CESM 1.0.2 near past initial conditions user guide
Contents
1. C compiler flags that the user wishes to set Fortran compiler flags that the user wishes to set load flags that the user wishes to set SMP Shared memory Multi processing TRUE or FALSE default is FALSE OPT Use optimized options Check for the netcdf library and include directories ifeq LIB_NETCDF null LIB_NETCDF usr local lib LIB_NETCDF usr local netcdf 3 6 3 lib endif ifeq INC_NETCDF null INC_NETCDF usr local include INC NETCDF usr local netcdf 3 6 3 include CESM 1 0 2 near past initial conditions user guide prescribing ice sheets endif Set if Shared memory multi processing will be used ifneq strip SMP SMP TRUE endif Newer makes set the CURDIR variable CURDIR shell pwd ifeq CLM ROOT nu11 ROOTDIR CURDIR else ROOTDIR shell ls 1d CLM_ROOT models 1nd clm endif CURDIR Depends CURDIR Srcfiles CURDIR Filepath users home ans021 CESM 1 0 21 0 2 scripts ccsm utils Build mkDepends Filepath Srcfiles 6 ROOTDIR scripts ccsm utils Build mkDepends Filepath Srcfiles gt Sp ici Centro Euro Mediterraneo sui Cambiamenti Climat Centro Euro Mediterraneo sui Cambiamenti Climatici OO NO CMCC Research Papers APPENDIX Il FLOW CHARTS SUMMARIZING THE PROCEDURE DESCRIBED IN THIS USER GUIDE Flow chart showing the various steps of the procedure described in the2. CMCC Research Papers 7 Generating the new initial CLM initial conditions file the 5 days CESM 1 0 2 run When running on a new platform outside of NCAR it might be necessary to regenerate the initial boundary conditions file for CLM This is due to some differences in the allocation of the processors and memory during the compilation of the model This part corresponds step 8 and step 9 on Figure 4 showing the whole procedure in Appendix Il To do so the user has to configure the namelist as shown in section 6 except for the CLM namelist in which the original option pointing at the initial boundary conditions file is modified amp clm inparm finidat USER REPOSITORY b40 1850 trackl 1deg 006 cl1m2 r 0863 01 01 00000 nc into amp clm inparm finidat This will allow the model to create a new restart file containing the CLM initial conditions adapted to the platform After this modification the user can run the B compset for 5 days only The default configuration of env run xml is already set up for a 5 day run At the end of this run the user gets a CLM restart file clm r new paleo which is used to interpolate the original CLM initial conditions file b40 1850 track1 1deg 006 clm2 r 0863 01 01 00000 nc The interpolation is performed using the interpinic package located in the CESM 1 0 2 repository CESM 1 0 2 models Ind clm tools interpinic The user will have to edit the Makefile to change the path of the
3. 14 Those changes have to be done before building the compset CESM 1 0 2 near past initial conditions user guide prescribing ice sheets Present day gx1v6 region ids file provided in CESM 1 0 2 left Bee m of gx1v6_region_ids file provided by users right 1 Southern Ocean 0 0 0 0 0 0 1 Southern Ocean 0 0 0 0 0 0 2 Pacific Ocean 0 0 0 0 0 0 2 Pacific Ocean 0 0 0 0 0 0 3 Indian Ocean 0 0 0 0 0 0 3 Indian Ocean 0 0 0 0 0 0 4 Persian Gulf 220 60 0 0 0 4 Persian Gulf 22 0 60 0 0 0 5 Red Sea 14 0 47 0 3 0e15 5 Red Sea 14 0 47 0 3 0e15 6 Atlantic Ocean 0 0 0 0 0 0 6 Atlantic Ocean 0 0 0 0 0 0 7 Mediterranean Sea 36 0 3540 0 0 y Mediterranean Sea 36 0 354 0 0 0 8 Labrador Sea 0 0 0 0 0 0 8 Labrador Sea 0 0 0 0 0 0 9 GIN Sea 0 0 0 0 0 0 9 GIN Sea 0 0 0 0 0 0 10 Arctic Ocean 0 0 0 0 0 0 10 Arctic Ocean 0 0 0 0 0 0 11 Hudson Bay 61 0 295 0 0 0 11 Black Sea 40 0 25 0 3 0e15 12 Baltic Sea 560 8 0 3 0e15 12 Caspian Sea 820 72 0 3 0e15 13 Black Sea 40 0 25 0 3 0e15 14 Caspian Sea 70 0 65 0 3 0e15 3 2 Coupler mapping files The mapping files contains informations weights etc which are used by the coupler to interpolate the ocean grid onto the atmospheric grid and vice versa The runoff map is also part of this process since to be computed it uses one of the mapping file generated The script that computes the four mapping f
4. POP sea ice CICE which are managed by the coupler Figure 1 Several spectral and finite volume grids resolutions have been developed for each component The model has been calibrated for present day Earth s topography bathymetry and extensively validated on present day climate observations One of the big advantage of this model is that the running procedure is straightforward in its present day configuration for any new user Community Earth System Model gt Parallel Ocean Program OP2 gt Climatological Slab Ocean Data Model DOCN Figure 1 CESM 1 0 2 architecture See CESM 1 0 2 webpage for more details While the latest version of CESM 1 0 2 has also been successfully tested for paleoclimate sim ulations recently its climate components are not flexible to simulate near or deep past climates requiring different topographies bathymetries relative to present day Indeed to use a different continental distribution and a different sea level each component needs substantial changes in its initial conditions files which requires an advanced knowledge of the model The procedure is highly CESM 1 0 2 near past initial conditions user guide prescribing ice sheets time consuming and has been up to now only tested on NCAR Bluefire by NCAR Paleo working group for various time periods using the local numerical tools developed in situ In order to make those kind of changes more accessible for new users the follo
5. atm bilin nc map atm to ocn bilin nc gx1v6_mis6 nc new ocean grid only used for runoff map Fortran 90 build calypso csh runoff calypso run Input gx1v6 mis6 nc rdirc 05 061026 Output map r05 to gx1v6 mis6 nc Fortran 90 make AIX csh gen domain aix Imv scrip_inb scrip in I scripdir scrip Input map ocn to atm aave nc Output domain ocn gx1v6 mis6 nc domain Ind fv09 1 25 gx1v6 mis6 nc Do not forget to set the path for the SCRIP executable in mk remap gx1v6 csh To check the consistency of the mapping files the user may use scrip test executable and namelists which are designed to produce readable NetCDF outputs from the mapping files generated NOTES AND ADVICE producing the mapping files for the coupler is not an easy task and the user should pay attention to it since if it fails for some reasons and for only one pixel the model will not be able to run with the new conditions Then given the structure of this procedure the user may have to start again from almost the beginning of the procedure see all the flow charts in Appendix II Once the mapping files have been generated the user may compute the runoff map This file is generated at 0 5 horizontal resolution and is based on the new ocean grid file computed at the pre vious step Table 4 The runoff package has to be compiled first using the script build calypso csh CESM 1 0 2 near past initial conditions user guide prescribing ice
6. 4 Various steps of the procedure described in the user guide Source Nan Rosembloom Centro Euro Mediterraneo sui Cambiamenti Climatici CO e CMCC Research Papers ZE __ ou31Vqd00e400019 uniAW xB oy Gos dew GOOLOL ML d Le Go dewyouns uab ouw3lvd ep e ee Gz 6044 oj HAUT Lx6 dew Qqasn LON ou ggzoxz6l0 eyeppub 919 Ze soge deui AJp oJs spojN92Jnos LOOH3SVO SI soge deuijes uso juupinq ido Jux juoo Aue ou31vq ep ug unsAw x6 oi Sz 60 dew ou31VGq ep e ee umAw xB oj Gz 60Aj dew ou 31VvQ epP ug SZ 60N or unsAW Lef dew ouvyiva ep e ee cz y GOAL ot uniAur xD dew opujunej uso juupinq u S LX6 0 eyepoey ou3Ivq uniKul x5 uoo uieuop owa31vq uniAur x6 sz Lxe oArpurureuop eat ureuioq urewop ueB m ouglIvd ep e ee GZL 6047 oy uniAur x6 dew Buidde oun ulewoq pue Icen jouny sally B5uiddey 1 dno09 i a pue 1 A oo szoroson Ou uniAur Laf A AE illl O O 9u 24040 SZ LX6 0N E uso 9gALxB dewes xu a gieeerzoroLOO0Z pub zuou Buiddey 1e dno yieeor3jvq uniAur 9ALxB yw Figure 5 Various steps to compute the coupler mapping files described in section 3 2 Source Nan Rosembloom pyew nuaeuleiquie ins oeueJ9lIpa y o4n3 onus CESM 1 0 2 near past initial conditions user guide prescribing ice sheets pyew
7. bnd Figure 7 Various steps to compute the atmospheric topography described in section 5 Source Nan Rosembloom Centro Euro Mediterraneo sui Cambiamenti Climatici 2013 Visit www cmcc it for information on our activities and publications The Euro Mediteranean Centre on Climate Change is a Ltd Company with its registered office and administration in Lecce and local units in Bologna Venice Capua Sassari Viterbo Benevento and Milan The society doesn t pursue profitable ends and aims to realize and manage the Centre its promotion and research coordination and different scientific and applied activities in the field of climate change study Cmcc Centro Euro Mediterraneo sui Cambiamenti Climatici
8. changed by setting environment variables USER CPPDEFS Additional USER CFLAGS Additional USER FFLAGS Additional USER LDLAGS Additional LIB NETCDF Library directory location of netcdf defaults to usr local lib INC NETCDF Include directory location of netcdf defaults to usr local include MOD NETCDF Module directory location of netcdf defaults to LIB_NETCDF USER FC Allow user to override the default Fortran compiler specified in Makefile USER FCTYP Allow user to override the default type of Fortran compiler linux and USER FC ftn only USER CC Allow user to override the default C compiler specified in Makefile linux only USER LINKER Allow user to override the default linker specified in Makefile CPP defines C compiler flags that the user wishes to set Fortran compiler flags that the user wishes to set load flags that the user wishes to set OPT Use optimized options Set up special characters null EXENAME mkgriddata RM rm Check for the netcdf library and include directories ifeq S LIB NETCDF null LIB NETCDF usr local netcdf 3 6 3 lib endif ifeq INC NETCDF null LIB NETCDF usr local netcdf 3 6 3 include endif Newer makes set the CURDIR variable CURDIR shell pwd ifeq CLM_ROOT null ROOTDIR CURDIR ROOTDIR users home ans021 BC mkgriddata else ROOTDIR shell
9. created using the package mkgriddata located in CESM 1 0 2 models Ind clm tools The package produces three files containing the land fraction the topography and a new grid file respectively The two latter are not used at all by the procedure To use the package the user has to set up the namelist and compile the routines Some modifications of the NetCDF library path and compiler name in the Makefile are necessary CESM 1 0 2 near past initial conditions user guide prescribing ice sheets Table 5 Pre processing topography for surface dataset Numerical tool Scripts Inputs Outputs NCL 10min2_05deg ncl Input topo_mis6_10min nc Output topo_mis6_05deg nc NCL create_mksrf_topo ncl Input topo_mis6_10min nc mksrf topo 10min c080912 nc Output mksrf topo 10min mis6 nc Fortran mkgriddata package Input NetCDF topo mis6 10min nc Output fracdata 10min nc griddata_10min nc not used topodata 10min nc not used Compile the package and then execute it gt mkgriddata mkgriddatanamelist gt amp mkgriddata out 4 2 Adding glaciers to the list of PFTs The ice sheets distribution is extracted form the 0 5 resolution topography interpolated at the previou step and transformed into a PFT type and landunit CLM initial conditions file considers 15 PFTs by default Figure 3 As the user can notice the type glaciers is not included into this distribution Consequently this step aims at introducing the 16th
10. nueuleiquie INS oeueJ9lIpa y o4n3 OU 100 o9jeg 1001 NS3O yepansy uso uunqr uo MN penes ejepjunsyuu ou unJ urutup odoy syw pu odoj jisxyul a e319 NI Dw L ov3 1vqruniKuiuiug eyepoey Lem EL ojo ou 31vq uniAur ape6 psyw ou31vq uniAur yd syw ou 31vq uniAur jewue sy pu i uu I 1oquBieu jsejeeu YIM sjulod pue Meu IL pu upon sy azea OJ8Z 0 Sjuiod ueqin jag ra E jouysersey yd ppe 0 0 01 49S pue HAS 10 Se qeuueA jseAJeu ppy 9u 31 vq unikur 3ewue syu ou 31vq unikul yd Ueu ou 31vq unaAur 1eroejB jisyuu gg u 6Z6090 J8102 5 syu 9u 0 90609 098 91 esnpue syw ou gcy0S0 ewue Uu 064 Uu 1ieAuoo NN ENT 3 ouunjiAur Bepco eor odoi Jesejeq eoeungs ejyeppubyxuu ouuu unsAw et odo J Figure 6 Various steps to compute the land surface dataset files described in section 4 Source Nan Rosembloom CMCC Research Papers Centro Euro Mediterraneo sui Cambiamenti Climatici topo bnd topo ice myrun 10min nc Gridfile fv 0 9x1 25 nc Landmask landm coslat nc Make ross true definesurf mod landm coslat ncl topo myrun remap 09x25 mod DATE nc cam buildnml csh topo
11. user guide Source Nan Rosembloom m Various steps to compute the coupler mapping files described in section 3 2 Source Nan Rosembloom Various steps to compute the land surface dataset files described in section 4 Source Nan Rosembloom Various steps to compute the atmospheric topography described in section 5 Source Nan Rosembloom CESM 1 0 2 near past initial conditions user guide prescribing ice sheets Legend USER INPUT Paleo tools land ocn mask 1deg nc CESM1 0 tools topo ice 10min nc Required if using CLM restart files with new landcover change kmt ncl Step1 LS or ox KMT myrun kmtEd mk remap csh Step2 LS mk runoff remap csh I coupler mapping genrunoff ocn domain myrun pns genedomaln Ind domain myrun fracdata myResolution Step 4 mkgriddata fracdata 10min myrun Step 5 convert mksrf F90 1 or mksrf myrun files paleo mkraw csh Step 6 mksurfdata surface dataset myrun Step7 LS definesurf bnd topo myrun Ee i Step 8 5 day CESM clm r new paleo map y ae clm r spun up state mapped Step 9 interpinic to new paleo map y Step 10 Production CESM Figure
12. Ccmocc Centro Euro Mediterraneo sui Cambiamenti Climatici Research Papers Issue RP0168 April 2013 ANS Numerical Applications and Scenarios Division By Florence Colleoni Centro Euro Mediterraneo sui Cambiamenti Climatici CMCC Bologna Italy florence colleoni cmcc it We thank Nan Rosembloom and Bette Otto Bliesner for their technical and scientific support to learn the procedure described in this guide The research leading to these results has received funding from the Italian Ministry of Education University and Research and the Italian Ministry of Environment Land and Sea under the GEMINA project CESM 1 0 2 near past initial conditions user guide prescribing ice sheets SUMMARY The Community Earth System Model has been developed and is maintained by NCAR At this stage of the report the CESM 1 0 2 includes atmosphere land ocean sea ice and a partially coupled ice sheets model Several grid resolutions have been developed for each component and for present day Earth s topography bathymetry and one of the big advantage of this model is that the running procedure is straightforward in its present day configuration for any new user However the CESM 1 0 2 components are not flexible to simulate near or deep past climates which require a different topography bathymetry relative to present day Indeed to simulate a different continental distribution and a different sea level each component needs substanti
13. NetCDF libraries and will have to compile the routines To execute interpinic gt interpinic i b40 1850 trackl 1deg 006 c1m2 r 0863 01 01 00000 nc 0 clm r new paleo The file clm r new paleo will be then overwritten with the variables contained in b40 1850 track1 1deg 006 clm2 r 0863 01 01 00000 nc that is why we recommend to re name it for example b40 1850 track1 1deg 006 clm2 r 0863 01 01 00000 interp paleo nc Finally the user can run the true paleo experiment pointing at the new interpolated CLM file in the finidat field of the CLM namelist CESM 1 0 2 near past initial conditions user guide prescribing ice sheets USEFUL LINKS RELATED TO CESM 1 0 2 PALEOCLIMATE MODELLING During the entire procedure and for the first paleo runs found the following Wiki pages very useful for the various crashes of the components of CESM 1 0 2 Paleo Documentation on the CESM 1 0 2 dedicated website the user can find some further documentation and advices when configuring the run for paleo times The Paleo working group have created a wiki page which accessible to anybody The following websites are dedicated to paleo datasets and ice sheet configurations used to create paleo topographies PMIP3 Paleoclimate Models Intercomparison Phase 3 CE 5G W R Peltier Last glacial deglaciation 21k Ok ice sheets reconstructions Peltier 2004 Ice Cores Gateway to get the lastest GHGs records available for various parts of the w
14. PFT in the new initial boundary conditions file All the scripts and input output files are reported in Table 6 Three files are created the land ice distribution the glaciers PFT type and the new landuse distribution The Fortran 90 routine is called convert mksrf F90 and uses three pre existing files from CESM 1 0 2 containing the present day glaciers mask the present day landunit distribution and present day landuse map in our compset the default distribution corresponds to that of pre industrial Indeed in CLM a type of landunit is attributed to each pixel Figure 3 In total there are five declared landunits Urban Lake Wetland Glacier and Vegetated The Vegetated type is further divided into PFTs To add some ice sheets over the ground the user have to declare how much of each pixel will be Glacier and or vegetated This is exactly what convert mksrf F90 does The routine is based on a template routine in which the user has to point at the original CESM 1 0 2 Centro Euro Mediterraneo sui Cambiamenti Climatici C2 Centro Euro Mediterraneo sui Cambiamenti Climatici CMCC Research Papers Numerical tool New PFTs distribution adding glaciers to the landcover Scripts Inputs Outputs NCL convert mksrf F90 Input topo mis6 05deg nc mksrf topo 10min c080912 nc Output mksrf glacier mis6 nc mksrf pft mis6 nc mksrf_landwat_mis6 nc NCL add_harvest ncl Input mksrf_pft_mis6 nc mksrf_land
15. al changes in its initial conditions files which require an advanced knowledge of the model In order to make those kind of changes accessible for new users the following document aims at proposing a relatively simple procedure to modify the initial conditions files for the coupled atmosphere land ocean sea ice compset of the CESM 1 0 2 B compset This procedure was mainly developed at NCAR but never tested before on the different super computing platforms and outside of NCAR The guide presented here have been successfully tested on CMCC IBM Power 6 platform taking as example a glaciation configuration However this process is by far non automatic and requires some substantial manual work at each stage of the procedure Finally following this procedure does not provide any guarantees that the simulations will be successful Centro Euro Mediterraneo sui Cambiamenti Climatici d CMCC Research Papers INTRODUCTION 1 The Community Earth System Model The Community Earth System Model CESM 1 0 2 is an Earth System Model composed of an AGCM CAM an OGCM POP a land model CLM a sea ice model CICE and a dynamical ice sheets model CISM The CESM 1 0 2 has been developed between NCAR and LANL and is maintained by NCAR The code and its documentation are available on the CESM 1 0 2 website http www CESM 1 0 2 ucar edu At this stage of the report the CESM 1 0 2 fully couple compset B compset includes atmosphere CAM land CLM ocean
16. aneo sui Cambiamenti Climatici O1 Centro Euro Mediterraneo sui Cambiamenti Climatici E CMCC Research Papers finite volume 0 9x1 25 atmospheric resolution and displaced pole 1 ocean resolution f09 g16 see the CESM 1 0 2 user guide for more details on the supported resolutions The instructions to build the compset are provided in the CESM 1 0 2 User Guide This process will automatically download all the files required by all the components of the compset to run with the pre defined configurations already implemented in CESM 1 0 2 Once the user has built the compset he can proceed with the steps described in the forthcoming sections Do not clean up the compset directory since it will be used to create the 5 days initial conditions land file at run time see section 7 Appendix II Figure 4 step 7 2 Pre processing the topography Using a very clean topography from the beginning is particularly important for the rest of the procedure especially for the ocean and for the coupler For that reason the user should spend as much time as necessary to obtain a satisfying initial topography What does it mean It means removing all the small islands that might create problems during the various interpolations steps required during the entire procedure described in this guide Indeed the initial topography file should be at 10 min horizontal resolution During the various steps this file will be interpolated at 0 5 at 1 and finally at t
17. at 0 5 x0 5 This is done by using the script 10min2 05deg ncl To execute the script in a Terminal write gt ncl 10min2_05deg ncl Be sure that the following variables are computed in the indicated ranges ICE 0 100 LANDFRACT 0 1 LANDMASK 0 1 For step 4 4 the user also needs an additional topographic file at 10 min resolution which contains a variable named TOPO_BEDROCK This is done using the script create_mksri_topo ncl This script also needs the original mksrf topo 10min nc file downloaded from the NCAR Bluefire repositories Table 5 To execute the script do gt ncl create_mksrf_topo ncl NOTE the bedrock topography corresponds to an ice free topography Those informations are available for present day e g ETOPO2 and ETOPO1 but for example in the compset of glaciations if the user only knows about the surface elevation and the landice distribution but does not have any information about the ice thickness the bedrock topography cannot be retrieved However this information is only necessary in the compset of running a dynamical ice sheets model which requires both ice thickness and bedrock topography as input fields Since no ice sheet model has been implemented yet in CESM 1 0 2 at the time of this user guide the bedrock topography is not necessary to run the simulations Consequently TOPO BEDROCK is set equal to TOPO ICE in create mksrf topo ncl Finally a new land fraction file at 10 min resolution has to be
18. d when changing the ocean topography file changes occur in the region mask and in the overflow locations as well in POP the locations of the overflows for present day bathymetry are prescribed as initial input in CESM 1 0 2 models ocn pop 2 input templates In the present day region mask file each basin and marginal sea is assigned a value between 1 to 14 You can find the present day configuration in the main directory of the CESM 1 0 2 model CESM 1 0 2 models ocn pop2 input templates The original gx1v6 region ids file provided in the CESM 1 0 2 for present day is shown in Table 3 If the topo provided by the user induces modifications in the present day basins distribution no Baltic Sea no Hudson Bay for example the previous value assigned to the basins has to be re assigned An example is given in Table 3 illustrating our glaciation compset The Baltic Sea as well as the Hudson Bay have been removed and filled with ice The basins no longer exist in the new ocean topography file and as a consequence the user has to modify the list and re assign values to the Black Sea and the Caspian Sea Note that a negative value is indicative of a marginal sea Those modifications are necessary because the POP ocean model checks for the total number of ocean basins prescribed and takes the absolute value of the maximum number indicated in the gx1v6 region ids file In our compset this number is abs 12 12 for present day it would be abs 14
19. he Last Glacial Maximum Some of them have then been cleaned and adjusted to a more general goal and to test a different glacial topography 140 kyrs ago All those scripts have been ported on the IBM CALYPSO supercomputer AIX operative system and partly run in interactive mode or in queue mode It is important to understand that the procedure starts with the computation of ocean and coupler initials conditions on which most of the surface datasets are based In all the tables of this document the files generated from the scripts or provided by the user are distinguished from the original raw grid files or others directly coming from CESM 1 0 2 by using the following color code blue pre existing CESM 1 0 2 raw data files red user provided files orange computed files during the procedure 0 Software requirements Fortran 90 m NetCDF Fortran libraries NCAR Command Language download at http www ncl ucar edu m Ncview 1 Building a new CESM 1 0 2 B compset Since most of the scripts that will be used in this procedure are generated on top of pre existing present day CESM 1 0 2 files for the various compsets at various resolutions itis necessary to download them from NCAR servers to first build a compset for which he will cre ate new boundary conditions In this manual the explanations are given for B compset atm Ind ocn sic using pre industrial period files B1850 compset LU Centro Euro Mediterr
20. he CESM 1 0 2 compset resolution e g f09 g16 T31 gx3v7 see the CESM 1 0 2 user guide for more details on the supported resolutions Table 1 Pre processing initial topography script and associated files Numerical tool Scripts Inputs Outputs NCL mk140kTopo ncl Input USGS gtopo30 10min nc Relief 140k 10min nc topography at 10min res landice mis6 nc ice mask Output topo mis6 10min nc htopo ice landfract landsmask variance Most of the scripts that will be used in the following steps are based on pre existing CESM 1 0 2 initial conditions files to which the differences provided by the user new input conditions are added This is the compset for the initial topography file To create this file we use the script mk140kTopo ncl This script needs the USGS present day 10 min topography file the user new topography with a different sea level for example and the new land ice distribution ice sheets and glaciers if different from present day one The input and output files are reported in Table 1 and the execution time of the script is reported in Table 9 To execute the script gt ncl mk140kTopo ncl CESM 1 0 2 near past initial conditions user guide prescribing ice sheets 3 Ocean and coupler initial conditions files This part is dedicated to the computation of the initial conditions for POP2 ocean and CPL6 coupler The whole procedure is described bellow and illustrated by the flow chart in Appendix Il Fig
21. his time Note that sea level is also lower by about 130 m SLE relative to present day Creating initial conditions for Near Past or Deep Past has different implications For Deep Past changes in the surface topography land cover but also of the ocean bathymetry and basins decomposition require a large amount of work both to create the initial files and to modify some Centro Euro Mediterraneo sui Cambiamenti Climatici GO Centro Euro Mediterraneo sui Cambiamenti Climatici E CMCC Research Papers specific pre existing files into the model itself set up with present day characteristics For Near Past the ocean bathymetry is kept at its modern state only some of the oceanic basins are removed from the pre existing modern decomposition due to sea level drops and of course the land sea mask and surface topography are modified depending on whether or not the user introduces some ice sheets or topographic features The conceptis to add some slight differences relative to present day global topography in order to reduce the number of changes introduced in the model and probable inconsistencies between the various components of the CESM 1 0 2 In this user guide we focus on how generating the initial boundary conditions for near past climates and in particular how to change sea level and prescribe ice sheets over North America and Eura sia in the CESM 1 0 2 fully coupled compset B compset Those changes implicate s
22. hose optimisations the run could last for hours and or days The executable is optimised and can be submitted to a queue On the CALYPSO platform the batch script is mksurfdata calypso run bin csh f SVN Id SVN SURLS BSUB n 64 BSUB R span ptile 64 BSUB q poe medium BSUB a poe BSUB o poe stdout J BSUB e poe stderr J BSUB J maprunoff BSUB W 2 00 setenv LID date y m d H M S Setenv OMP NUM THREADS 64 cd fis01 cgd cseg csm mapping makemaps r05 your working dir set SRCDIR users home ans021 BC surface bc mksurfdata echo start computing surface dataset date time SRCDIR mksurfdata lt mksurfdata namelist amp mksurfdat out echo finished computing surface dataset date tail 200 out LID In this package one of the input files pftdyn hist simyr1850 txt is particularly important and de termines if the user will compute a surface dataset for dynamical vegetation use or for stationary conditions A corresponding file to compute dynamic vegetation is called pftdyn hist simyr1850 2005 txt and contains the name of the vegetation distribution for each year from 1850 to 2005 Centro Euro Mediterraneo sui Cambiamenti Climatici zl e Centro Euro Mediterraneo sui Cambiamenti Climatici CMCC Research Papers included In this guide we compute static vegetation conditions A crucial aspect of this file is its format since the CLM Fortran code reads it with a specific format sta
23. i else FFLAGS O2 qmaxmem 1 Q LDFLAGS Q endif CFLAGS q64 g S CPPDEF 02 FFLAGS cpp path CFLAGS cpp path ifeq SMP TRUE FC x1f90 r FFLAGS qsmp omp LDFLAGS qsmp omp else FC xlf90 endif endif CMCC Research Papers SCRIP Makefile extracts ici bin csh Makefile for interpolation code CVS Id makefile v 1 7 2000 04 19 21 46 44 pwjones Exp COMPILE xlf90 COMPILE 90 FLAGS 03 FLAGS 03 r10000 q64 I usr local include FLAGS g DEBUG div check 3 subscript check ON trap uninitialized ON verbose runtime ON r10000 64 I usr lo LIB L usr local netcdf 3 6 3 lib lnetcdf INCLUDE usr local netcdf 3 6 3 include SRCDIR EXEDIR Centro Euro Mediterraneo sui Cambiamenti Climat Gen domain Makefile extracts bin csh fv SVN Id make AIX csh 6670 2007 09 28 21 55 152 kauff SVN SURL https svn ccsm models cgd ucar edu tools mapping gen domain trunk make AIX csh set SRCDIR xlf90 02 qstrict qmaxmem 1 qrealsize 8 qarch auto q64 qsuffix f F90 o gen_domain aix SSRCDIR gen domain F90 I usr local include L usr local netcdf 3 6 3 lib lnetcdf mkgridata Makefile extracts This Makefile is for building clm tools on AIX Linux with pgf90 or 1 95 compiler Darwin or IRIX platforms CESM 1 0 2 near past initial conditions user guide prescribing ice sheets These macros can be
24. iles is the shell script mk remap gx1v6 csh This script needs the SCRIP software which handles the interpolation of the various grids SCRIP webpage Once downloaded the user has to compile SCRIP editing some of the paths in the Makefile To perform the interpolation between ocean and atmosphere mk_remap_gxiv6 csh needs the original ocean and atmosphere grid files and the new ocean topography kmt_mis6 nc generated at the previous step All the inputs and outputs files are reported in Table 4 BE AWARE mk_remap_gxiv6 csh has to be executed two times This is because two of the mapping files are computed using a conservative interpolation method while the two others are generated using a bilinear interpolation method In the script one of the two methods is commented and the user has to switch them on off to get the four mapping files one time for conservative interpolation Imv scrip ina scrip_in I scripdir scrip one time for bilinear interpolation Centro Euro Mediterraneo sui Cambiamenti Climatici CO Centro Euro Mediterraneo sui Cambiamenti Climatici CMCC Research Papers Table 4 New coupler mapping runoff and domain files Numerical tool Scripts Inputs Outputs shell SCRIP mk remap gx1v6 csh Input topo mis6 10min nc fv0 9x1 25_070727 nc CAM grid at 0 9x1 25 res horiz grid 20010402 ieeer8 POP present day horizontal grid Output map ocn to atm aave nc map atm to ocn aave nc map ocn to
25. in the script present day bathymetry and topography are preserved over the unchanged areas Then edit the script change kmt new ncl to point to the new topography 1x1 nc file and execute it gt ncl change kmt new ncl As reported in Table 2 change kmt new ncl also needs the original present day POP topography Centro Euro Mediterraneo sui Cambiamenti Climatici zl e Centro Euro Mediterraneo sui Cambiamenti Climatici E CMCC Research Papers regions and horizontal grid files provided directly for the resolution of interest to the user in the csm inputdata ocn pop2 grid directory The execution time of the scripts is detailed in Table 9 Table 2 New ocean topography and region mask files Numerical tool Scripts Inputs Outputs NCL 10min2 1x1deg ncl Input topo mis6 10min nc Output topo mis6 1x1 nc NCL change kt new nd Input topo mis6 1x1 nc topography at 1 res topography 20090204 ieeei4 POP present day topo region mask 20090205 ieeei4 POP present day ocean basins botz grid 20010402 ieeer8 POP present day horizontal grid Output kmt gx1v6 mis6 ieeei4 region mask gx1v6 mis6 ieeei4 MIS6kmt nc file to check for disturbing pixels A NetCDF file containing the main variables generated by change kmt new ncl is also created to check whether the new land sea mask and region mask are correct Moreover it is important to check also the number of basins contained in the new oceanic region mask Indee
26. ion the script mod landm coslat ncl further modifies the new topography interpolated on the final atmospheric grid All those files are reported in Table 8 and the procedure is described in Appendix II Figure 7 To execute the package first the user may compile it and then gt definesurf t topo mis6 lO0min nc g fv 0 9x1 25 nc l landm coslat nc newtopo nc Table 8 Creating CAM initial conditions Numerical tool Scripts Inputs Outputs Fortran definesurf package Input NetCDF fv 0 9x1 25 nc landm coslat nc topo mis6 10min 111021 nc Output topo mis6 0 9x1 25 remap 111101 nc NCL mod_landm _coslat ncl Input topo_mis6_0 9x1 25_remap 111101 nc Output topo_mis6_0 9x1 25_remap 111101 mod nc BUGS A syntax bug was fixed in the routine map2f f90 This bug might have been corrected in the latest version of the code The user may contact NCAR directly to get a more recent version Line 926 SC j jc min 1 tmp gt old version SC j jc min 1 0d0 tmp new version fixed bug Centro Euro Mediterraneo sui Cambiamenti Climatici CO Centro Euro Mediterraneo sui Cambiamenti Climatici NO CMCC Research Papers Line 951 se j jc min 1 tmp gt old version se j jc min 1 0d0 tmp new version fixed bug Finally to correct the gradual land fraction the user has to edit the script mod landm coslat ncl to correct the areas where some new land have been added o
27. ls 1d CLM ROOT models lnd clm endif CURDIR Depends CURDIR Srcfiles CURDIR Filepath SMP Shared memory Multi processing TRUE or FALSE default is FALSE Centro Euro Mediterraneo sui Cambiamenti Climatici CO Centro Euro Mediterraneo sui Cambiamenti Climat CMCC Research Papers users home ans021 CESM 1 0 21 0 2 scripts ccsm utils Build mkDepends Filepath Srcfiles gt mksurfdata Makefile extracts lf95 compiler Darwin or USER CPPDEFS Additional USER CFLAGS Additional USER FFLAGS Additional USER LDLAGS Additional Set up special characters null EXENAME mksurfdata RM rm This Makefile is for building clm tools on AIX Linux with pgf90 or IRIX platforms These macros can be changed by setting environment variables LIB NETCDF Library directory location of netcdf defaults to usr local lib INC NETCDF Include directory location of netcdf defaults to usr local include MOD NETCDF Module directory location of netcdf defaults to LIB_NETCDF USER FC Allow user to override the default Fortran compiler specified in Makefile USER FCTYP Allow user to override the default type of Fortran compiler linux and USER FC ftn only USER CC Allow user to override the default C compiler specified in Makefile linux only USER LINKER Allow user to override the default linker specified in Makefile CPP defines
28. m to ocn state mapping file for states char gt entry id MAP A2OS FILE value map fv09 1 25 to gxlv6 bilin da nc ocn to atm mapping file for fluxes char entry id MAP O2AF FILE value map gxi1v6 to fv09 1 25 aave da nc gt ocn to atm mapping file for states char entry id MAP O2AS FILE value map gx1v6 to fv09 1 25 aave da nc gt runoff 5 degree to ocn mapping file char gt entry id MAP R20 FILE R05 value map r05 to gxl1v6 mis6 nc gt Once the mapping files have been pointed by the user configure the compset configure compset 6 2 Coupler namelist cpl buildnml csh To set up the orbital forcing the epoch of the simulation is specified in time A D 1950 time For example for the penultimate glaciation that occurred 140 kyrs BP the time will be orb iyear ad 138050 Centro Euro Mediterraneo sui Cambiamenti Climatici Centro Euro Mediterraneo sui Cambiamenti Climatici CMCC Research Papers For past time the value is negative 6 3 CAM namelist cam buildnml csh To initialise the atmospheric component the user needs to set the new topography from section 5 The user may also changes the values of the GHGs according to the epoch considered Here the values are taken from CO CH and NO ice cores records retrieved from EPICA Dome C East Antarctica and corresponds to 140 kyrs BP amp cam inparm bnd topo SDIN LOC ROOT atm cam to
29. ns021 mksurf rawdata mksrf soitex 101evel c010119 nc mksrf forganic users home ans021BC mksrf_organic 10level 0 5deg_mis6 nn nc mksrf flanwat users home ans021 BC surface bc surf ncl mksrf lanwat mis6 nn 111021 nc mksrf fmax users home ans021 BC surface bc surf ncl mksrf fmax mis6 nn 111021 nc mksrf fglacier users home ans021 BC surface bc surf ncl mksrf glacier mis6 nn 111021 nc mksrf furban users home ans021 BC surface bc surf ncl mksrf urban mis6 111021 nc mksrf fvegtyp users home ans021 BC surface bc surf ncl mksrf pft mis6 harvest nn 111021 nc mksrf fsoicol users home ans021 BC surface bc surf ncl mksrf soilcol mis6 nn 111021 nc ksrf flai users home ans021 BC surface bc surf ncl mksrf lai global mis6 nn 111021 nc 8 ksrf ftopo users home ans021 BC surface bc surf ncl mksrf topo 10min mis6 111021 nc 3 CESM 1 0 2 near past initial conditions user guide prescribing ice sheets mksrf ffrac users home ans021 BC mkgriddata fracdata_1080x2160 nc mksrf fvocef users home ans021 mksurf rawdata mksrf vocef c060502 nc mksrf firrig mksrf fdynuse pftdyn hist simyr1850 txt outnc double true After some modifications in the Makefile the user must compile the package following those options in the Makefile SMP TRUE then to compile gt gmake SMP TRUE j 64 It is critical to follow those recommendations to run the executable in a reasonable time Without t
30. orld 2 Centro Euro Mediterraneo sui Cambiamenti Climatici O1 CMCC Research Papers APPENDIX 0 EXECUTION TIME OF THE SCRIPTS USED IN THIS USER GUIDE Table 9 Computational time estimates on CALYPSO IBM power 6 o platform Scripts Execution time o 1 z mk140kTopo ncl lt 5 min o 10min2_1deg ncl lt 5 min E change kmt new ncl lt 5b min mk_remap_gx1v6 csh lt 5min gen_domain aix lt 5 min 5 runoff calypso run lt 20 min o 10min2 05deg ncl 5 min o D mkgridata 5min g create_mksrf_topo nc 5 min 9 convert mksrf lt 5 min ES add harvest ncl 5 min nn fill ncl lt 5 min create urban ncl lt 5b min Lu mksurfdata 20 min several hours g definesurf lt 5 min S mod_landm_coslat ncl lt 5 min o CESM 1 0 2 near past initial conditions user guide prescribing ice sheets APPENDIX I MAKEFILES AIX specific options common to all Makefiles extracts Architecture specific flags and rules ifeq UNAMES AIX CPPDEF DAIX DFORTRAN SAME cpre null WFE D null FPPFLAGS patsubst D cpre CPPDEF LIB NETCDF usr local lib64 r4i4 LIB NETCDF usr local netcdf 3 6 3 lib FFLAGS c I INC_NETCDF q64 qsuffix f f90 qsuffix f f90 cpp F90 FPPFLAGS g qfullpath LDFLAGS L LIB NETCDF lnetcdf q64 ifneq OPT TRUE FFLAGS qinitauto FF911299 gflttrap ov zero inv en C Centro Euro Mediterraneo sui Cambiamenti Climatic
31. po topo mis6 0 9x1 25 remap mod nc amp chem surfvals nl ch4vmr 791 6e 9 co2vmr 284 7e 6 fllvmr 12 48e 12 fl2vmr 0 0 n2ovmr 275 68e 9 6 4 CLM namelist clm buildnml csh The user has to change the value of CO in agreement with that set up in CAM namelist above Since in this example we are modelling a past glaciation the option urban hac is switched off we removed all the urban landunit from the surface dataset in section 4 3 amp clm_inparm co2_ppmv 284 7 fatmlndfrc SDIN_LOC_ROOT 1nd clm2 griddata fracdata_0 9x1 25_gxlv6_mis6 nc fsurdat SDIN_LOC_ROOT 1nd clm2 surfdata surfdata_192x288_mis6 nc urban_hac OFF 6 5 POP namelist pop2 buildnml csh As for CAM namelist the user has to indicate the new topographic and ocean basins computed in section 3 1 D identify all gxlv6 datasets residing in DIN LOC ROOT ocn pop CESM 1 0 2 near past initial conditions user guide prescribing ice sheets set regionmask filename SDIN LOC ROOT ocn pop gx3v7 grid region mask mis6 ieeei4 set topography filename DIN LOC ROOT ocn pop gx3v7 grid kmt gxi1v6 mis6 ieeei4 6 6 CICE namelist cice buildnml csh Since CICE shares the same grid with POP the topography has to be consistent amp grid nml kmt file SDIN LOC ROOT ocn pop gx3v7 grid kmt gxiv6 mis6 ieeei4 Centro Euro Mediterraneo sui Cambiamenti Climatici GO e Centro Euro Mediterraneo sui Cambiamenti Climatici NO N
32. r removed in the new topography for example the Bering Strait To execute gt nclmod landm coslat ncl The final output is the new topography file that will be directly red by the CESM 1 0 2 during the initialisation of the run The initialisation is performed from whatever cami ic nc file the default CAM initial condition file The atmosphere will quickly adjust to the new topography CESM 1 0 2 near past initial conditions user guide prescribing ice sheets 6 Setting the namelists B compset In this final section are indicated the namelists fields where the user has to prescribed the new initial conditions files computed along the entire procedure First of all the user has to indicate to the CESM 1 0 2 where are located the new files Since all the default input files for the CESM 1 0 2 runs are located in csm inputdata used to put them there as well because it limits the changes introduced into the namelists When the B compset is created the first script to be modified is env conf xml Then the compset is configured and the user may edit the namelists located in USERcompset Buildconf see CESM 1 0 2 user guide 6 1 Coupler mapping files env conf xml The user has to substitute the default mapping files by the ones computed in section 3 2 lt atm to ocn flux mapping file for fluxes char gt entry id MAP A2OF FILE value map fv09 1 25 to gxlv6 aave da nc gt at
33. script add harvest ncl that uses the new PFTs distribution mksrf pft mis6 nc created at the previous step Due to the new distribution of the glaciers and harvest PFTs some of the pixels could have remained empty To fill them the user has to execute the script nn fill nc which corresponds to a near neighbour algorithm filling the empty pixels by using their nearest PFTs and soil properties and computes all the soil properties This step uses all the pre existing CESM 1 0 2 soil properties files as for example the vertical distribution of organic matter the soil texture the LAI etc Those files are listed in Table 6 Finally since for the near past and deep past simulations there are no urban areas the user has to remove the urban landunit see Figure 3 and substitute it by vegetated areas to allow CLM to recreate some consistent hydrological conditions during the run This final step is performed by the script create urban ncl which uses the modern urban areas distribution and the combined new PFTs distribution including the harvest areas crop computed at the first step of this section IMPORTANT in the script create urban ncl the user have to set pct_urban 0 4 4 Creating CLM initial conditions file The files obtained in the previous step 4 1 to 4 3 are all combined to create the new surface dataset that will constitute the input file to initialise CLM Those files will be pointed in the namelists before Cen
34. sheets The namelist runoff map gx1 nml has to be set up properly as following amp input nml gridtype rtm file roff rdirc 05 061026 file ocn gxiv6 mis6 nc filenn map nn gx3v7 nc file smooth map smoother gx3v7 nc file new map_r05_to_gx3v7_mis6 comb21k 120618 nc title runoffmap r05 gt gx1v6 140k full ice coverage in NH eFold 1000000 0 rMax 300000 0 The runoff is then computed executing the batch script runoff calypso run The computation time is larger than 5 min that is why it is recommended to avoid running interactively gt bsub lt runoff calypso run The penultimate step of this section is the computation of the land and oceanic domain files using the gen_domain package First the namelist gen domain nml with the new mapping files The user may also edit the Makefile to specify the NetCDF library and the Fortran compiler To compile and execute the package do gt make AIX csh gt gen domain aix lt gen domain nml gt gen_domain out Finally from the land domain file domain Ind fv09 1 25 gx1v6 nc the land fraction file at the run resolution here fv 0 9x1 25 can be created This file is generated through the mkgriddata package CESM 1 0 2 models Ind clm tools The package produces three files containing land fraction topography and a new grid file The two latter are not used at all by the procedure neither during the run time To use the package
35. tement A125 1x I4 users home ans021 BC surface bc surf ncl mksrf pft mis6 harvest nn 111021 nc 1850 BE SURE when modifying the absolute path of this file that the format is respected Table 7 Computing CLM initial conditions file Numerical tool Scripts Inputs Outputs Fortran mksurfdata package Input NetCDF griddata_0 9x1 25_070212 nc mksrf soitex 10level c010119 nc mksrf vocef c060502 nc fracdata_1080x2160 nc mksrf glacier mis6 nn 111021 nc mksrf lanwat mis6 nn 111021 nc mksrf urban mis6 111021 nc mksrf organic 10level 0 5deg mis6 nn 111021 nc mksrf_fmax_mis6 nn 111021 nc mksrf_pft_mis6 harvest nn 111021 nc mksrf soilcol mis6 nn 111021 nc mksrf_lai_global_mis6 nn 111021 nc mksrf_topo 10min mis6 111021 nc pftdyn_hist_simyr1 850 txt Output surfdata pftdyn_0192x0288 nc surfdata_0192x0288 nc CESM 1 0 2 near past initial conditions user guide prescribing ice sheets 5 Atmosphere initial conditions The last CESM 1 0 2 component for which the user has to create new initial conditions is CAM The procedure uses the definesurf package This package is based on a pre existing master T42 file landm_coslat nc containing the present day topography land fractions to the coastlines on the atmospheric grid on which the user wants to interpolate his new topography here fv_0 9x1 25 nc and the user s input land fraction topography at 10 min resolution obtained from section 2 To keep consistent with the gradual land fract
36. the user has to set up the namelist and compile the package Some modifications of the NetCDF library path and compiler name in the Makefile are necessary See the section 4 1 and Table 5 for more details BE AWARE that the mkgriddata package produces coordinates that sometimes do not completely match with the coordinates of the surfdata nc file To avoid this problem the user just has to insert the CLM grid file in the namelist The routines will force the land fraction to be calculated on the CLM grid Some instructions are detailed in the README file included into the mkgridata package This is not necessary when generating the land fraction at 10 min resolution as detailed in Section 4 1 Centro Euro Mediterraneo sui Cambiamenti Climatici NO Centro Euro Mediterraneo sui Cambiamenti Climatici CMCC Research Papers 4 Land initial conditions In this section the final CLM initial surface data file will be computed at 0 5 resolution For that reason the initial 10 min topography will be interpolated at 0 5 resolution However to create the final CLM initial surface data file an additional topographic file at 10 min resolution including some bedrock informations has to be created The flow chart in Appendix II Figure 6 illustrates the various steps of this section 4 1 Pre processing topography For steps 4 2 to 4 3 the initial pre processed topography at 10 min resolution used in step 2 has to be interpolated
37. tro Euro Mediterraneo sui Cambiamenti Climatici O1 Centro Euro Mediterraneo sui Cambiamenti Climatici CMCC Research Papers Landunit n 0 Bare Glacier Wetland Vegetated Lake Urban Tree Columns 1 Needleleaf Evergreen Temperate 2 Needleleaf Evergreen Boreal Soil 3 Needleleaf Deciduous Boreal Typel 4 Broadleaf Evergreen Tropical 5 Broadleaf Evergreen Temperate 6 Broadleaf Deciduous Tropical 7 Broadleaf Deciduous Temperate 8 Broadleaf Deciduous Boreal Herbaceous Understorey 9 Broadleaf Evergreen Shrub Temperate 10 Broadleaf Deciduous Shrub Temperate 11 Broadleaf Deciduous Shrub Boreal 12 C3 Arctic Grass 13 C3 non Arctic Grass 14 C4 Grass 15 Crop PFTs Figure 3 CLM landcover pixel decomposition Source from http www CESM 1 0 2 ucar edu models clm surface heterogeneity html compiling and running the B compset see section 6 To create new surface initial conditions a special package mksurfdata has been released and is located in the CESM 1 0 2 directory CESM 1 0 2 models land clm tools This package combines all the files created in the previous steps into a unique file that will be given as input to CLM First of all the user has to set up the namelist mksurfdata namelist according to the input files listed in Table 7 amp clmexp mksrf fgrid users home ans021 csm inputdata lnd clm2 griddata griddata 0 9x1 25 070212 nc mksrf fsoitex users home a
38. ubstantial modifications at all levels for all components Beside the model itself is particularly sensitive to inconsistencies between the grids of the various climatic component and new land sea masks Indeed CAM and CLM share the same grid CICE and POP share the same grid During the first stage of the initialization process the coupler checks that the land sea masks computed for CAM and CLM matches the one computed for POP and CICE While this first stage is successful the user can hope that his initial conditions are not too unstable and that the model will not crash immediately NOTA BENE when everything get successful the user is in total state of happiness and can eventually enjoy and party most of his problems are solved Florence Colleoni CESM 1 0 2 near past initial conditions user guide prescribing ice sheets NEW INITIAL CONDITIONS FILES The user can have an overview of the whole procedure in Appendix II Figure 4 For each step of this guide the scripts the input and output files are listed in the different Tables and the settings and execution are extensively detailed Finally some of the Makefiles adapted to the IBM computing platform CALYPSO CMCC Italy are attached in Appendix The user may be aware that only few changes in the Makefiles have been necessary since CALYPSO is almost similar to NCAR s BlueFire platform All the scripts ported on CALYPSO were initially developed by Nan Rosembloom NCAR for t
39. ure 5 In this section seven files are generated new land sea mask a region mask distribution of the various oceanic basins and marginal seas the coupler mapping files x4 handle the interpolation from to the oceanic grid to from the atmospheric grid m new oceanic runoff distribution m the land and oceanic domains The execution time of the all the scripts used in this section is detailed in Table 9 3 1 Ocean topography and region mask First of all the initial pre processed topography at 10 min resolution has to be interpolated at 1 x1 This is done by using the script 10min2 1x1deg ncl To execute the script gt ncl 10min2_1xideg ncl Be sure that the following variables are computed in the indicated ranges ICE 0 100 LANDFRACT 0 1 LANDMASK 0 1 The new land sea mask and the ocean region mask are created by the script change kmt new ncl This script is based on the pre existing present day topography kmt file the user may start from a different one as well kmt file provided by the CESM 1 0 2 in the csm inputdata ocn pop2 grid directory the present day land sea mask and region mask are binary files ieee4 The script change kmt new ncl is able to open those files and change only the areas where the new topography is different from present day POP is particularly sensitive to new continental points inserted in the new topography That is why for practical issue when simulating near past climates
40. use_rc1850_c090630 nc Output mksrf_pft_mis6_harvest nc NCL nn fill ncl Input mksrf glacier mis6 111021 nc mksrf_lanwat_mis6 111021 nc mksrf_pft_mis6 harvest 111021 nc mksrf soitex 10level c010119 nc mksrf organic 10level 0 5deg 081112 nc mksrf_fmax 070406 nc mksrf soilcol global c090324 nc mksrf lai global c090506 nc Output mksrf glacier mis6 nn nc mksrf lanwat mis6 nn nc mksrf_pft_mis6 harvest nn nc mksrf_soitex 1Olevel_mis6 nn nc mksrf_organic 10level 0 5deg_mis6 nn nc mksrf fmax mis6 nn nc mksrf_soilcol_mis6 nn nc mksrf_lai_global_mis6 nn nc NCL create_urban ncl Input mksrf urban 3den 0 5x0 5 simyr2000 c090223 v1 nc mksrf pft mis6 harvest nn 111021 nc Output mksrf urban mis6 nc CESM 1 0 2 near past initial conditions user guide prescribing ice sheets files listed in Table 6 To edit the script 0 cp convert mksrf template convert mksrf template myrun 1 edit convert mksrf template myrun and then to compile and execute gt cp convert mksrf template myrun convert mksrf F90 gt gmake gt convert mksrf 4 3 Finalising the new PFTs distribution After creating the new glaciers and ice sheets PFTs the user has to add those modifications to the landunits and the PFTs of pre industrial or present day pre existing default distribution First the crop areas are modified and substituted by the new glaciers PFT computed at the previous step This step is done using the
41. wing document aims at describing this procedure to modify the initial conditions files for the coupled atmosphere land ocean sea ice compset of the CESM 1 0 2 B compset The various scripts presented here have been ported and successfully tested on CMCC IBM Power 6 platform to simulate a glacial maximum However this process is by far non automatic and requires some substantial manual work at each stage of the procedure Finally following this procedure does not provide any guarantees that the simulations will be successful The user may find the scripts on CMCC wiki or directly request them to one of the authors of this User Guide 2 Modelling near past climates Simulating past climates implicates various changes in the Earth s topography Fifty million years Mys ago the continental distribution was completely different and reached its present day config uration about 10 Mys ago Near past climates refers more or less to the last 10 Mys during which only sea level and surface elevation were different due to the alternation of glacial interglacial cycles Figure 2 On the contrary Deep past climate refers to time periods older than 10 Mys more specifically when the continental distribution was totally different than the modern one T T T T T T 100 w ae 100 E Figure 2 Last Glacial Maximum topography from ICE 5G reconstruction Peltier 2004 White areas correspond to the distribution of ice sheets and glaciers at t
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