Modelling of Biogeochemical Cycles and Ecosystems in the Arctic Ocean

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Modelling of Biogeochemical Cycles and Ecosystems
in the Arctic Ocean

• Participants Nadja Steiner (DFO/EC), Dieter
  Wolf-Gladrow (AWI), Diane Lavoie (DFO),David
  Plummer (EC), Yvonnick Le Clainche (U. Rimouski),
  Clara Deal (IARC/UAF), Leif Anderson (U
  Gotenborg), Mat Reagan (Berkeley Lab)

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1. Science questions that can be best answered
with coupled Arctic regional climate models
science questions missing from existing plans.
Time scales current/preindustrial, future (next
decades), past (glacial-interglacial and
beyond)?
What is the impact of climate-relevant gases
produced in the ocean on Arctic climate?
How will cycling of elements (C,N,P,Ca,S,O,Fe)
change in the next decades?
Strengths of biogeochemical feedbacks.
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Cycling of nutrients and organic matter in the
current system What are the major processes?
Rates? Coherent quantitative description? How
much food is available for higher trophic
levels? (fish, mammals), Occurance of HABs...
Future changes due to temperature change,
retreat/vanishing of summer sea ice, ocean
acidification, coastal erosion, melting of
permafrost, ... What is the impact on cycling
of nutrients and organic matter? Change in marine
ecosystems (primary production, species
assemblage, ..., impact on higher trophic
levels)?
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Biogeochemical feedbacks
Sulfur DMS -gt Cloud Condensation Nuclei (CCN) -gt
-gt radiation -gt temperature -gt ...
Impact of phytoplankton blooms on mixed layer
temperature (Manizza et al., 2005)?
Impact of ice algae on melting of sea ice
(Zeebe et al., 1996)?
(Biogeo)chemistry in sea ice discovery of ikaite
(CaCO3 H2O), consequences for bromine oxid
(BrO)? formation and ozone depletion events
(ODEs) in polar marine boundary layer, mercury
sink, carbon flux within sea-ice, marine
carbonate system
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Biogeochemical feedbacks
Instability of gashydrates -gt CH4 release from
sediments -gt oxidation of CH4 in the water column
-gt ... (bacterial request of copper Scott
Elliot)?
Impact of black carbon on albedo and melting of
sea ice
Input of nutrients (including metals) and various
forms of carbon transformations in the river-sea
transition zone. Dissolution of CaCO3 in surface
sediments (ocean acidification)
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Biogeochemical feedbacks
Instability of gashydrates -gt CH4 release from
sediments -gt oxidation of CH4 in the water column
-gt ... (bacterial request of copper Scott
Elliot)?
Impact of black carbon on albedo and melting of
sea ice
Input of nutrients (including metals) and various
forms of carbon transformations in the river-sea
transition zone. Dissolution of CaCO3 in surface
sediments (ocean acidification)
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The inclusion of a biogeochemical process into
coupled models makes sense only when the
corresponding feedback implemented, e.g. when,
for example, atmospheric DMS and its
transformation is included.What do atmospheric
models represent?
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2. Existing/planned modelling and model
validation efforts to address the above
AWI Polarstern expeditions (central Arctic, Fram
Strait)
Various research activities in the Lena Delta
and Laptev Sea (river input, coastal erosion,
sedimentation)? Needed historical data review,
archive...... -gt develop modified sampling
strategies
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3. Reasonable boundaries for the 'Arctic System'
for respective research areas What are the
opportunities and limitations due to a limited
Arctic model domain?
Hydrological cycle under global change requires
larger domain (or time dependent boundary
conditions).
The same applies on somewhat longer time scale
to inflow of Atlantic and Pacific
water. Opportunities better representation of
small scale processes
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4. How are observations incorporated into model
development and how can the link be improved?
Parameterizations of various processes based
on observations.
Data assimilation/inverse models to improve
parameterizations.
Involve modellers in development of sampling
strategies (What is needed? What is
possible?)? Involve observers in model
development - improve process understanding gt
Two way communication !!! Modellers need to tell
funding agencies they need observations (seasonal
data, fill local gaps, archive historical data)?
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5. Would regional modelling efforts benefit from
an international, centralized method for sharing
model output for intercomparison and for sharing
validation data and validation code/methods?
Yes!
Open access of model output and observations
parallel to publication of articles
(collaborative ?).
Compare open access to CO2 observations (CDIAC).
Data center for validation and intercomparison
provide constraints for data submission
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6. What interactions are there between regional
modelling and global modelling in your field of
research? Would projects benefit from a
community-coordinated program for obtaining data
from and sharing model output with a global
modelling community?
Need interaction for time dependent boundary
conditions... Compexity of ecosystem models -
global versus regioal CCCma - close
collaboration between global GCM and RCM,
forecast .... for ecosystem only starting. other
groups similar? CICE, many groups collaborating,
development of parameterisations
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7. What plans are in action for including
emerging modules into existing regional arctic
models?
IARC/UAF/LANL Regional ecosystem, ice algae ,
nutrients in CICE (sea-ice internal), DMS within
ice DFO/EC Earth system model developments,
ecosystem models in ocean models, 1-D marine
sulphur cycle (DMS), ice algae Berkely Lab/
LANL coupling a gas hydrate/methane model in
POP
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8. What human dimension modelling is being done
in conjunction with physical modelling?
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9. What are possible interface strategies for
collaboration between natural-science modelling
and research on adaptation and human living
conditions?
Importance of river input ( Influx Changes with
land use changes, permafrost melting)? Ocean
acidification Fisheries Harmful algal blooms
(HABs), ...
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10.What level of interaction between components
is desirable?
Depending on feedbacks (examples Atmospheric
deposition Gas exchange with retreating ice
cover, ice ecosystem, river inflow ...)?
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11. What is the benefit of interactive coupling
on the complete system?
Inclusion of feedbacks.
Continuous simulations
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12. Which other components should your component
be coupled to?
Answer depends on questions/time scales.
Start atmosphere, ocean, ice, pelagic ecosystem
(carbonate system, nutrients, plankton)? ecosyste
m in the ice climatically active gases ...
On longer time scales add sediment module
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13. On what time scale is interactive
coupling/one-way coupling useful?
General answer depends on the feedback(s) under
investigation Limitation due to boundary
conditions in regional models.
What is required list of possible feedbacks,
their strengths and their characteristic time
constants.
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Coupling of ecosystem models with circulation
models
The coupling of ecosystem models to circulation
models is relative easy because the various
compartments of ecosystem models (nutrients, DIC,
TA, phytoplankton, zooplankton) can be treated
similar to other passive tracers, however, with
specific sources and sinks. Thus the
implementation should be possible in less
than one month. For gases (CO2, DMS, ...) air-sea
gas-exchange has to be added.
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The End
Thanks for your attention
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Discussion
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Steiner Denman 2008
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Steiner Denman 2008
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Steiner Denman 2008
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Ikaite
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Loose et al. 2009
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Type of questions
Global cycles of elements
Regional climate-relevant gases, food production
(fisheries, higher trophic levels)?
Local variations in ecosystems
Fundamental fast changes
Carmack Wassmann, 2006
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Manizza et al. 2005
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Organic Carbon Budget Arctic Ocean vs. Global
OceanStein Macdonald (2004)?
Quantity Arctic Ocean
Global Ocean Primary production
gt 330 (1) 30000 -
50000 River input (POC)
5.5
130-200 River input (DOC)
24.5 (10) 210-230 Eolian
input 1.7
100-320 Coastal
erosion 5.4
?
units all values in 106 t C year-1
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Manizza et al. 2005
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Manizza et al. 2008
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Zeebe et al. 1996
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Dieckmann et al. 2008
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Morin et al. 2008
Atmos. Chem. Phys., 8, 73177324,
2008 www.atmos-chem-phys.net/8/7317/2008/
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Zhao et al. 2008
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Earth System Model
expansion of the COSMOS
Modules (following COSMOS)?
Ice sheets model Mass balance sea
level Ice-ocean interaction Permafrost
ECHAM5
Chemistry
Isotope Proxy Models
Isotope modules 13C,18O,30Si ice cores, marine
sediments,
Ice Sheets Model
OASIS

• Biogeochemistry/Ecosystem
• marine biogeochemical cycles
• (based on RECOM)?
• continental weathering input
• sediment module

MPI-OM
HAMOCC5
Programme PACES