The Design Document page provides a description of the algorithms, implementation and planned testing including unit, verification, validation and performance testing. Please read Step 1.3 Performance Expectations that explains feature documentation requirements from the performance group point of view.
Design Document
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The first table in Design Document gives overview of this document, from this info the Design Documents Overview page is automatically created. In the overview table below 4.Equ means Equations and Algorithms, 5.Ver means Verification, 6.Perf - Performance, 7. Val - Validation
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In the table below 4.Equ means Equations and Algorithms, 5.Ver means Verification, 6.Perf - Performance, 7. Val - Validation, 
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Title: Improving the efficiency of land spinup and offline model simulations
Requirements and Design
ACME Land Group
Date:
Summary
Requirements
Requirement
: name-of-requirement-here1: Provide more efficient accelerated decomposition (AD) for land biogeochemistry
Date last modified:
Contributors: Daniel Ricciuto
Each requirement is to be listed under a ”section” heading, as there will be a one-to-one correspondence between requirements, design, proposed imple- mentation and testing. Requirements should not discuss technical software issues, but rather focus on model capability. To the extent possible, require- ments should be relatively independent of each other, thus allowing a clean design solution, implementation and testing plan.
Algorithmic Formulations
Design solution: short-description-of-proposed-solution-here
Date last modified:// date
Contributors: (add your name to this list if it does not appear)
For each requirement, there is a design solution that is intended to meet that requirement. Design solutions can include detailed technical discussions of PDEs, algorithms, solvers and similar, as well as technical discussion of performance issues. In general, this section should steer away from a detailed discussion of low-level software issues such as variable declarations, interfaces and sequencing.
Design and Implementation
Implementation: short-desciption-of-implementation-here
Date last modified: // date
Contributors: (add your name to this list if it does not appear)
This section should detail the plan for implementing the design solution for requirement XXX. In general, this section is software-centric with a focus on software implementation. Pseudo code is appropriate in this section. Links to actual source code are appropriate. Project management items, such as svn branches, timelines and staffing are also appropriate. How do we typeset pseudo code?
Provide a framework to reach steady state in accelerated mode in land model (with active biogeochemistry) in a reduced amount of time (< 500 years) for any given climate, plant functional type, or choice of model parameters affecting decomposition rate.
Requirement 2: Provide option to bypass DATM and model coupler for offline land model simulations
Date last modified:
Contributors: Daniel Ricciuto
Provide a framework to read in all model relevant inputs at the time of initialization, including meteorology, nitrogen deposition, aerosol deposition, fire data, and co2 concentrations.
Requirement 3: Model code changes to enable parameter manipulation in site-level UQ studies
Date last modified:
Contributors: Daniel Ricciuto, Xiaoying Shi
Provide a python scripting framework to enable full point model simulations including spinup and transient. Extract selected current hard-coded parameters and read them from netcdf parameter files. Provide new parameterizations for storage, harvest, and photosynthetic temperature response learned from pervious site-level UQ studies (defaults will not be changed from ACME_v0).
Algorithmic Formulations
Design solution: Provide more efficient accelerated decomposition (AD) for land biogeochemistry
Date last modified:
Contributors: Daniel Ricciuto
Modification 1) if (model_year) < 20, set carbon_only mode active
Modificaiton 2) In accelerated mode For dead croot and dead stem carbon only, accelerate mortality by a factor of 10
In accelerated mode, multiply dead stem/croot carbon pools by a factor of 10 for biomass calculation in fire model.
In accelerated mode,multiply dead stem/croot carbon pools by a factor of 10 for biomass/height relationship
Modification 3) In accelerated mode, modify acceleration factors (af) of slow pools (> 1 year) from constants to a functional form: af = f(k, Q10, MAT).
MAT = mean annual temperature, k = rate constant for decomposition (at 25C), Q10 = temperature sensitivity
In accelerated mode, increase vertical transport to match acceleration factors.
Design solution: Provide option to bypass DATM and model coupler for offline land model simulations
Date last modified:
Contributors: Daniel Ricciuto
No algorithmic changes necessary.
Design solution: Model code changes to enable parameter manipulation in site-level UQ studies
Date last modified:
Contributors: Daniel Ricciuto, Xiaoying Shi
Modification of harvest subroutine to specify number of days over which to apply the harvest algorithm (default 1 year)
Modification to set minimum soil temperature for calculation of BTRAN as a parameter (default = -2 C)
Modification to include fraction of downregulation C flux sent to cpool (default is zero), introduce cpool turnover (default 1 year)
Design and Implementation
Implementation: Provide more efficient accelerated decomposition (AD) for land biogeochemistry
Date last modified:
Contributors: Daniel Ricciuto
Implementation: Provide option to bypass DATM and model coupler for offline land model simulations
Date last modified:
Contributors: Daniel Ricciuto
The following subroutines are modified (Based on v0 code; this list will be revised on further review of both CNP and interface codes)
ccsm_driver: Disable writing logfile information every timestep.
lnd_comp_mct: Disable lnd_export subroutine if cpl_bypass option is used.
atm2lndType: Define and allocate new variables for met data, co2, c13o2, ndep, aerosol, hdm, lnfm inputs (containing complete timeseries).
lnd_comp_mct: Disable export to coupler
lnd_import_export: Extensive modifications to read in met data, ndep, fire, aerosol and co2 data on time step 0.
controlMod and clm_varctl: Provide new name list options to specify directory for cpl_bypass metdata, co2_file and aerosol files (since these will be read in CLM instead of DATM)
config_compsets: Provide new compsets using SATM for cpl_bypass mode
clm_driver: Disable ndep stream file/interpolation operations. Disable writing "completed timestep" every timestep.
CNFireMod: Disable lnfm/hdm stream file/interpolation operations
Implementation: Model code changes to enable parameter manipulation in site-level UQ studies
Date last modified:
Contributors: Daniel Ricciuto
Parameters will be added to the clm_params_xxxxx.nc file and read in pft_varcon or relevant model subroutine.
Planned Verification and Unit Testing
Verification and Unit Testing:
short-desciption-of-testing-hereUQ efficiency improvements
Date last modified:
Contributors:
(add your name to this list if it does not appear)How will XXX be tested? i.e. how will be we know when we have met requirement XXX. Will these unit tests be included in the ongoing going forward?
Daniel Ricciuto, Xiaoying Shi
The planned changes to ad_spinup will not be bfb with previous tags. We will verify that the current and previous spinup methodologies produce the same steady state C pools to within 0.1 PgC globally and within 1gC/m2 for at least 95% of land grid cells in a global offline simulation. The previous ad_spinup methodology will still be available through a namelist option.
The changes to bypass the model coupler will be implemented as a new compset. We will verify that these simulations produce the same steady state as the standard IXXXXCLM45CN compset for steady state (year 1850) and transient C,N, and P pools (year 2000) to within 1% globally and for at least 95% of land grid cells in a global offline simulation.
All other changes will be verified as bfb.
Planned Validation Testing
Validation Testing:
short-desciption-of-testing-hereUQ efficiency improvements
Date last modified:
Contributors:
(add your name to this list if it does not appear)Daniel Ricciuto, Xiaoying Shi
How The ad_spinup changes will XXX be tested? What observational or other dataset will be used? i.e. how will be we know when we have met requirement XXX. Will these unit tests be included in the ongoing going forward?be tested to determine the optimal parameters (mortality acceleration, som factors, and length of time in C-only mode). requiring the least amount of spinup to reach steady state C pools.
Other model parameter and structural changes will be tested against site-level data (e.g. FLUXNET) and assessed globally using the ILAMB framework.
Planned Performance Testing
Performance Testing: short-desciption-of-testing-here
Date last modified:
How will XXX be tested? i.e. how will be we know when we have met requirement XXX. Will these unit tests be included in the ongoing going forward?
Contributors:
(add your name to this list if it does not appear)Daniel Ricciuto
Ad_spinup are not expected to impact performance in terms of CPU time per model year, but will reduce the length of required simulation. Performance will be tested using standard tools.
Cpl_bypass is expected to significantly enhance the performance of offline land model simulations. This will be tested using the standard timing tools on all major platforms.
Other parameter and structural changes are not expected to impact performance.