From 152f5d6d814272bd1aee2a76e0069093999de6ef Mon Sep 17 00:00:00 2001 From: Samuel Levis Date: Tue, 29 Oct 2024 18:29:17 -0600 Subject: [PATCH 1/5] Remove/replace refs to DATM_C*_YR_* variables --- ...tmospheric-forcing-to-spinup-the-model.rst | 4 +-- .../customizing-the-clm-configuration.rst | 34 ++++++------------- src/main/clm_varctl.F90 | 2 +- tools/contrib/run_clm_historical | 12 +++---- tools/contrib/run_clmtowers | 14 ++++---- 5 files changed, 27 insertions(+), 39 deletions(-) diff --git a/doc/source/users_guide/running-special-cases/Running-with-MOAR-data-as-atmospheric-forcing-to-spinup-the-model.rst b/doc/source/users_guide/running-special-cases/Running-with-MOAR-data-as-atmospheric-forcing-to-spinup-the-model.rst index 769755937d..a81465c699 100644 --- a/doc/source/users_guide/running-special-cases/Running-with-MOAR-data-as-atmospheric-forcing-to-spinup-the-model.rst +++ b/doc/source/users_guide/running-special-cases/Running-with-MOAR-data-as-atmospheric-forcing-to-spinup-the-model.rst @@ -10,7 +10,7 @@ Because it takes so long to spinup the CN model (as we just saw previously), if In this example we will use the ``I1850Clm50BgcSpinup compset`` to setup CLM to run with atmospheric forcing from a previous fully coupled simulation with data that is already stored on disk on Cheyenne. There are several simulations that have high frequency data for which we can do this. You can also do this on a machine other than Cheyenne, but would need to download the data from the Earth System Grid and change the datapath similar to Example :numref:`eg-sim-data-from-prev-sim`. -Example: Simulation with MOAR Data on cheyenne +Example: Simulation with MOAR Data on derecho ------------------------------------------------------------- :: @@ -21,7 +21,7 @@ Example: Simulation with MOAR Data on cheyenne > ./xmlchange DATM_CPL_CASE=b40.1850.track1.1deg.006a # The following sets the align year and years to run over for atm forcing # (you could also use an editor) - > ./xmlchange DATM_CPL_YR_ALIGN=1,DATM_CPL_YR_START=960,DATM_CPL_YR_END=1030 + > ./xmlchange DATM_YR_ALIGN=1,DATM_YR_START=960,DATM_YR_END=1030 > ./case.setup # Now build and run as normal > ./case.build diff --git a/doc/source/users_guide/setting-up-and-running-a-case/customizing-the-clm-configuration.rst b/doc/source/users_guide/setting-up-and-running-a-case/customizing-the-clm-configuration.rst index 7cd8ce9c9c..11e996ae5d 100644 --- a/doc/source/users_guide/setting-up-and-running-a-case/customizing-the-clm-configuration.rst +++ b/doc/source/users_guide/setting-up-and-running-a-case/customizing-the-clm-configuration.rst @@ -510,13 +510,10 @@ For running "I" cases there are several other noteworthy configuration items tha CCSM_BGC DATM_MODE DATM_PRESAERO - DATM_CLMNCEP_YR_ALIGN - DATM_CLMNCEP_YR_START - DATM_CLMNCEP_YR_END + DATM_YR_ALIGN + DATM_YR_START + DATM_YR_END DATM_CPL_CASE - DATM_CPL_YR_ALIGN - DATM_CPL_YR_START - DATM_CPL_YR_END ``CCSM_CO2_PPMV`` Sets the mixing ratio of CO2 in parts per million by volume for ALL CESM components to use. Note that most compsets already set this value to something reasonable. Also note that some compsets may tell the atmosphere model to override this value with either historic or ramped values. If the ``CCSM_BGC`` variable is set to something other than "none" the atmosphere model will determine CO2, and CLM will listen and use what the atmosphere sends it. On the CLM side the namelist item ``co2_type`` tells CLM to use the value sent from the atmosphere rather than a value set on it's own namelist. @@ -569,36 +566,27 @@ For running "I" cases there are several other noteworthy configuration items tha ``pt1_pt1`` = read in single-point or regional datasets -DATM_CLMNCEP_YR_START - ``DATM_CLMNCEP_YR_START`` sets the beginning year to cycle the atmospheric data over for ``CLM_QIAN`` or ``CLMCRUNCEP`` modes. +DATM_YR_START + ``DATM_YR_START`` sets the beginning year to cycle the atmospheric data over for ``CLM_QIAN`` or ``CLMCRUNCEP`` or ``CPLHISTForcing`` modes. -DATM_CLMNCEP_YR_END - ``DATM_CLMNCEP_YR_END`` sets the ending year to cycle the atmospheric data over for ``CLM_QIAN`` or ``CLMCRUNCEP`` modes. +DATM_YR_END + ``DATM_YR_END`` sets the ending year to cycle the atmospheric data over for ``CLM_QIAN`` or ``CLMCRUNCEP`` or ``CPLHISTForcing`` modes. -DATM_CLMNCEP_YR_ALIGN - ``DATM_CLMNCEP_YR_START`` and ``DATM_CLMNCEP_YR_END`` determine the range of years to cycle the atmospheric data over, and ``DATM_CLMNCEP_YR_ALIGN`` determines which year in that range of years the simulation will start with. +DATM_YR_ALIGN + ``DATM_YR_START`` and ``DATM_YR_END`` determine the range of years to cycle the atmospheric data over, and ``DATM_YR_ALIGN`` determines which year in that range of years the simulation will start with. DATM_CPL_CASE ``DATM_CPL_CASE`` sets the casename to use for the ``CPLHISTForcing`` mode. -DATM_CPL_YR_START - ``DATM_CPL_YR_START`` sets the beginning year to cycle the atmospheric data over for the ``CPLHISTForcing`` mode. - -DATM_CPL_YR_END - ``DATM_CPL_YR_END`` sets the ending year to cycle the atmospheric data over for the ``CPLHISTForcing`` mode. - -DATM_CPL_YR_ALIGN - ``DATM_CPL_YR_START`` and ``DATM_CPL_YR_END`` determine the range of years to cycle the atmospheric data over, and ``DATM_CPL_YR_ALIGN`` determines which year in that range of years the simulation will start with. - ----------------------------- Downloading DATM Forcing Data ----------------------------- In Chapter One of the `CESM User's Guide `_ there is a section on "Downloading input data". The normal process of setting up cases will use the "scripts/ccsm_utils/Tools/check_input_data" script to retrieve data from the CESM subversion inputdata repository. This is true for the standard `CLM_QIAN` forcing as well. -The `CLMCRUNCEP` data is uploaded into the subversion inputdata repository as well -- but as it is 1.1 Terabytes of data downloading it is problematic (*IT WILL TAKE SEVERAL DAYS TO DOWNLOAD THE ENTIRE DATASET USING SUBVERSION*). Because of its size you may also need to download it onto a separate disk space. We have done that on cheyenne for example where it resides in ``$ENV{CESMROOT}/lmwg`` while the rest of the input data resides in ``$ENV{CESMDATAROOT}/inputdata``. The data is also already available on: janus, franklin, and hopper. If you download the data, we recommend that you break your download into several chunks, by setting up a case and setting the year range for ``DATM_CPL_YR_START`` and ``DATM_CPL_YR_END`` in say 20 year sections over 1901 to 2010, and then use ``check_input_data`` to export the data. +The `CLMCRUNCEP` data is uploaded into the subversion inputdata repository as well -- but as it is 1.1 Terabytes of data downloading it is problematic (*IT WILL TAKE SEVERAL DAYS TO DOWNLOAD THE ENTIRE DATASET USING SUBVERSION*). Because of its size you may also need to download it onto a separate disk space. We have done that on derecho for example where it resides in ``$ENV{CESMROOT}/lmwg`` while the rest of the input data resides in ``$ENV{CESMDATAROOT}/inputdata``. The data is also already available on: janus, franklin, and hopper. If you download the data, we recommend that you break your download into several chunks, by setting up a case and setting the year range for ``DATM_YR_START`` and ``DATM_YR_END`` in say 20 year sections over 1901 to 2010, and then use ``check_input_data`` to export the data. -The ``CPLHISTForcing`` DATM forcing data is unique -- because it is large compared to the rest of the input data, and we only have a disk copy on cheyenne. The DATM assumes the path for the previous NCAR machine cheyenne of ``/glade/p/cesm/shared_outputdata/cases/ccsm4/$DATM_CPLHIST_CASE`` for the data. So you will need to change this path in order to run on any other machine. You can download the data itself from NCAR HPSS from ``/CCSM/csm/$DATM_CPLHIST_CASE``. +The ``CPLHISTForcing`` DATM forcing data is unique -- because it is large compared to the rest of the input data, and we only have a disk copy on derecho. The DATM assumes the path for derecho of ``/glade/p/cesm/shared_outputdata/cases/ccsm4/$DATM_CPLHIST_CASE`` for the data. So you will need to change this path in order to run on any other machine. You can download the data itself from NCAR HPSS from ``/CCSM/csm/$DATM_CPLHIST_CASE``. -------------------------------------- Customizing via the build script files diff --git a/src/main/clm_varctl.F90 b/src/main/clm_varctl.F90 index 5fa2602e5a..9539060200 100644 --- a/src/main/clm_varctl.F90 +++ b/src/main/clm_varctl.F90 @@ -289,7 +289,7 @@ module clm_varctl logical, public :: spinup_matrixcn = .false. !.false. ! true => use acc spinup logical, public :: hist_wrt_matrixcn_diag = .false.!.false. ! true => use acc spinup ! SASU - integer, public :: nyr_forcing = 10 ! length of forcing years for the spin up. eg. if DATM_CLMNCEP_YR_START=1901;DATM_CLMNCEP_YR_END=1920, then nyr_forcing = 20 + integer, public :: nyr_forcing = 10 ! length of forcing years for the spin up. eg. if DATM_YR_START=1901;DATM_YR_END=1920, then nyr_forcing = 20 integer, public :: nyr_SASU = 1 ! length of each semi-analytic solution. eg. nyr_SASU=5, analytic solutions will be calculated every five years. ! nyr_SASU=1: the fastest SASU, but inaccurate; nyr_SASU=nyr_forcing(eg. 20): the lowest SASU but accurate integer, public :: iloop_avg = -999 ! The restart file will be based on the average of all analytic solutions within the iloop_avg^th loop. diff --git a/tools/contrib/run_clm_historical b/tools/contrib/run_clm_historical index cd293d5867..8dc9269d3b 100755 --- a/tools/contrib/run_clm_historical +++ b/tools/contrib/run_clm_historical @@ -76,9 +76,9 @@ cp original_user_nl_clm user_nl_clm ./xmlchange STOP_N=21 ./xmlchange CONTINUE_RUN=FALSE ./xmlchange RESUBMIT=0 -./xmlchange DATM_CLMNCEP_YR_ALIGN=1901 -./xmlchange DATM_CLMNCEP_YR_START=1901 -./xmlchange DATM_CLMNCEP_YR_END=1920 +./xmlchange DATM_YR_ALIGN=1901 +./xmlchange DATM_YR_START=1901 +./xmlchange DATM_YR_END=1920 # need to use user_nl_datm files to get years right cp user_nl_datm1901-1920 user_nl_datm @@ -203,9 +203,9 @@ gzip $DDIR$CASENAME*.bin # we have to resubmit the job 3 times. ./xmlchange STOP_OPTION=nyears ./xmlchange STOP_N=22 -./xmlchange DATM_CLMNCEP_YR_ALIGN=1901 -./xmlchange DATM_CLMNCEP_YR_START=1901 -./xmlchange DATM_CLMNCEP_YR_END=2014 +./xmlchange DATM_YR_ALIGN=1901 +./xmlchange DATM_YR_START=1901 +./xmlchange DATM_YR_END=2014 ./xmlchange CONTINUE_RUN=TRUE ./xmlchange RESUBMIT=3 diff --git a/tools/contrib/run_clmtowers b/tools/contrib/run_clmtowers index e4dd2519ff..7e9dbbc426 100755 --- a/tools/contrib/run_clmtowers +++ b/tools/contrib/run_clmtowers @@ -211,9 +211,9 @@ foreach mysite ( $sites ) ./xmlchange --id STOP_OPTION --val nyears ./xmlchange --id STOP_N --val $numyears ./xmlchange --id RUN_STARTDATE --val $startyear[$cnt]-01-01 - ./xmlchange --id DATM_CLMNCEP_YR_ALIGN --val $startyear[$cnt] - ./xmlchange --id DATM_CLMNCEP_YR_START --val $startyear[$cnt] - ./xmlchange --id DATM_CLMNCEP_YR_END --val $endyear[$cnt] + ./xmlchange --id DATM_YR_ALIGN --val $startyear[$cnt] + ./xmlchange --id DATM_YR_START --val $startyear[$cnt] + ./xmlchange --id DATM_YR_END --val $endyear[$cnt] ./xmlchange --id CALENDAR --val GREGORIAN if ($BGC == ON) then ./xmlchange --id CLM_BLDNML_OPTS --val "-mask navy -bgc bgc -crop" @@ -240,9 +240,9 @@ foreach mysite ( $sites ) else ./xmlchange --id RUN_STARTDATE --val $startyear[$cnt]-01-01 endif - ./xmlchange --id DATM_CLMNCEP_YR_ALIGN --val $alignyear - ./xmlchange --id DATM_CLMNCEP_YR_START --val $startyears - ./xmlchange --id DATM_CLMNCEP_YR_END --val $endyears + ./xmlchange --id DATM_YR_ALIGN --val $alignyear + ./xmlchange --id DATM_YR_START --val $startyears + ./xmlchange --id DATM_YR_END --val $endyears if ($alignyear == 1) then ./xmlchange --id CALENDAR --val NO_LEAP endif @@ -263,7 +263,7 @@ foreach mysite ( $sites ) ./preview_namelists # Have to force this for some reason if ($SPINUP_P1 == FALSE) then - ./xmlchange --id DATM_CLMNCEP_YR_END --val $endyear[$cnt] + ./xmlchange --id DATM_YR_END --val $endyear[$cnt] ./preview_namelists endif if ( $status != 0 )then From f2a8ce051099244efd3cbd38279865ea04f1d61f Mon Sep 17 00:00:00 2001 From: Samuel Levis Date: Tue, 29 Oct 2024 18:46:45 -0600 Subject: [PATCH 2/5] Remove some more DATM_C..._YR_... --- cime_config/buildnml | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-) diff --git a/cime_config/buildnml b/cime_config/buildnml index e9b7a610cd..e06b9388c7 100644 --- a/cime_config/buildnml +++ b/cime_config/buildnml @@ -52,16 +52,8 @@ def buildnml(case, caseroot, compname): clm_accelerated_spinup = case.get_value("CLM_ACCELERATED_SPINUP") comp_interface = case.get_value("COMP_INTERFACE") lilac_mode = case.get_value("LILAC_MODE") - if comp_interface == "nuopc": - yr_start = case.get_value("DATM_YR_START") - yr_end = case.get_value("DATM_YR_END") - else: - yr_start = case.get_value("DATM_CLMNCEP_YR_START") - yr_end = case.get_value("DATM_CLMNCEP_YR_END") - - if yr_start != None and yr_start < 0: - yr_start = case.get_value("DATM_CPLHIST_YR_START") - yr_end = case.get_value("DATM_CPLHIST_YR_END") + yr_start = case.get_value("DATM_YR_START") + yr_end = case.get_value("DATM_YR_END") # For LILAC if yr_start == None or lilac_mode == "on": From c697c76a5bec4837075f82eacef45ef36b7eeab0 Mon Sep 17 00:00:00 2001 From: Samuel Levis Date: Tue, 29 Oct 2024 18:51:47 -0600 Subject: [PATCH 3/5] Remove additional DATM_C..._YR_... --- .../running-special-cases/Running-with-anomaly-forcing.rst | 2 +- ...us-simulation-as-atmospheric-forcing-to-spinup-the-model.rst | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/doc/source/users_guide/running-special-cases/Running-with-anomaly-forcing.rst b/doc/source/users_guide/running-special-cases/Running-with-anomaly-forcing.rst index 0c6009f3fe..2efa65893d 100644 --- a/doc/source/users_guide/running-special-cases/Running-with-anomaly-forcing.rst +++ b/doc/source/users_guide/running-special-cases/Running-with-anomaly-forcing.rst @@ -42,4 +42,4 @@ For single point simulations, the global anomaly forcing files can be used, but mapalgo = 'nn','nn','nn','nn','nn','nn','nn','nn','nn','nn','nn','nn','nn' (the number of 'nn' values will depend on the number of original streams plus the number of anomaly forcing streams) -The cycling of the present-day (base) climate is controlled through the DATM\_CLMNCEP\_YR\_START and DATM_CLMNCEP\_YR\_END variables in env\_run.xml. +The cycling of the present-day (base) climate is controlled through the DATM\_YR\_START and DATM\_YR\_END variables in env\_run.xml. diff --git a/doc/source/users_guide/running-special-cases/Running-with-your-own-previous-simulation-as-atmospheric-forcing-to-spinup-the-model.rst b/doc/source/users_guide/running-special-cases/Running-with-your-own-previous-simulation-as-atmospheric-forcing-to-spinup-the-model.rst index 2a55cbed1e..88d209c0d1 100644 --- a/doc/source/users_guide/running-special-cases/Running-with-your-own-previous-simulation-as-atmospheric-forcing-to-spinup-the-model.rst +++ b/doc/source/users_guide/running-special-cases/Running-with-your-own-previous-simulation-as-atmospheric-forcing-to-spinup-the-model.rst @@ -51,7 +51,7 @@ Example: Simulation Forced with Data from the Previous Simulation > ./xmlchange DATM_CPLHIST_CASE="myB1850" # The following sets the align year and years to run over for atm forcing # (you could also use an editor) - > ./xmlchange DATM_CPLHIST_YR_ALIGN="1",DATM_CPLHIST_YR_START=1,DATM_CPLHIST_YR_END=20 + > ./xmlchange DATM_YR_ALIGN="1",DATM_YR_START=1,DATM_YR_END=20 # Set the strm_datdir in the namelist_defaults_datm.xml # file to the archival path of the case above in the form of: /glade/home/achive/$USER/$DATM_CPLHIST_CASE/cpl/hist # NOTE: THIS WILL CHANGE THE PATH FOR ALL I1850Clm50BgcSpinup COMPSET CASES MADE AFTER THIS! From 862739bcbd044133e12afb9a60c0562d67bece44 Mon Sep 17 00:00:00 2001 From: Samuel Levis Date: Wed, 30 Oct 2024 10:47:32 -0600 Subject: [PATCH 4/5] Replace outdated DATM_CPL_CASE with DATM_CPLHIST_CASE --- ...AR-data-as-atmospheric-forcing-to-spinup-the-model.rst | 2 +- .../customizing-the-clm-configuration.rst | 8 ++++---- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/doc/source/users_guide/running-special-cases/Running-with-MOAR-data-as-atmospheric-forcing-to-spinup-the-model.rst b/doc/source/users_guide/running-special-cases/Running-with-MOAR-data-as-atmospheric-forcing-to-spinup-the-model.rst index a81465c699..cf9fbc773c 100644 --- a/doc/source/users_guide/running-special-cases/Running-with-MOAR-data-as-atmospheric-forcing-to-spinup-the-model.rst +++ b/doc/source/users_guide/running-special-cases/Running-with-MOAR-data-as-atmospheric-forcing-to-spinup-the-model.rst @@ -18,7 +18,7 @@ Example: Simulation with MOAR Data on derecho > ./create_newcase -case MOARforce1850 -res f19_g17_gl4 -compset I1850Clm50BgcSpinup > cd MOARforce1850 # The following sets the casename to point to for atm forcing (you could also use an editor) - > ./xmlchange DATM_CPL_CASE=b40.1850.track1.1deg.006a + > ./xmlchange DATM_CPLHIST_CASE=b40.1850.track1.1deg.006a # The following sets the align year and years to run over for atm forcing # (you could also use an editor) > ./xmlchange DATM_YR_ALIGN=1,DATM_YR_START=960,DATM_YR_END=1030 diff --git a/doc/source/users_guide/setting-up-and-running-a-case/customizing-the-clm-configuration.rst b/doc/source/users_guide/setting-up-and-running-a-case/customizing-the-clm-configuration.rst index 11e996ae5d..ec28a0d624 100644 --- a/doc/source/users_guide/setting-up-and-running-a-case/customizing-the-clm-configuration.rst +++ b/doc/source/users_guide/setting-up-and-running-a-case/customizing-the-clm-configuration.rst @@ -513,7 +513,7 @@ For running "I" cases there are several other noteworthy configuration items tha DATM_YR_ALIGN DATM_YR_START DATM_YR_END - DATM_CPL_CASE + DATM_CPLHIST_CASE ``CCSM_CO2_PPMV`` Sets the mixing ratio of CO2 in parts per million by volume for ALL CESM components to use. Note that most compsets already set this value to something reasonable. Also note that some compsets may tell the atmosphere model to override this value with either historic or ramped values. If the ``CCSM_BGC`` variable is set to something other than "none" the atmosphere model will determine CO2, and CLM will listen and use what the atmosphere sends it. On the CLM side the namelist item ``co2_type`` tells CLM to use the value sent from the atmosphere rather than a value set on it's own namelist. @@ -575,8 +575,8 @@ DATM_YR_END DATM_YR_ALIGN ``DATM_YR_START`` and ``DATM_YR_END`` determine the range of years to cycle the atmospheric data over, and ``DATM_YR_ALIGN`` determines which year in that range of years the simulation will start with. -DATM_CPL_CASE - ``DATM_CPL_CASE`` sets the casename to use for the ``CPLHISTForcing`` mode. +DATM_CPLHIST_CASE + ``DATM_CPLHIST_CASE`` sets the casename to use for the ``CPLHISTForcing`` mode. ----------------------------- Downloading DATM Forcing Data @@ -586,7 +586,7 @@ In Chapter One of the `CESM User's Guide `_ there is a section The `CLMCRUNCEP` data is uploaded into the subversion inputdata repository as well -- but as it is 1.1 Terabytes of data downloading it is problematic (*IT WILL TAKE SEVERAL DAYS TO DOWNLOAD THE ENTIRE DATASET USING SUBVERSION*). Because of its size you may also need to download it onto a separate disk space. We have done that on derecho for example where it resides in ``$ENV{CESMROOT}/lmwg`` while the rest of the input data resides in ``$ENV{CESMDATAROOT}/inputdata``. The data is also already available on: janus, franklin, and hopper. If you download the data, we recommend that you break your download into several chunks, by setting up a case and setting the year range for ``DATM_YR_START`` and ``DATM_YR_END`` in say 20 year sections over 1901 to 2010, and then use ``check_input_data`` to export the data. -The ``CPLHISTForcing`` DATM forcing data is unique -- because it is large compared to the rest of the input data, and we only have a disk copy on derecho. The DATM assumes the path for derecho of ``/glade/p/cesm/shared_outputdata/cases/ccsm4/$DATM_CPLHIST_CASE`` for the data. So you will need to change this path in order to run on any other machine. You can download the data itself from NCAR HPSS from ``/CCSM/csm/$DATM_CPLHIST_CASE``. +The ``CPLHISTForcing`` DATM forcing data is unique -- because it is large compared to the rest of the input data, and we only have a disk copy on derecho. The DATM assumes the path for derecho of ``/glade/p/cesm/shared_outputdata/cases/ccsm4/$DATM_CPLHIST_CASE`` for the data. So you will need to change this path in order to run on any other machine. -------------------------------------- Customizing via the build script files From 16d83c15cce709955a44ca75115e718e84bc6a7f Mon Sep 17 00:00:00 2001 From: Sam Rabin Date: Fri, 1 Nov 2024 12:42:17 -0600 Subject: [PATCH 5/5] Add warning box to MOAR User's Guide page. --- ...th-MOAR-data-as-atmospheric-forcing-to-spinup-the-model.rst | 3 +++ 1 file changed, 3 insertions(+) diff --git a/doc/source/users_guide/running-special-cases/Running-with-MOAR-data-as-atmospheric-forcing-to-spinup-the-model.rst b/doc/source/users_guide/running-special-cases/Running-with-MOAR-data-as-atmospheric-forcing-to-spinup-the-model.rst index cf9fbc773c..7c18cee009 100644 --- a/doc/source/users_guide/running-special-cases/Running-with-MOAR-data-as-atmospheric-forcing-to-spinup-the-model.rst +++ b/doc/source/users_guide/running-special-cases/Running-with-MOAR-data-as-atmospheric-forcing-to-spinup-the-model.rst @@ -6,6 +6,9 @@ Running with MOAR data ======================== +.. warning:: + These instructions are outdated and will not work. This page will be either updated or removed as part of the CTSM6/CLM3 release. + Because it takes so long to spinup the CN model (as we just saw previously), if you are doing fully coupled simulations with active atmosphere and ocean, you will want to do the spinup portion of this "offline". So instead of doing expensive fully coupled simulations for the spinup duration, you run CLM in a very cheap "I" compset using atmospheric forcing from a shorter fully coupled simulation (or a simulation run previously by someone else). In this example we will use the ``I1850Clm50BgcSpinup compset`` to setup CLM to run with atmospheric forcing from a previous fully coupled simulation with data that is already stored on disk on Cheyenne. There are several simulations that have high frequency data for which we can do this. You can also do this on a machine other than Cheyenne, but would need to download the data from the Earth System Grid and change the datapath similar to Example :numref:`eg-sim-data-from-prev-sim`.