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The PILPS-C1 experiment

• Results of the first phase of the project
• Complementary simulation to be done
• Proposition for the future

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Summary of the first phase of the project
Comparison of both  biophysical  and
 biogeochemical  flux from Different types of
models with observations at one EUROFLUX
site Loobos

• The site
• Temperate  mature(100 years)   coniferous
  forest
• Climate 700 mm precipitation , 9.8 C mean
  temperature
• Planted on a sand ? no soil carbon at the
  beginning of the plantation
• Measured fluxes NEE, LE,H, Rn
• Meteorological parameters incoming SW rad.,
  precipitation,
• temperature, wind speed, relative humidity,
  pressure
• -Period covered 1997-1998

Models Including SVAT with and without carbon
cycle

• Proposed simulations
• Free equilibrium simulations
• Models are run until equilibrium of state
  variables using years 1997-1998
•  in loop 
• Free 100 years run
• simulation of  realistic scenario  Beginning
  with a soil with no
• Carbon, the models are run for 1906 (plantation
  of the forest) to 1998
• Using observed climate.
• Constrained equilibrium simulations
• Same as free equilibrium but with calibrations of
  parameters
• (simulation delayed)

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The participants of the project
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PILPSC1 workshop
The workshop was held from May 6-7 2003 at CNRS
center in Gif-sur-Yvette, France. Support for
the workshop was provided by CNRS/INSU.   The
participants of the workshop where   Jean
Christophe Calvet (CNRM, France), Yeugeniy Gusev
(Institute of Water Problems, Russia), Mustapha
El Mayaar (Univ. Wisconsin,USA) Eddy Moors
(Alterra, Netherlands), Olga Nasanova (Institute
of Water Problems, Russia), Jan Polcher (LMD,
France), Vincent Rivalland (CNRM, France), Andrey
Shmakin (Institute of Geography, Russia), Diana
Verseghy (CCS, Canada), Nicolas Viovy
(LSCE,France)  
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Main results
 free equilibrium simulation 
Analysis on diurnal cycle, daily and monthly
average

• For each models
• Plots of mean diurnal cycles over 10 days
• Plots of mean seasonal diurnal cycles
• Plots of daily and monthly means
• Plots of monthly model v.s data
• Global statistics
• intercept v.s. Slope
• RMSE sys v.s. non systematic
• The RMSE systematic indicate  bias  in the
  model
• The RMSE non-systematic is the residue of the
  RMSE
• Index of agreement Global measurement of
  agreement between
• model an observation.

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Slope/intercept and RMSE unsys/sys For the
different models (3 hourly fluxes)
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Index of agreement for all models
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 100 years simulation 

• Same as for F-E run plus
• Comparison of sinks simulated and observed for
  1997 and 1998
• Trajectories of several parameters for the 93
  years of the run
• NEE
• GPP
• NPP
• Total soil carbon
• Total living biomass
• biomass increment

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Modeled and simulated carbon net sink In 1997
and 1998
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2 kind of behaviors IBIS of ORCHIDEE-1 that
reach rapidly the NPP (beginning with High
sink) CLASS or SWAP with progressive increase of
NPP (with increasing sink) MC or ORCHIDEE-2 is
between the two.
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Completion of the first phase
(end of 2003...)
New model outputs will be added
e.g LAI, separation between below and
above Biomass, height of trees.....

• Calibrated simulations with
• LAI (trees, understorey(seasonal cycle)
• Maximun unstressed assimilation
• Root zone depth
• Water table depth
• Height of trees (height of  first branches )
• Litter layer
• Soil carbon (to check if we can informations
  about partition between pools)
• Soil water content
• Soil temperature
•  

Some new analysis Separation between night/day
cloudy/clear warm/cold Estimation of WUE Ratio
NEE/total respiration.
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Main preliminary conclusion
Taking into account that models was not
calibrated The models reproduce relatively well
the observations
Sensible heat flux is overestimated at
night High net CO2 and latent heat fluxes are
underestimated
The 100 years simulation was very
interesting Since if all models give relatively
similar NEE And are all able to reproduce the
difference of Sink between 1997 and 1998,
trajectories of Models carbon fluxes and pools
are very different !
For more details on results go to http//www.pilp
sc1.cnrs-gif.fr