damage to marine pteropods.
Nina has used this method for an assessment of
the effect of ocean acidification on Antarctic pteropods (Bednarsek, 2010).
Pteropod limacina helicina from the Baltic Sea
(photo by Nina Bednarsek)
Ocean models are a tool for studying ocean transport
and water mass formation.
Nuno Nunes, a past group member, has compared
the formation of Antarctic Intermediate water at different
resolutions of the OCCAM model.
Christos Mitsis uses particle trajectories in
OCCAM
at 1/12th of a
degree resolution for an assessment of flow dynamics and eddy activity in the
Southern Ocean. This
movie
shows some of his tracer runs in OCCAM.
The research is part of DIMES.
Isopycnal surfaces and bottom topography in OCCAM
(by Christos Mitsis).
Click here
for an enlarged graph and further explanation.
Earth System Models may provide insight into the regulation
of biogeochemical cycles.
Several group members are developing
a description of ocean biogeochemistry and ocean physics
in GENIE,
a 3-dimensional Earth System Model (ESM), which can be used to
to study glacial to interglacial perturbations.
Ben Mills works with a simplified biogeochemical model to explore some of the
key processes that control atmospheric condidtions over geological time.
Ben is testing theories about the great oxidation event
(that occurred 2.4 billion years ago) and a possible secondary oxidation in the neoproterozoic.
Several past and present members of the research group,
from left to right:
Pete Brown,
Karel Castro-Morales (now at AWI),
Nina Bednarsek,
Dorothee Bakker (seated),
Alba Gonzalez-Posada (in Jan Kaiser's team),
Maciej Telszewski (now at IOCCP),
Ute Schuster,
James Clark (now at the University of Exeter),
Justin Krijnen,
Andrew Watson,
Christos Mitsis
Collaboration:
We closely collaborate with colleagues at the University of East Anglia,
(e.g. with
Jan Kaiser,
Karen Heywood,
Dave Stevens,
Peter Liss,
Corinne Le Quéré,
Andrew Manning,
Tim Jickells
),
with colleagues in the UK,
(e.g. at
the British Antarctic Survey,
Cefas ,
the National Oceanography Centre, Southampton,
Plymouth Marine Laboratory), and
with colleagues abroad
(e.g. at the Alfred Wegener Institute,
Woods Hole Oceanographic Institution,
the University of Bergen,
the Leibniz Institute and
LOCEAN).
We actively participate in data synthesis projects for marine carbon data, notably
CARINA
for deep ocean carbon data and
SOCAT (Surface Ocean CO2 Atlas)
for surface water fCO2 data.
These projects will ensure public access to and longterm storage of these valuable ocean carbon
data.
PhD studentships:
We are always looking for highly motivated PhD candidates with strong scientific interests.
Some of our projects are listed on the ENV studentship website .
Use Project Title/Keyword Search or Supervisor Search (left-hand bar) for finding projects.
We are also open to suggestions for new projects.
In general the best time for applications is early January, but some projects are available
at other times of the year.
Available funding varies.
If you are interested in doing PhD research in our team, contact
Andrew Watson,
Dorothee Bakker,
Ute Schuster,
or Marie-José Messias.
References on this page
Bakker, D.C.E., Y. Bozec, P.D. Nightingale, L.E. Goldson, M.J. Messias,
H.J.W. de Baar, M.I. Liddicoat, I. Skjelvan, V. Strass, and A.J. Watson (2005)
Iron and mixing affect biological carbon uptake in SOIREE and EisenEx,
two Southern Ocean iron fertilisation experiments.
Deep-Sea Research Part I, 52: 1001-1019, doi:10.1016/j.dsr.2004.11.015.
Bakker, D.C.E., Hoppema, M., Schröder, M., Geibert, W., Baar H. J.W. de (2008)
A rapid transition from ice covered CO2–rich waters to a biologically mediated
CO2 sink in the eastern Weddell Gyre. Biogeosciences, 5: 1373-1386.
http://www.biogeosciences.net/5/1373/2008/bg-5-1373-2008.html
Bakker, D.C.E., M.C. Nielsdóttir, P.J. Morris, H.J. Venables, A.J. Watson (2007)
The island mass effect and biological carbon uptake for the subantarctic Crozet Archipelago.
Deep-Sea Research II, 54: 2174-2190, doi:10.1016/j.dsr2.2007.06.009.
Bakker, D.C.E., A.J. Watson, and C.S. Law (2001) Southern Ocean iron enrichment promotes inorganic carbon drawdown. Deep-Sea Research II, 48: 2483-2507, doi:10.1016/S0967-0645(01)00005-4.
Bednarsek, N. (2010) Vulnerability of Southern Ocean pteropods to anthropogenic ocean acidification. PhD thesis, University of East Anglia, 284 pp.
Brown, P.J., Bakker, D.C.E., Schuster, U., Watson, A.J. (2010).
Anthropogenic carbon accumulation in the subtropical North Atlantic.
Journal of Geophysical Research 115. C04016. doi:10.1029/2008JC005043.
Boyd, P.W., A.J. Watson, C.S. Law, E.R. Abraham, T. Trull, R. Murdoch, D.C.E. Bakker,
A.R. Bowie, K.O. Buesseler, H. Chang, M.A. Charette, P. Croot, K. Downing, R.D. Frew,
M. Gall, M. Hadfield, J.A. Hall, M. Harvey, G. Jameson, J. LaRoche, M.I. Liddicoat,
R. Ling, M. Maldonado, R.M. McKay, S.D. Nodder, S. Pickmere, R. Pridmore, S. Rintoul,
K. Safi, P. Sutton, R. Strzepek, K. Tanneberger, S.M. Turner, A. Waite and J. Zeldis (2000)
A mesoscale phytoplankton bloom in the polar Southern Ocean stimulated by iron fertilization.
Nature, 407: 695-702.
Geibert, W., Assmy, P., Bakker, D.C.E., Hanfland, C., Hoppema, M., Pichevin, L., Schröder, M., Schwarz, J.N., Stimac, I., Usbeck, U., Webb, A. (2010) High productivity in an ice melting hotspot at the eastern boundary of the Weddell Gyre. Global Biogeochemical Cycles 24, GB3007, doi:10.1029/2009GB003657.
Jones, E.M. (2010) The marine carbon cycle of the Scotia Sea, Southern Ocean.
PhD thesis, University of East Anglia, UK. 307 pp.
Jones, E.M., Bakker, D.C.E., Venables, H.J.V., Whitehouse, M.J., Korb, R.E. and A.J. Watson (2010)
Rapid changes in surface water carbonate chemistry during Antartic sea ice melt. Tellus 62B, 621-635.
Schuster, U. and Watson, A.J. (2007) A variable and decreasing sink for atmospheric CO2 in the
North Atlantic. Journal of Geophysical Research 112, C11006, doi: 10.1029/2006JC003941.
Schuster, U., A. J. Watson, N. Bates, A. Corbière, M. Gonzalez-Davila, N. Metzl, D. Pierrot,
M. Santana-Casiano (2009) Trends in North Atlantic sea surface pCO2 from 1990 to 2006,
Deep-Sea Research II 56, 620-629. doi: 10.1016.j.dsr2.2008.12.011.
Telszewski, M., Chazottes, A., Schuster, U., Watson, A. J., Moulin, C.,
Bakker, D. C. E., González-Dávila, M., Johannessen, T.,
Körtzinger, A., Lüger, H., Olsen, A., Omar, A., Padin, X. A., RÃos, A., Steinhoff, T.,
Santana-Casiano, M., Wallace, D. W. R., and Wanninkhof, R. (2009)
Estimating the monthly pCO2 distribution in the North Atlantic using a
self-organizing neural network, Biogeosciences Discussions, 6, 3373-3414,
http://www.biogeosciences-discuss.net/6/3373/2009/bgd-6-3373-2009.html.
Watson, A.J., D.C.E. Bakker, P.W. Boyd, A.J. Ridgwell, and C.S. Law (2000)
Effect of iron supply on Southern Ocean CO2 uptake and implications for
glacial atmospheric CO2. Nature, 407: 730-733.
Watson, A.J., Schuster, U., Bakker, D.C.E., Bates, N., Corbiere, A., Gonzalez-Davila M.,
Friedrich, T., Hauck, J., Heinze C., Johannessen T., Kortzinger A., Metz N., Olaffson, J.,
Oschlies, A., Pfeil, B., Olsen A., Oschlies, A., Santano-Casiano, J.M., Steinhoff T., Telszewski M.,
Rios, A., Wallace, D.W.R., Wanninkhof R. (2009)
Tracking the variable North Atlantic sink for atmospheric CO2.
Science 326 (5958), 1391-1393.