Changes between Version 171 and Version 172 of DevelopmentActivities/ORCHIDEE-DOFOCO


Ignore:
Timestamp:
2018-11-28T22:20:07+01:00 (5 years ago)
Author:
luyssaert
Comment:

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  • DevelopmentActivities/ORCHIDEE-DOFOCO

    v171 v172  
    383383=== Stomate === 
    384384ORCHIDEE-CN-CAN strengthen the links between sechiba and stomate. As in previous versions, stomate makes use of variables calculated in sechiba but in ORCHIDEE-CAN and ORCHIDEE-CN-CAN, sechiba requires information from stomate to work properly. For the moment set '''stomate_ok_stomate''' to y (_AUTOBLOCKER_). For the future it seems possible to prescribe LAI and assume a canopy structure but this code still needs to be restored and tested. For the time being set '''lai_map''' = n. 
     385 
     386== Parameterization and Evaluation (chronological order) == 
     387 
     388=== Workflow === 
     389The following outlines the strategy for parameterizing and evaluating the performance of ORCHIDEE-CN-CAN in simulating several key forest ecosystem processes including tree growth dynamics, energy exchange, C-N cycling and plant hydrology. 
     390 
     391The work will likely require several iteration containing all or just a coupled of the following: 1) running the model, 2) tuning key parameters, 3) re-running the model 4) spin-up and 5) evaluating to model, to discern parameter values that allow us to reproduce as closely as possible the global patterns and trends for several key processes. The tests will move across scales starting at pixel scale moving to longitudinal band, European scale and ending at global scale. Although the longitudinal bands are of little use in the evaluation itself they can be considered pre-tests before global tests are run. It is hoped that longitudinal bands would speed up the tests and reduce the computational cost. 
     392 
     393Table 0. Workflow of the parameterization and evaluation of ORCHIDEE-CN-CAN. 
     394Phase   Work to be done 
     395Prepare and check       Check whether the model runs and spin-up are apparently bug free (Table 1). Check whether the scripts, tools and data are available and still working (Table 2).  
     396Initial evaluation      Run longitudinal spin-up and check order of magnitude in soil carbon pools. Use the same runs to check response gradients to temperature, N-deposition, precipitation and management (§4.4).    
     397Parameterization        Use FLUXNET and some additional data sources to parameterize the model at the site level (Table 3). 
     398Final evaluation        Run a spin-up + transient simulation over Europe compare the simulation against the spatially explicit data (Table 4). 
     399 
     400 
     401=== Apparent bug-free === 
     402Before starting the work proposed in Table 0 it needs to be confirmed that the model is technically capable of the tasks presented in Table 1. 
     403 
     404Table 1. Essential technical capabilities before evaluating ORCHIDEE-CN-CAN. 
     405Description of the task Status 
     406Is the model stable? Can it be run for 500 - 1000 years? Can it be run for all PFTs?    Problems with grasslands 
     407Is the N-cycle working? Can we run simulations with IMPOSE_CN=n and IMPOSE_CN=y?        OK 
     408Is land cover change working? Can we run simulations with (changing) land cover maps (impose_veg=no)?   OK 
     409Is forest management working? Can we read forest management maps, are the temporal trends in biomass what is expected for unmanaged, high-stand and coppice management? Still need to run idealized set-ups 
     410Is litter raking working? Can we read litter raking maps and is the litter pool in forest decreasing and the litter pool in croplands increasing?       Still needs to be checked 
     411Does the model run in parallel?         OK 
     412Is the analytical spin-up working?      OK 
     413Do we have all the driver maps for the years 1600 to 2000 for European simulations? Climate, land cover change, forest management, litter raking, and N-deposition?     OK 
     414Do we have all the driver maps for the years 1600 to 2000 for global simulations?       Still need litter raking and FM 
     415Read N-deposition maps through COMP     ??? 
     416 
     417 
     418=== Data availability === 
     419Observational data products for model-data comparison can be found at:  /home/satellites5/maignan/ORCHIDEE/EVALUATION. 
     420•       phenology  
     421◦       GIMMS (LAI and FPAR3g) 
     422•       Forest structure 
     423◦       Remote sensing products of biomass (temperate and boreal maps, i.e., Turner) 
     424◦       Biomass of EU forest from JRC (Europe) 
     425◦       Global 1-degree Maps of Forest Area, Carbon Stocks, and Biomass, 1950-2010 (ORNL DAAC) 
     426◦       Avitabile product (Global forest biomass) 
     427◦       Forest basal area (Europe) 
     428◦       Canopy height (Global) 
     429•       NPP 
     430◦       Site-level NPP database Luyssaert et al 2007 
     431•       NEP 
     432◦       FLUXNET site-level data 
     433•       TER 
     434◦       FLUXNET site-level data 
     435•       GPP 
     436◦       FLUXNET site-level data 
     437◦       EC-based upscaled GPP, i.e., Jung 
     438•       NPP/GPP 
     439◦       site-level data and regional patterns, i.e., Campioli et al 2015 
     440•       Soil hydrology 
     441◦       ESA CCI ECV 
     442◦       measurements from Brazil (ABRACOS product) 
     443◦       River discharge records from selected gauges (Global coverage) 
     444•       Albedo 
     445◦       MODIS or GlobAlbedo for albedo 
     446•       Energy (sensible and latent heat) 
     447◦       GLEAM for evapotranspiration 
     448◦       EC-based upscaled evapotranspiration, i.e., Jung 
     449•       Tree ring width (not on /home/satellites5/) 
     450◦       ITRDB 
     451•       LCC 
     452◦       Luyssaert et al 2014 – FLUXNET changes in Rn, LE, H, G, albedo 
     453◦       Duveiller et al 2018 – Remote sensing changes in Rn, LE, H+G, albedo  
     454•       NFI 
     455◦       France, Spain, Germany and Sweden (/home/satellites5/) 
     456◦       EU-wide data through the VERIFY project? 
     457 
     458There are several data tools (ATLAS, Mapper and Jerome’s) to help compare model outputs with observation, which we might be able to use. If we will not be using the available tools for comparison, we need to preprocess the observational data products to produce global means, time series, decadal averages of spatial patterns etc. The analyses presented in Naudts et al 2015 are a good starting point for the evaluation of ORCHIDEE-CN-CAN. The following scripts are available and have been tested and re-activated 
     459 
     460Table 2. Model evaluations scripts available per November 2018 
     461Description     Status  Path 
     462Extract species-level productivity from French NFI data and compare against simulated productivity – looking to replace the French data by EU-wide data through the VERIFY project      OK      dofoco/dofoco/SCRIPTS/XXX 
     463Extract Jung GPP and compare against spatially explicit simulations for 8 regions in Europe     ???     dofoco/dofoco/ SCRIPTS/XXX 
     464Extract Jung evapotranspiration and compare against spatially explicit simulations for 8 regions in Europe      ???     dofoco/dofoco/ SCRIPTS/XXX 
     465Extract MODIS albedo (NIR & VIS) and compare against spatially explicit simulations for 8 regions in Europe     ???     dofoco/dofoco/ SCRIPTS/XXX 
     466Extract height and compare against spatially explicit simulations for 8 regions in Europe       ???     dofoco/dofoco/ SCRIPTS/XXX 
     467Extract effective LAI and compare against spatially explicit simulations for 8 regions in Europe        ???     dofoco/dofoco/ SCRIPTS/XXX 
     468Extract BA and compare against spatially explicit simulations for 8 regions in Europe   ???     dofoco/dofoco/ SCRIPTS/XXX 
     469Extract half-hourly EC observations and compare with half-hourly site level simulations for NEP, GPP, TER, and evapotranspiration       ???     ENSEMBLE/FLUXNET 
     470Extract half-hourly EC observations and compare with half-hourly site level simulations for albedo      ???     ENSEMBLE/FLUXNET 
     471 
     472 
     473=== Parameterization === 
     474As we will compare the simulations to observations, the simulations need to be our best shot to resemble reality. Hence, all site-level simulations made for the parameterization will have the following configuration: 
     475•       start from a spin-up 
     476•       impose_cn = no (i.e., accounting for N-deposition ) 
     477•       Forest management = 2 (i.e., accounting for a thin and fell type of forest management) 
     478 
     479European simulations will have the following configuration: 
     480•       start from a spin-up 
     481•       impose_cn = no (i.e., accounting for N-deposition ) 
     482•       impose_veg = no (i.e., accounting for PFT distribution) 
     483•       Forest management from map 
     484 
     485The following parameterization approach – making use of parameters that were already shown to be sensitive to tuning – is proposed: 
     486 
     487Table 3. Proposed order, parameters and tools to parameterize ORCHIDEE-CN-CAN. Once all steps has been performed, the NPP to GPP ratio should be re-evaluated, possibly resulting in another tuning cycle for some of the PFTs. 
     488Process Parameter(s)    Tool 
     489Onset of growing season and start of senescence thresholds for phenology        FLUXNET 
     490NPP/GPP ratio   coeff for maintenance respiration       FLUXNET + Campioli 
     491Magnitude of LAI        k_latosa_min and k_latosa_max   NFI + Luyssaert et al 2007 
     492Magnitude of GPP        LL_alpha, Vcmax, J_max  FLUXNET 
     493Magnitude of NPP        Implicit through NPP/GPP and GPP        Luyssaert et al 2007 
     494Evapotranspiration      LAI_top, water stress   FLUXNET 
     495Water stress    To be discovered        FLUXNET 
     496Magnitude of Rh To be checked - Rh      Luyssaert et al 2007 
     497Magnitude of TER        To be checked - Rh      FLUXNET 
     498Diameter, height, and biomass   form factor     NFI + Luyssaert et al 2007 
     499density and biomass     self-thinning parameters        NFI + Luyssaert et al 2007 
     500Harvest and biomass     Self-thinning and RDI parameters        NFI + ??? 
     501Albedo  Implicit through LAI and forest structure       FLUXNET? 
     502Tree ring width Self-thinning, recruitment      ITRDB or VERIFY Fig 4 
     503 
     504 
     505==== Settings for the FLUXNET comparison ==== 
     506The parameterization starts with several 1-pixel test cases coinciding with long-term flux-net sites to test whether the model captures the growth dynamics such as phenology, max LAI, GPP, etc. These tests require a spin-up. The 1-pixel test cases will allow for both parameter tuning and changes in the code to improve the model behavior. The majority of the data represent mature forests, hence, the modelled forests should be mature as well. The model will be run for 80 years, before any output will be compared to the FLUXNET measurements. An iterative process is be planned: 
     507 
     508•       80 years to reach mature forest → parameterize 
     509•       Re-run the 80 years to reach mature forest with the new parameters → parameterize 
     510•       Re-run spin-up and 80 year simulation to reach mature forest with the new parameters → parameterize  
     511•       Continue until satisfied 
     512 
     513Only if we experience too many difficulties with manual tuning (if there are too many non-linearities in the model), we will use the multi-site optimization tool developed by Vlad . When the simulated growth dynamics are satisfying, 140 years long tests will be performed to check cumulative variables such as basal area, tree height, tree diameter, stand density, standing biomass, and harvest. To evaluate net ecosystem exchange of carbon and soil carbon and nitrogen pools a spin-up is required. Note that the spin-up depends on the parameters used in ORCHIDEE and that the sensitivity of parameters in ORCHIDEE depends on the spin-up. There is no easy way to break this dependency. We should avoid to ‘over-tune’ the 1-pixel FLUXNET comparisons. Instead, we will continue evaluating the model over longitudinal bands.  
     514 
     515 
     516==== Settings for longitudinal bands ==== 
     517Test with longitudinal bands will be used to ensure that we have the expected gradients across regions (response to: climate, precipitation, management, and nitrogen). Longitudinal bands will not be (formally) compared against data, they should be considered as intermediate tests. If the expected responses are not present in the longitudinal bands, there is no reason to expect that they will be present in the European/global runs. Therefore, the issue should be investigated/fixed before launching large scale simulations. 
     518   
     519Three longitudinal tests will be conducted covering 2 pixels wide bands from N-Canada to Southern Chili, N-Norway to S-Africa and one band N-E Russia to Australia (including W-Australia → only place where something grows in Australia). If the evaluation is limited to checking whether response gradients are indeed present in the simulations, the configuration could be limited to running the analytical spin-up until equilibrium. Once we moved on to the longitudinal bands the focus will be on tuning of parameters. Any problems with the model and its functionality should have been caught during the 1-pixel and longitudinal tests. 
     520 
     521Longitudinal bands can be run largely independent from the 1-pixel tests. After concluding the 1-pixels tests it probably makes sense to run the longitudinal bands to check whether the latest parameters still produce the expected response gradients. 
     522 
     523         
     524==== Settings for European tests ==== 
     525Once happy with the pixel and longitudinal tests we will move on to the European scale. Ultimately, the aim is to produce the control run for future simulation experiments. The model should be spin-up for 1600 by making use of the 1901-1920 climatology (because those are the coldest decades in the climate forcing). During the spin-up the forest management map and N-deposition maps for 1600 should be used. As a consequence, equilibrium soil carbon should be tested at the regional scale rather than the individual pixels.  
     526 
     527Subsequently, a transient spin-up will be run starting from the 1600 spin-up. During this spin-up, changes in forest management, CO2, N-deposition, litter-raking, and land cover change will be accounted for. The climate data will still have to cycle over 1901-1920. The transient simulation will run until 1750 and, pending on successful evaluation, extended until 1950 and 2015. 1750, 1950 and 2015 are common starting points for simulation experiments.  
     528 
     529Whether we take 20 or 30 years climate-cycles depends on the exact length of the simulation; the target is that by the time the simulation reaches the year 1901, a cycle has been completed and so the cycle in the climate forcing is synchronized with the simulation years. 
     530 
     531The European control should be run from the year 1601 to 2015 includes: 
     532 
     533•       A spin-up as initial condition to make a European 1° x 1° CONTROL simulation 
     534•       64 PFTs (some with 4 age classes) 
     535•       With forest management 
     536•       Litter raking 
     537•       Increasing atmospheric CO2 concentrations read from file 
     538•       LCC 
     539•       CRU-NCEP meteorological forcing, cyclic meteorology (1901-1920) until 1900, then use the corresponding year 
     540•       A dynamic N-cycle (impose_cn=n) 
     541•       N-deposition, we have N-deposition files from approximately 1860 until present. 
     542 
     543Table 4. Observational data products to evaluate European control simulation 
     544Observations    Tool 
     545EU-wide NFI data (Fig. 3) through the VERIFY project    ??? 
     546Jung GPP – relies on FLUXNET thus partly circular       XXX 
     547Jung evapotranspiration – relies on FLUXNET thus partly circular        XXX 
     548MODIS albedo NIR & VIS  XXX 
     549Remote sensing tree height      XXX 
     550Extract effective LAI from MODIS        XXX 
     551BA from JRC – relies on NFI thus partly circular        XXX 
     552Biomass from JRC – relies on NFI thus partly circular   ??? 
     553Biomass from Turner – Remote sensing?   ??? 
     554Harvest from Schelhaas - data through the VERIFY project        ??? 
     555LCC – Luyssaert et al 2014      XXX 
     556LCC – Duveiller et al 2018      ??? 
     557 
     558 
     559==== Settings for spin-up and re-parameterization ==== 
     560As a spin-up is costly in both time and computer resources, we need a strategy to avoid wasting these resources. Thus, the spin-up will like the parameterization, be done across scale moving from pixel to global scale. The spin-up will be done in parallel with the parameterization. Often the problems with the spin-up have a technical characters and show up for the pixels with extreme climate conditions. Before launching a longitudinal, regional or global spin-up, we should agree on the model version to use, because structural changes to the code will necessitate re-running the spin-up. The model version to use, will most likely be the version ready once the parameterization at the 1-pixel level is satisfying, and no more changes to the code need be added.  
     561 
     562•       Identify the variables that are targeted by the spin-up (such as NEP, heterotrophic respiration, decomposition etc). The spin-up will reveal whether parameters affecting these variables need to be tuned. The spin-up itself is also an interesting test case that could be loosely compared against data. 
     563•       We could compare the spin-ups to maps of soil carbon stocks to check the order of magnitude. Soil carbon maps should only be formally compared with the control run (spin-up + transient simulation) for the year 2000 because that run includes the simulated effects of N-deposition, management, litter raking and land cover change. The more simple configurations of the spin-up do not account for these processes or do not account for the right sequence of processes