Carbon Fusion/NCEO meeting on Carbon Cycle Data Assimilation

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Carbon Fusion/NCEO meeting on Carbon Cycle Data
Assimilation

• Mathew Williams
• University of Edinburgh

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Overall aims

• to review, define and refine principles and
  approaches to carbon cycle DA in the UK
• to place UK work in its international context
• to identify how UK activities can support each
  other, with particular emphasis on specifying
  future activities in the NCEO

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Uncertainties in the Carbon Cycle

• Atmospheric C inventory and anthropogenic
  emissions and ocean C are well known
• Detailed inventories and fluxes at some sites
• Large uncertainties in
• carbon-climate coupling
• regional carbon stocks dynamics
• Lack of regional data is a major short-coming for
  model development testing

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Constraints on Global C Budget Data Strength of Constraint (uncertainty)
Atmospheric C inventory and its rate of change Atmospheric concentration record Strong (lt5)
C emissions from fossil fuels and cement manufacture Carbon Dioxide Information Analysis Centre (CDIAC) Strong (lt5)
Anthropogenic C in the oceans Ocean surveys (GEOSECS, WOCE, ongoing repeat sections) Strong (lt5)
Patterns in atmospheric CO2 and inverse modeling of atmospheric transport Atmospheric CO2 records (NOAA/ESRL and other networks) Intermediate (50)
Air-sea partial pressure differences Atmospheric CO2 and ocean surface pCO2 Intermediate for magnitudes (50) Good for spatio-temporal patterns
Fire emissions Forest and peat records, atmospheric records, Global Fire Emission Database Intermediate (50)
Deforestation (mainly tropics) Remote sensing and atmospheric records (CO2) Weak (100 )
Forest changes Forest censuses Strong in N America, Amazon, Europe. Elsewhere weak or missing.
Soils Inventories Weak
Peat Inventories Weak
Source M Gloor
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Observational weaknesses

• Atmospheric CO2 network
• Sparse w/ large tropical/equatorial gaps
• Fire records
• Quantifying carbon emissions
• Land use change and deforestation
• Within the tropics
• Magnitude of air-sea fluxes of CO2
• High resolution fossil CO2 emissions

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Outstanding science questions

• What is the relative importance of the
  land-biosphere CO2 fluxes over different
  latitudes?
• Which processes control land-biosphere fluxes?
• How much carbon is emitted from biomass burning,
  deforestation and land use change?
• What is the magnitude and distribution of air-sea
  exchange of CO2?
• How much will large stores of C in high latitudes
  contribute to future C emissions?

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Resolving the questions

• High resolution atmospheric CO2 data from
  OCO/GOSAT
• New fire products (burned area, energy)
• Tall tower network
• Flux tower network
• Optical EO for phenology
• Radar EO for plant biomass
• Remote sensing of soil moisture, wetland extent,
  permafrost

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Ecological (mis)understanding

• Respiration allocation
• C-water-climate interactions physiological,
  structural, successional
• C-fire interactions litter/fuel, population
  impacts
• C-nutrient interactions N deposition, warming
• Methane emissions

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Workflow for modelling and interpretation of
local data
C fluxes
Local C fluxes, dynamics parameters
Reflectance/ Backscatter
C stocks
Science questions
Error Characterisation
Flux analysis
Assimilation
Model Intercomparison
Observation Operators)
Parameter error characterisation
C Models
Initial Conditions
Drivers
Parameters
Science questions