GEMS

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GEMS GREENHOUSE GASES
Peter Cox (Met Office)Martin Heimann, Wolfgang
Knorr (MPI-BGC)Tony Hollingsworth, Richard
Engelen (ECMWF)Philippe Ciais, Philippe Peylin
(LSCE)Alain Chedin (LMD)

• Objectives
• Heritage and Partner Projects
• Deliverables
• Workpackages

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GEMS-GHG Objectives

1. To monitor daily-to-seasonal variations in 3d
   fields of atmospheric CO2.
2. To provide improved estimates of CO2 sources and
   sinks.
3. To diagnose the relative contributions to land
   carbon sources and sinks.
4. To monitor daily-to-seasonal variations in CH4,
   N2O, CO.

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GEMS-GHG Heritage and Partner Projects

• COCO FP5 Project (Dec 2001 Dec 2004) obj. 1
• CarboEurope (FP5 cluster and FP6 IP)
• CarboEurope - AEROCARB (March 2000 March
  2003) obj. 2,3
• CarboEurope - CAMELS (Nov 2002 Nov 2005)
  obj. 3
• EVERGREEN (non-CO2 retrievals) (2002-2005)
  obj. 4
• MERSEA (includes Ocean GEMS) FP6 IP
• GEOLAND (includes Land GEMS) FP6 IP
  

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GEMS-GHG Deliverables

• Year 1 Maps of column integral CO2,120km, 10-day
  mean
• Year 2 4d fields of CO2, quality controlled
  against in situ measurements (120km,10-day mean)
• Year 2 Maps of column integral CH4, N2O, CO
  (daily?), 120km, 10-day mean
• Year 3 CO2 sources and sinks (10-day mean,
  120km) validated against bottom-up flux estimates
  (e.g. CARBOEUROPE)
• Year 4 Retrieval of process model parameters and
  attribution of CO2 sources and sinks.

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GEMS-GHG Workpackages

• 4d retrieval of CO2 from remote sensing.
  Engelen, ECMWF
• Assessment of CO2 retrievals
  Heimann, MPI-BGC
• Inversions to estimate CO2 sources and sinks
  Ciais, LSCE
• Development of a CCDAS to estimate contributions
  to land CO2 sources and sinks.
  Cox, UKMO
• Prototype system to retrieve column integral CH4,
  N2O, CO.
• 
  Chedin, LMD

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GEMS-GHG Outstanding Issues

1. Are the subproject deliverables realistic given
   the time and resource constraints? (e.g. should
   we focus just on CO2?)
2. Does the consortium have sufficient expertise in
   all of the relevant areas? Do we need additional
   groups for the forward modelling of non-CO2 GHGs?
3. How will we deal with ocean-atmosphere fluxes?
   Links to MERSEA?
4. Can we find a way to unify the two approaches to
   modelling CO2 sources and sinks?
5. How should we subdivide GEMS GHG, and who will
   lead the writing of each part? (...keep your
   heads down!)

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WP1 4d retrieval of CO2 from remote sensing ( WP
leader Richard Engelen, ECMWF)