Attendees

Philippe Peylin, Vlad, Bastrikov,  Marie Perillou, Christoph Rüdiger Souhail Boussetta Gianpaolo Balsamo Joe McNorton Anna Agusti-Panareda

Presentation

CAMS2_52a_WP3-Sep26.pptx

Philippe Peylin presented the strategy for the C pool implementation in ecLand based on the old ORCHIDEE allocation scheme (before the allometric rules to represent tree height were implemented)

Discussion

• Gianpaolo: Complexity of carbon pools: introduce pools under logical flags. Needs to pass all the CI tests, like for SPARKY (in CY50R1 open IFS?). 
• Joey: SPARKY has already 4 pools relevant to the fire fuel which have grib codes. Dead leaves, live leaves, dead wood, live wood  
• Chris: Vertically discretised soil pools.
• If the carbon pools are not in equilibrium, there will be a drift in NEE, which will produce artificial trends.
• Gianpaolo: When implementing the water table also found the model wants to go to its own equilibrium. The slow carbon pools will be set to be in equilibrium. Other datasets (e.g. SWHD) can be treated as benchmark. 
• Philippe, Gianpaolo: The equilibrium can be achieved using an analytical approach given the model is simple: the LAI and ABG biomass can be contained with observations and the other pools can be adjusted to close the budget. 
• Philippe: How to deal with LAI increments from satellites and the closure of the carbon budget. Anna: Closing the carbon budget is important. 
• Joey: SPARKY start with LAI increment then convert to SLA (specific leaf area) and distribute the increment across fuel  pools 
• Chris: Mentioned disadvantages of LAI increments that could also be wrong. There is the option for NWP to also use dynamic LAI (Souhail's work). Observed LAI is not defined in the same way as the LAI in the model. 
• LSCE will do the first implementation of the C pools at the LSCE computing system, but CY501 should be used.
  • 1st step will be to identify all the ORCHIDEE modules/routines required for the C pools
  • 2nd step: link to ecLand variables
  • 3rd step: do a first test at LSCE
  • 4th step: transfer to ECMWF HPC as soon as possible
• Gianpaolo: Recommend to use PLUMBER sites used in CalMIP (~42 sites)
• The CalMIP sites will be used to evaluate model at FLUXNET sites
• The changes in the C pools should also consider the coupling with the CH4 wetland model, even if a full operational implementation might not be possible. 

Next meeting: 5 October at 1pm (UK time)