Project:

  Perform CLM3-CN C4MIP Simulations and Analysis

Mission:

  Complete C4MIP Phase 1 simulations with CLM-CN model according to the
  C4MIP protocol.

Goals:

  This project depends upon the completion of a number of other projects
  which will add capabilities to CCSM3 required for performing these
  simulations.

  Perform CLM3-CN spin up runs to equilibrate carbon and nitrogen pools.

  Analyze spin up results to verify steady state of carbon and nitrogen
  pools.

  Perform CLM3-CN transient simulation for 1850-2000 period.

  Analyze model results.

  Submit model results for IPCC and C4MIP.

  Publish.

Motivation:

  Contribution from CCSM3 models to the C4MIP experiments and IPCC.

Authority:

  Inez Fung, Natalie Mahowald, Keith Lindsay, Mariana Vertenstein, and
  John Drake

Project Lead(s):

  Peter Thornton, Forrest Hoffman, and Mariana Vertenstein

Implementation Plan:

  All integrations will be performed at T31 resolution using T31_gx3v5
  datasets.

  All spin up runs will use static landuse -- the 1900 crop and pasture
  data from C4MIP protocal use to generate surface dataset

  ======================================================================
  Phase I - goal is to start this on Feb. 1 2005
  ======================================================================
  Requirements:
     ability to data cycle csim-thermo and docn
     ability to read 1900 pft dataset (even without time interpolation)
     ability to have all pfts on initial dataset (even with zero weights)
     h2ocan balance must be implemented
     desirable - ability for cam-clm to exchange co2 

  a. F run
     - 200 years CLM3-CN in C-only mode
     - CAM will write out hourly data in final 25 years
       (branch run with same case name will have to be done)
     - start from arbitrary initialization
     - cycle through 25 year SST-icefrac dataset for 200 years
       (docn and csim-thermo need to be able to data cycle)
     - co2_type = 'constant' in clm
     - undefine CPP token BGC1

  a.branch F run (C-only mode) 
     - branch from end of a. above
     - define CPP token BGC1
     - co2_type = 'prognostic' in clm
     - for this - cam can set co2 to a constant and set forc_co2_diag
       to that value (can set it to pco2 from the cam namelist)

  b. I run
     - 200 years CLM3-CN C-only mode
     - start from initial conditions at end of (I)
     - cycle through 25 years of CAM hourly data produced in (I)
     - note that docn and dice are irrelevant in this run
     - undefine CPP token BGC1

  ======================================================================
  Phase II
  ======================================================================

  a. I run
     - 1500 years CLM3-CN in CN mode (turn off supplemental N addition)
     - branch run from end of (Ib)
     - cycle through 25 years of CAM hourly data produced in (Ia)
     - note that docn and dice are irrelevant in this run

  b. F run
     - 200 years CLM3-CN in CN mode (turn off supplemental N addition)
     - CAM will write out hourly data in final 25 years
       (branch run with same case name will have to be done)
     - hybrid run
       CLM starts from initial conditions at end of (IIa)
       CAM starts from initial conditions at end of (Ia)

  ======================================================================
  Phase III
  ======================================================================

  a. I run
     - 1500 years CLM3-CN in CN mode (turn off supplemental N addition)
     - branch run from end of (IIb)
     - cycle through 25 years of CAM hourly data produced in (I)
     - note that docn and dice are irrelevant in this run

  b. F run
     - 200 years CLM3-CN in CN mode (turn off supplemental N addition)
     - CAM will write out hourly data in final 25 years
       (branch run with same case name will have to be done)
     - hybrid run
       CLM starts from initial conditions at end of (IIIa)
       CAM starts from initial conditions at end of (IIb)

  ======================================================================
  Phase IV
  ======================================================================

  F run
  - 50 years CLM3-CN in CN mode (turn off supplemental N addition)
    do two 25 years cycles of SST-icefrac
  - Spun initial conditions from (IIIb).
  - Set date to 1800

  ======================================================================
  Phase V
  ======================================================================

  F run
  - 1850-1899 prescribed ocn and anthroprogenic CO2 fluxes and static landuse
  - 1900-2000 prescribed ocn and anthroprogenic CO2 fluxes and prescribed
    landuse changes
  - branch from end of (IV)
  - cam needs CO2 merged fluxes from ocn and land (like latent heat)
  - land needs CO2 concentration data; CO2 fluxes from ocean and
    anthroprogenic emissions needs to be fed to land model
  - *CCSM system needs needs to be able to handle this*

Resources:

             I   II  III   IV    V
          ========================
    Peter    8   40   40    8   20  ~hours
  Forrest   20   80   80   10   20
  Mariana    8   20   20    2    8
           ---  ---  ---  ---  ---
    Total   36  140  140   20   48

    Total man months: 2.62

Timeline:

    I. November 1  - November 19
   II. November 22 - January 14
  III. January 17  - March 11
   IV. March 14    - March 18
    V. March 21    - April 1