cfsv2 user manual - Indian Institute of Tropical Meteorology
Contents
1. CDAC Climate Forecast System Vn 2 0 ms Atmospheric Model and MOM4 script for Ocean Model Atmosphere model part of this script runs a global spectral atmosphere model The initial conditions and run parameters are passed in the argument list The Ocean model part runs the Modular Oceanic Model 4 for the number of days specified in the namelist namelist control The script sets up the pre execution environment for the atmospheric oceanic and coupler components and also performs the post execution tasks saving output files appending date suffix to filenames for identification removing intermediate files after the completion of the model run iv jobs Name Description fcst sh This script is the main driver script to run the forecast This script sets the model variables along with variables for MPMD execution The script runs CHGRES optionally before the forecast ocnp sh This script runs the post processor for the ocean model The daily ocean and ice data in NETCDF format is interpolated and written in GRIB1 format post sh This script runs the post processor for the atmosphere model The native model output in binary IEEE GRIB format is written to GRIB1 format v bin Name Description ncpx This command efficiently copies files particularly for NFS pbeg This script runs when parallel jobs begin pend This script runs when parallel jobs end It sets the sequence of execution of jo2. ndate Module to compute verifying date given the forecast hour and the initial date The forecast hour may also be negative and the output verifying date and the initial date are in YYYYMMDDHH format nhour Module to compute forecast hour given the verifying date and the initial date The verifying date and the initial date are in YYYYMMDDHH format Leading zeros are added to make forecast hour at least two digits and a leading minus in the forecast hour signifies that the initial date comes after verifying date 3 2 3 Scripts i util ush Name Description errexit sh This script is to be used when a fatal error or condition has been reached and you want to terminate the job The script puts fail messages in job output file and in the job logfile a fail message is sent to the front end and processing is terminated finddate sh This script looks in either forward or backward in time to generate either a variable containing sequential date time stamps for a period up to a month or just the date time stamp occurring at the end of such a period Time stamp is in the form yyyyddmm Leap years are accounted for postmsg sh This script posts messages to a log file The script assumes that the variable 19 EDAC User s Manual jobid has been exported by the parent shell The variable jobid contains the name of the job and its process id in the form jobname pid startmsg sh This script posts th
3. CDAC User s Manual S No Directory Name Executable Created 15 wgrib cd wgrib 16 ndate fd ndate 17 nhour fd nhour 4 2 2 3 Debugging Instructions The following instructions will help you find out the possible cause of failure of full or part of the installation 1 Open the file log install which is created in build directory as a part of the installation 2 Locate the failed component s section in log install file and find the error 3 After fixing the error you need not install the full model from the beginning again instead you can install only the failed component s 4 3 Running the model The CFSv2 model is programmed to run both in the coupled as well as atmosphere only standalone mode At CDAC the model has been run in both coupled and atmosphere only mode on the IBM V AIX platform On Linux platform the model has been run in coupled mode 4 3 1 Coupled Mode As there is no GUI for the model it needs to be run via command line Before starting the model run perform the following steps to setup the model run Step 1 Place the initial conditions appropriately 1 The atmospheric initial conditions viz sigma and surface files to be placed in SCFSROOT com directory Files accepted by the model are siganl gdas YYYYMMDDHH for sigma file and sfcanl gdas YYYYMMDDHH for surface file 44 CDAC Climate Forecast System Vn 2 0 2 The ocean initial conditions to be placed
4. User s Manual Climate Forecast System Version 2 0 Center for Development of Advanced Computing August 2014 Version Date 10 Aug 15 2014 IN Sch O CDAC User s Manual Climate Forecast System Vn 2 0 CDAC Knowledge Park No 1 Old Madras Road Byappanahalli Bengaluru 560038 Karnataka India Ph 91 80 6611 6400 01 02 03 25244059 25246823 25246826 Fax 91 80 25247724 www cdacb in Revision History 1 0 15 08 2014 User s Manual for Climate Forecast Mohit Ved Ramesh System Vn 2 0 Naidu Contents 1 GENERAL INFORMATION sni 1 TLPREAMBLE iaa 1 1 2 ORGANIZATION OF THE MANUAL cccccccccssscccessssecccssscecccsscecesssseecesasseccesaeeeceesuseccesuseccessuseceestseecessseeceseueseesteeesensas 1 1 3 ACRONYMS AND ABBREVIATIONS ccccccccsssccccssssecccsscceccesscccesssseccesueeccesseececssseccesssseecesuseceesseesessseecesuueseestseeeensas 2 1 4 POINT OF CONTACT ernennen EA E a A a a 2 2 DESCRIBING THE SYSTEM sen ii Ri a 3 2 1 INTRODUCTION TO CFSV2 pa nana aa a aaa aaa a Ma aan aa Sea Kk Eaa a E Aa ea aaa naa Aa EA a Kena aaa aaa O EAE E Ei aan aa kaa 3 2 2 WIRGRADES TO GROW IT nn nn an EEEE E a E EE a ee A EE EEA 7 2 3 CFSV2 RETROSPECTIVE FORECASTS AT NCEP nn rnr aran enak kaka kaa Kaka Kaka KK nannnononnnnnoronnn cnc rannnoninannns 9 3 MODEL SPECIFICATION So cicinciccisonioniicnnnioniocnnoniiccnsionicncianincaniannconnon
5. The CFSv2 model in a nutshell is described in the following table Analysis Resolution 38 km 64 levels Atmosphere model 2008 100 km 64 levels Variable CO AERSW amp LW radiation Prognostic clouds amp cloud condensate Re tuned mountain blocking Convective gravity wave drag Ocean model MOM 4 fully global Y x Y deg Assimilated depth 4737 m Land surface model LSM and 4 level NOAH model assimilation GLDAS driven by observed precipitation See Daily analysis and Prognostic sea ice Radiances assimilated 2008 GSI coupled background Table 2 1 CFSv2 configuration chart 2 2 Upgrades to CFSv1 There have been significant modifications in CFSv1 to build CFSv2 It took seven years for the developers to implement the following aspects in CFSv2 e Introducing a 3 layer interactive global sea ice model as well as a global land data assimilation e Increase in the resolution of the atmospheric forecast model from T62 210 km to T126 100 km CDAC User s Manual e Upgrading the ocean forecast model from the limited area GFDL MOM3 to the global MOMA The horizontal resolution is increased from 0 33 to 0 25 from 10 North to 10 South latitudes Northwards and southwards to the poles the resolution is increased from 1 to 0 5 globally e Upgrading the land surface model from 2 level OSU model to 4 level NOAH land model e Upgrading the data assimilation for the climate forecast model The resolution of the atm
6. 4 2 1 System Requirements The minimum set of specifications required to build the CFSv2 model on a CDAC like Linux system are described here This does not restrict the installation of the model on other hardware software platforms The hardware specifications of the cluster where the model has been installed and tested have been mentioned in table 4 1 Following system software are minimally essential for building the model Libraries e Intel Math Kernel Library MKL and its dependencies e Intel MPI and its dependencies e OpenMP e NetCDF Compilers e Intel FORTRAN and C compilers ifort e icc mpicc mpiifort 38 CDAC Climate Forecast System Vn 2 0 4 2 2 Installation Instructions The CFSv2 build mechanism is fairly simple Three components need to be built for CFSv2 Model Libraries Source modules and Utilities Each of these components follows a two step installation process Configuration and Compilation Building The first step viz configuration is accomplished by running the configuration script This script sets the required paths and generates a makefile for each module using a template makefile and an options file The second step viz building is accomplished by running the build script to create the necessary libraries and the executables The configuration and building is done separately for libraries source modules and utility modules however the process followed for configuration a
7. Alike CFSv1 the CFSv2 also includes a comprehensive set of retrospective runs that are used to calibrate and evaluate the skill of its forecasts These runs are available as 9 months first season and 45 days retrospective forecasts 2 3 1 9 month Retrospective Predictions The retrospective 9 month forecasts have initial conditions of the 0 6 12 and 18Z cycles for every 5th day starting from 1 Jan OZ of every year over the 29 year period i e 1982 2010 This is required to calibrate the operational CPC longer term seasonal predictions ENSO etc There are 292 forecasts for every year for a total of 8468 forecasts This results in an ensemble size of 24 forecasts for each month except November which has 28 forecasts The retrospective forecast calendar Saha et al 2013 outlines the forecasts that are used each calendar month to estimate proper calibration and skill estimates in such a way to mimic CPC operations Smoothed calibration climatologies have been prepared from the forecast monthly means and time series of selected variables and is available for download together with selected data from the retrospective forecasts from the NCDC web servers Saha et al 2013 2 3 2 First Season and 45 day Retrospective Forecasts These retrospective forecasts have initial conditions from every cycle 0 6 12 and 18Z of every day over the 12 year period from Jan 1999 Dec 2010 Thus there are approximately 365 4 forecasts per year for a to
8. These verification datasets are also provided alongwith the portable CFS model software system 47 References S Saha S Nadiga C Thiaw J Wang W Wang Q Zhang H M van den Dool H L Pan S Moorthi D Behringer D Stokes G White S Lord W Ebisuzaki P Peng P Xie The NCEP Climate Forecast System Journal of Climate 2006 Vol 19 No 15 pages 3483 3517 Kanamitsu Masao Wesley Ebisuzaki Jack Woollen Shi Keng Yang J J Hnilo M Fiorino G L Potter 2002 NCEP DOE AMIP II Reanalysis R 2 Bull Amer Meteor Soc 83 1631 1643 Behringer D W 2007 The Global Ocean Data Assimilation System at NCEP 11 Symposium on Integrated Observing and Assimilation Systems for Atmosphere Oceans and Land Surface AMS 87th Annual Meeting San Antonio Texas 12pp Moorthi S H L Pan and P Caplan 2001 Changes to the 2001 NCEP operational MRF AVN global analysis forecast system NWS Technical Procedures Bulletin 484 pp14 Mlawer E J S J Taubman P D Brown M J lacono and S A Clough 1997 Radiative transfer for inhomogeneous atmosphere RRTM a validated correlated K model for the longwave J Geophys Res 102 D14 16 663 16 6832 Ek M B K E Mitchell Y Lin E Rogers P Grunmann V Koren G Gayno and J D Tarplay 2003 Implementation of the Noah land use model advances in the NCEP operational mesoscale Eta model J Geophys Res 108 8851 doi 10 1029 20
9. psub post1 psub ocnp1 28 CDAC Climate Forecast System Vn 2 0 3 3 2 Call flow of the post processing program The post processor follows the same pattern for initialization as followed by the model forecast program Post processing scripts are called after initialization which in turn call the respective executable files 3 3 2 1 Post processor for the Atmosphere psub post1 reconcile sh nhour pene post mdl sh global sighdr global nceppost sh 29 EDAC User s Manual global_sighdr global_ dica sh E global_chgres cfs_overparm_ grib copygb cfs_overparm_ grib global_anomcat sh 30 CDAC Climate Forecast System Vn 2 0 global_sighdr global_nceppost sh global_chgres sh global_chgres cfs_overparm_grib copygb nt cfs_overparm_grib global anomcat sh 31 CDAC User s Manual global_nceppost sh global_sighdr global_chgres sh E global_chgres 32 Climate Forecast System Vn 2 0 33 CDAC User s Manual psub ocnp1 3 3 2 2 Post processor for the Ocean psub ocnp1 para_config reconcile sh 34 CDAC Climate Forecast System Vn 2 0 35 4 Installation and Setup 4 1 About CTSF GG BLR As part of the Garuda Grid Computing Initiative 4TF Linux cluster was setup at CTSF which provides resources for Grid applications The
10. without first reading through all the preceding data e Extendible It means that data can be appended to a NetCDF data set without copying it or redefining its structure NetCDF files are used for creating oceanic output files for platform independent usability sfcio This library provides an application Program Interface for performing I O on the surface restart file of the global spectral model Functions include opening reading writing and closing as well as allocating and de allocating data buffers used in the transfers The I O performed here is sequential The transfers are limited to header records or data records sigio This module provides an Application Program Interface for performing I O on the sigma restart file of the global spectral model Functions include opening reading writing and closing as well as allocating and de allocating data buffers used in the transfers The I O performed here is sequential and random The transfers are limited to header records data records surface data records or specific levels of upper air data records sp Analyzes spectral coefficients from Fourier coefficients for a latitude pair This library spectrally truncates vector fields on a global cylindrical grid returning the fields to a possibly different global cylindrical grid The wave space can be either triangular or rhomboidal Either grid space can be an equally spaced grid or a Gaussian grid It performs multip
11. Passing Interface constructs The model is used for long range and seasonal forecasting 1 2 Organization ofthe manual Section 1 General information with regards to the manual abbreviations used in the manual and the point of contact for using the manual and the related product Section 2 Brief specifications of the model physics including components of the model upgrades to the previous version and the design of Retrospective forecasts carried out and the operational configuration at NCEP Section 3 A brief description of the directories included in the package a description of the functionalities of the modules and scripts along with the code flow of the forecast cycle of the model and the post processing Section 4 General information about the Linux cluster at CDAC installation procedure and guidelines for running the model in coupled mode and a description of the outputs generated by the model and the post processor program This is one of the reference platform on which the model is tested successfully EDAC User s Manual 1 3 Acronyms and Abbreviations AMIP CDAC CDAS CFS CPC GARUDA GFDL GFS GODAS GPCP ISMR MOM MRF NCAR NCEP NOAA SFM SST Atmospheric Model Inter comparison Project Centre for Development of Advanced Computing Climate Data Assimilation System Climate Forecast System Climate Prediction Center India s first national grid initiative Geophysical Fluid Dynamics La
12. Retrospective Forecasts Time Series of Daily Data in the EMC NCEP CFS public server www cfs ncep noaa gov daily cfs data doc Catherine Thiaw and Suranjana Saha 2007 CFS Retrospective Forecasts Time Series of Monthly Means Data in the EMC NCEP CFS public server www cfs ncep noaa gov monthly cfs data doc The Global Forecast Model GFS Global Spectral Model GSM EMC NCEP GFS Public server http www emc ncep noaa gov GFS doc ph Network Common Data Form library http www unidata ucar edu software netcdf docs faq html whatisit Earth System Modeling Framework ESMF http www earthsystemmodeling org about us index shtml 50
13. be appended to a file a option If grib2 is specified as then the output GRIB file is written to standard output grbindex It creates an index file from a GRIB file The index file serves as a table of contents for the GRIB file enabling quick access to the data The GRIB file must be unblocked but there can be a gap before the first GRIB message of at most 32000 bytes and gaps between messages of at most 4000 bytes The two file names are retrieved from the command line arguments The first argument is the name of the input GRIB file The second argument is the name of the output index file Currently only version 1 of GRIB can be read wgrib The command wgrib both inventories and decodes GRIB 1 files There are three types of inventories regular short and verbose which can be viewed as a 18 CDAC Climate Forecast System Vn 2 0 human readable index file The inventories can be manipulated to select the records to decode The output formats of wgrib include text binary system dependent big endian IEEE and GRIB In addition the program can produce a non inventory description of the GRIB records Information includes range of values grid type etc The program can be compiled to either use the NCEP operational GRIB tables or the NCEP NCAR Reanalysis GRIB table as the default table in cases of ambiguity The program does not handle spectral files nor files with complex packing
14. in SCFSROOT com directory as a tar file File accepted by the model is ocnanl gdas YYYYMMDDHH tar 3 The time dependent and angle dependent satellite bias correction input files also need to be placed in the SCFSROOT com directory These files are named biascr gdas YYYYMMDDHH and satang gdas YYYYMMDDHH respectively Step 2 Next verify the values set in section 1 in the script submit sh located in the SCFSROOT exp directory The HOMEDIR is set to the path provided during configuration The configuration file is specified by the CONFIG variable If running with another set of input conditions cdate should be changed accordingly Step 3 The next steps towards running the model program are a Setting the length of the forecast and b The distribution of processors to run the three model components viz Atmosphere Ocean and Coupler These can be done in section 1 in configuration file para_config_cfs located at SCFSROOT exp This section contains the following variables e run length Length of the run in hours e n_procs Total number of processors e n_procs o Number of processors for ocean e out freq Output frequency in hours a The forecast length of the model is described in terms of hours of forecast The model takes this input from the variable run_length Set this variable to appropriate value to specify the length of forecast b To change the number of processors to run the individual model components per
15. land atmosphere ocean model to provide land surface prediction of surface fluxes surface boundary conditions and in the Global Land Data Assimilation System GLDAS to provide the land surface analysis and evolving land states Figure 2 1 The main components of the Climate Forecast System Vn 2 The CFS model which runs on multiple processes with message passing tools uses a parallel programming model called MPMD The three programs in the CFS the atmospheric model GFS the ocean model MOM4 and the coupler each of which has its own data flow run CDAC User s Manual independently but they exchange data as follows the GFS runs on the atmospheric time step Aa 3 min MOM4 runs on a fast sea ice time step Ai also 3 min for the sea ice model and a slow ocean time step Ao 30 min for both the ocean model and slow sea ice time step while the coupler runs on a time step Ac where Ac max Aa Ai At every coupler time step Ac the coupler will receive data from both the GFS and MOM4 sea ice model and will send the needed data back to them respectively At every ocean time step in addition to the data exchanged between GFS and sea ice the coupler will also receive accumulated variables fluxes from the GFS and send them to the ocean model while receiving data from the ocean and sea ice model and sending them back to the GFS se A Figure 2 2 GFS Sealce MOM4 Coupler CDAC Climate Forecast System Vn 2 0
16. nonlocal boundary layer parameterization Reviews of Geophysics 32 363 403 Gent P R and J C McWilliams 1990 Isopycnal mixing in ocean circulation models Journal of Physical Oceanography 20 150 155 Griffies S M A Gnanadesikan R C Pacanowski V Larichev J K Dukowicz and R D Smith 1998 Isoneutral diffusion in a z coordinate ocean model Journal of Physical Oceanography 28 805 830 Griffies S M and R W Hallberg 2000 Biharmonic friction with a Smagorinsky viscosity for use in large scale eddy permitting ocean models Monthly Weather Review 128 2935 2946 Hunke E C J K Dukowicz 1997 An Elastic Viscous Plastic Model for Sea Ice Dynamics J Phys Oceanogr 27 1849 1867 Winton M 2000 A reformulated three layer sea ice model J Atmos Oceanic Technol 17 525 531 Mitchell K et al 2005 NCEP implements major upgrade to its medium range global forecast system including land surface component GEWEX newsletter May 2005 Saha S et al 2013 The NCEP climate forecast system version 2 J climate Available from http cfs ncep noaa gov cfsv2 info CFSv2 paper pdf 49 CDAC User s Manual Janakiraman S M Ved R N Laveti P Yadav and S Gadgil 2011 Prediction of the Indian summer monsoon rainfall using a state of the art coupled ocean atmosphere model Current Science 100 354 362 Catherine Thiaw and Suranjana Saha 2006 CFS
17. parameter id read in Change is made to that id only if the replacement is positive The non GRIB information in the input GRIB file will be lost if it is present An output line will be written for each GRIB message 8 Dir cfs_psichi fd Exec cfs_genpsiandchi This module reads wind on grid points transform them back to spectral space and then computes Stream function Psi velocity potential Chi vorticity and divergence 9 Dir global_sighdr fd Exec global_sighdr This module extracts and prints the information from the sigma header of a sigma file It can print the parameters such as type of the file filetype truncation number jcap number of vertical coordinates nvcoord Running sfchdr with no additional arguments other than the input file as in the last example allows for keyboard input of multiple variables one at a time until the program is interrupted eg via CTRL c Enter without the quotes as standard input and then all the possible input values will be printed 10 Dir cfs_tripo2reg fd Exec cfs_tripo2reg This module reads daily ocean and ice data on tripolar grid and interpolates the data onto regular lat lon grid 11 Dir cfs_separ3 fd Exec cfs_separ3 This module separates the output log of the parallel coupled run into three independent files one each for atmosphere ocean and coupler 17 CDAC User s Manual 3 2 2 Utilities Name Despcription anomgb This mod
18. surface fluxes cloud cover etc on 384 x 190 Gaussian T126 grid 3 Ocean data temperature salinity currents at 40 different depths and sea level height on 1 x 1 and 0 5 x 0 5 grid 4 Isentropic level data temperature wind humidity etc at 16 isentropic levels on a 1 x 1 grid 46 CDAC Climate Forecast System Vn 2 0 The model output directory is SCFSROOT com and the corresponding files are Sr No File File naming convention File type Model Output 1 flx fIx lt R gt lt HH gt gdas lt IC DATE gt GRIB 2 sigf sigf lt HH gt gdas lt IC DATE gt Binary 3 sfcf sfcf lt HH gt gdas lt IC DATE gt Binary 4 ice ice_YYYY_MM_DD_HH gdas lt IC DATE gt nc NetCDF 5 ocn ocn_YYYY_MM_DD_HH gdas lt IC DATE gt nc NetCDF Post Output 6 pgb pgb lt R gt lt HH gt gdas lt IC DATE gt GRIB 7 ocn ocn lt R gt lt HH gt gdas lt IC DATE gt GRIB 8 ipv ipv lt R gt lt HH gt gdas lt IC DATE gt GRIB where R one character signifying the resolution of the output file which can be any of the following f model resolution Gaussian Grid low resolution 1 x 1 h high resolution 0 5 x 0 5 HH two digit forecast hour IC DATE Initial condition date in the format YYYYMMDDHH 4 5 Verification Data CFSv2 has been implemented on CDAC s high performance Linux system GG BLR The system has been run for short range and medium range simulations
19. 02JD003296 Wu X K S Moorthi K Okomoto and H L Pan 2005 Sea ice impacts on GFS forecasts at high latitudes Proceedings of the 85 AMS Annual Meeting 8 Conference on Polar Meteorology and Oceanography San Diego CA Alpert J C 2004 Subgrid scale Mountain blocking at NCEP Proc 20 Conf on Weather and Forecasting Seattle WA Lott F and M J Miller 1997 A new subgrid scale orographic drag parameterization ts performance and testing Quart J Roy Meteor Soc 123 101 127 CDAC Climate Forecast System Vn 2 0 Collins N G Theurich C DeLuca M Suarez A Traynaov V Balaji P Li W Yang C Hill and A da Silva 2005 Design and implementation of components of Earth System modeling Framework The International Journal of High Performance Computing Applications 19 3 Summer 2005 pp 355 356 McCormack J P S D Eckermann D E Siskind and T McGee 2006 CHEM2D OPP A new linearized gas phase photochemistry parameterization for high altitude NWP and climate models Atmos Chem Phys 6 4943 4972 Saha Suranjana and Coauthors 2010 The NCEP Climate Forecast System Reanalysis Bull Amer Meteor Soc 91 1015 1057 Murray R J 1996 Explicit generation of orthogonal grids for ocean models Journal of Computational Physics 126 251 273 Large W G J C McWilliams and S C Doney 1994 Oceanic vertical mixing A review and a model with a
20. 64 and the MOM3 ocean forecast model from GFDL CFSv2 has improvements in all four components mentioned above namely the two forecast models and the two data assimilation systems CFSv2 also has a few novelties an upgraded four level soil model an interactive three layer sea ice model and prescribed historical i e rising CO concentrations But above all CFSv2 was designed to improve consistency between the model states and the initial states produced by the data assimilation system The atmospheric component of CFSv2 is the NCEP atmospheric GFS model Moorthi et al 2001 with significant improvements GFS is a global spectral model A sample of improvements is listed here For complete information on improvements refer to Saha et al 2012 The atmospheric model has a spectral triangular truncation of 126 waves T126 in the horizontal equivalent to nearly a 100 Km grid resolution and a finite differencing in the vertical with 64 sigma pressure hybrid layers The vertical coordinate is the same as that in the operational CDAS Additional improvements to the GFS Atmospheric Model AM include CDAC User s Manual fast and accurate LW radiation parameterization based on the RRTM developed at AER Mlawer et al 1997 It is also coupled to a four layer NOAH Land Surface Model Ek et al 2003 and a two layer Sea Ice Model Wu et al 2005 In addition to gravity wave drag the model now includes a parameterization of mountain blockin
21. GG BLR cluster consists of 40 Nos HP Proliant DL160 compute nodes and 1 No of HP Proliant DL360 head node Each of the compute nodes has Intel Xeon 8 core X5460 processors 3 16GHz and 16 GB memory It has a total of 320 processors and 640 GB of memory and the nodes are connected by Infiniband interconnect GG BLR has a theoretical peak of 4044 80 Gflops secs 4TF Table 4 1 describes the hardware and software configuration of the GG BLR cluster Head node File server Processor Memory Internal Storage Operating System Compute Node Processor Memory Internal Storage Operating System Networks Primary Backup Management Table 4 1 Hardware and Software configuration of GG BLR GG BLR Cluster 2 X Quad core Xeon 3 16 Ghz 24 GB 2 4 146 G SAS HDD Rocks 5 0 on RHEL 5 1 x86_64 2 X Quad core Xeon 3 16 Ghz 16 GB 2 X 250 G SATA HDD Rocks 5 0 on RHEL 5 1 x86_64 Infiniband 20 Gbps Full Duplex Gigabit Ethernet 1 Gbps Full Duplex 10 100 Mbps Fast Ethernet CDAC Climate Forecast System Vn 2 0 External Storage 10 TeraBytes SAS St A i i 24 TeraBytes SATA Operating System RHEL 5 1 x86_64 on Rocks 5 0 Compilers and Related Tools Intel Compiler Suite 11 0 Intel MKL MVAPICH2 MPICH2 OPENMPI Local Resource Manager Torque 2 3 The GG BLR cluster is also accessible to users from remote locations via the GARUDA Grid infrastructure 4 2 Model Installation The Climate Forecast System has
22. b steps perr This script runs when parallel jobs fail 21 CDAC User s Manual pcne This script counts non existent files plog This job logs parallel jobs pmkr This script makes the rlist the list of data flow for the experiment pcon This script searches the input rlist for patterns and returns the assigned value psub This script checks the pre requisites for the job steps and runs parallel jobs vi exp Name Description para_config This is the configuration file for CFS or GFS It sets the options for the model components Various model configuration options such as coupled stand alone case post options paths for source scripts output directories utilities computing nodes output resolution etc can be set here submit sh This is the start script i e the first script to be executed It submits the forecast job pbs submit PBS script to submit the job on Linux cluster create_tar sh Script to create a tar bundle of model output 3 2 4 Libraries Name Description bacio This library is responsible for performing byte addressable input and output operations It contains the FORTRAN callable routines to read and write character bacio and numeric banio data byte address ably It includes the byte addressable read and write operations on the file descriptor that is provided crtm Community Radiative Transfer Model This library co
23. been successfully ported on the HPC facility available at C DAC Bangalore i e GG BLR Since the code is architecture bound hence some modifications in the code and the installation options specific to the platform may be needed for successful installation The CFS was ported on GG BLR with MPP configuration Since the model has been specifically designed for the IBM AIX platform the source code model scripts and the compilation options were significantly changed to accommodate the change in platform While a few modules supplied with the bundle were found to be incomplete they were replaced with the modules available at the NCEP website A few missing files were separately downloaded from the website and placed at the respective locations Installation of CFS on a hardware similar to 37 CDAC User s Manual GG BLR should be straight forward without much difficulties except the fact that care must be taken when using different versions of compilers and the supporting libraries The process of building and running the Climate Forecast System on a Linux platform is performed in the following stages e Building the required libraries for the model e Building the source and utility modules to create the corresponding model executables e Configuring the model for the run w r t run length processor configuration output frequencies etc e Submitting the model job to cluster system using the cluster job submission process
24. boratory Global Forecast Model Global Ocean Data Assimilation System Global Precipitation Climatology Project All India Summer Monsoon Rainfall Modular Ocean Model Medium Range Forecast National Center for Atmospheric Research National Centers for Environmental Prediction National Oceanic and Atmospheric Administration Seasonal Forecast Model Sea Surface Temperature 1 4 Point of Contact All queries related to the CFS model can be sent to spim cdac in or can also be mailed at the following address c o Seasonal Prediction of Indian Monsoon SPIM Team C DAC Knowledge Park No 1 Old Madras Road Byappanahalli Bengaluru 560038 Karnataka India 2 Describing the System 2 1 Introduction to CFSv2 The first release of CFS retroactively called CFSv1 was implemented into operations at NCEP in August 2004 and was the first quasi global fully coupled atmosphere ocean land model used at NCEP for seasonal prediction Saha et al 2006 CFSv1 was developed from four independently designed pieces of technology namely the R2 NCEP DOE Global Reanalysis Kanamitsu et al 2002 which provided the atmospheric and land surface initial conditions a global ocean data assimilation system GODAS operational at NCEP in 2003 Behringer 2007 which provided the ocean initial states NCEP s Global Forecast System GFS operational in 2003 which was the atmospheric model run at a lower resolution of T62L
25. ce and Utility modules separately If required How to build only libraries Enter 1 as your choice Instead of building all the libraries user can also build a set of libraries if required The installer asks the choice from the user to build all the libraries or one or more particular libraries Select the library which you want to install 1 or 2 1 All 2 Select from list Press 1 to build all the libraries Press 2 to build a set of libraries If you press 2 then you must give a list of libraries which need to be built Then follow the instructions given by the installer After the successful installation of libraries the libraries will be placed in the directory SCFSROOT Iib and the module files of the libraries will be placed in SCFSROOT incmod How to build only source modules Before starting the installation of source modules user should make sure that all the dependency libraries are built successfully Enter 2 as your choice The installer asks the choice from the user to build all the modules or one or more particular modules from the list Select the source module which you want to install 1 or 2 1 All 2 Select from the list Press 1 to build all the source modules Press 2 to build a set of source modules If you press 2 then you must give a list of source modules which need to be built 41 EDAC User s Manual V After the successful installati
26. d by the post processor are Surface related fields Sounding and Cloud related fields Fixed fields Radiance and Brightness fields Sea Level Pressure and other miscellaneous fields viz tropopause level fields FD Upper Winds Wind and Temperature Aloft Forecast level fields Freezing level height and Relative Humidity Boundary layer fields and LFM Limited area Fine Mesh Model and NGM Nested Grid Model look alike fields 3 Dir cfs_ao_coupler fd Exec cfs_mlc_coupler This module co ordinates the execution of the ATMOS and OCEAN models and transmits data between them The data transmission includes receiving SST from OCEAN and sending to ATMOS and receiving FLUX from ATMOS and sending to OCEAN 4 Dir cfs_cdas_atmos_fcst fd Exec cfs_cdas_atmos_fcst This module is the atmospheric component GFS of CFSv2 with triangular truncation T126 0 937 for horizontal resolution and 64 hybrid sigma 3 pressure levels in the vertical finite difference method is used in the solution of the equations This module will be coupled with Ocean Model using a coupler module The atmosphere model AM the Ocean Model OM and the coupler will be run simultaneously in MPMD fashion This module can run in coupled mode as well as stand alone mode The coupling frequency is flexible up to the Ocean Model time step 5 Dir cfs_mppnccombine cd Exec cfs_mppnccombine This module joins together NetCDF data files representing a decomposed domain into a un
27. e program started message to the log file when any program starts ii ush Name Description global_anomcat sh This script computes the height anomalies at 1000 and 500 mb and the five wave height anomaly at 500 mb and concatenates them to a pressure GRIB file global_chgres sh This script changes the resolution of the global restart files namely the sigma file or the surface file or both The resolution of the output files is given in the argument list or as imported environment variables The resolution of the input files are taken from the header records in the respective files Resolution is given as spectral truncation number of levels number of longitudes and number of latitudes global_nceppost sh This script reads a single global GFS IO file and optionally a global flux file and creates a global pressure GRIB file The resolution and generating code of the output GRIB file can also be set in the argument list reconcile sh This script sets the final environment for the forecast after the basic environment has been set in para_config file It sets required but unset variables to default values With this version forecasts can be made using two model resolutions post mdl sh This script runs the post processor for the forecast iii scripts Name Description excfs_cdas_fcst sh s This is a MPMD coupled script to run CFS using the GFS script for 20
28. e tree and then go to the directory build S cd SCFSROOT build The build directory contains installation script and three options files for model libraries source modules and the utility modules 4 In order to change the compiler and or its options open the corresponding options file and make the necessary changes Make sure the changes made are consistent for all model components else it may lead to run time incompatibility errors Prior to the installation keep a note of full paths of CFSROOT NetCDF include and library directories and MKL directory Install CFSv2 software system by running the installer S install sh a The installer starts by asking the user to enter the full paths of CFSROOT NetCDF include and library directories and MKL directory b Next the user is asked to select the installation choice out of the following installation choices User can install each component separately or the entire model in a single step For the first time the user may select option 4 for complete model installation Other options may be selected in subsequent installations as per the requirement 1 Install Libraries To install all the libraries 2 Install Source modules To install all the source modules 3 Install Utility modules To install all the utility modules 4 Install All Entire Model To install the entire model 40 CDAC Climate Forecast System Vn 2 0 A Install Libraries Sour
29. form the following steps e Set variable n_procs equal to the total number of processors intended for model run 45 EDAC User s Manual Step 4 Set the number of processors for the Ocean model in variable n_procs_o The number of processors for Coupler generally 1 and Atmospheric component is computed by the script itself For example For the runs made at CDAC for total processors n_procs as 80 n_procs_o was set to 31 Hence number of processors for atmosphere becomes 48 Lastly change the environment variable corresponding to the processors in the PBS script If you are using PBS on your cluster namely SCFSROOT exp pbs submit as PBS I nodes 10 ppn 8 Finally the model run can be submitted to the PBS job scheduler by the PBS script located at SCFSROOT exp pbs submit by issuing the following command Sqsub pbs submit The model output and error log can be checked in the cfsv2 oSjobid and cfsv2 eSjobid files respectively while the model part being run can be checked in SCFSROOT exp prcfsv2 runlog Intermediate Output logs In directory com YYYYMMDDHHgdasfcst1 out gt out mpiexec lt FH_CYCL gt error gt err mpiexec lt FH_CYCL gt 4 4 Model Output The default configuration of the model outputs 1 Isobaric level data winds temperatures heights etc at 37 pressure levels in the atmosphere on a 1 x 1 grid 2 Surface data 2 m temperature precipitation snow 10 m wind
30. g Alpert 2004 following the subgrid scale orographic drag parameterization by Lott and Miller 1997 The GFS AM now takes advantage of the ESMF based modern computer algorithms Collins et al 2005 An update of the ozone production and destruction terms is done using the monthly mean data provided by the NRL McCormack et al 2006 The ocean and sea ice models are identical to those used in CFSR Saha et al 2010 The oceanic component is the MOM version 4p0d which is a finite difference version of the ocean primitive equations configured under the Boussinesq and hydrostatic approximations The model uses the tri polar grid developed by Murray 1996 Northward of 65 N it uses a rotated bipolar grid that places two poles over land thus eliminating the singularity in the northern ocean while southward of 65 N it uses a regular latitude x longitude grid The horizontal layout is a staggered Arakawa B grid and geometric height is in the vertical The ocean surface boundary is computed as an explicit free surface The zonal resolution is 1 2 The meridional resolution is 1 4 between 10 S and 10 N gradually increasing to 1 2 poleward of 30 S and 30 N There are 40 layers in the vertical with 27 layers in the upper 400 m and the bottom depth is approximately 4 5 km The vertical resolution is 10 m from the surface to the 240 m depth gradually increasing to about 511 m in the bottom layer Vertical mixing follows the nonlocal K profi
31. ified NetCDF file It was originally designed to be used as a post processor for the parallel I O programming interface mpp io mod If the user is running the source code on one processor the domain is not decomposed and there is only one data file mppnccombine requires decomposed dimensions in each file to have a domain_decomposition attribute This attribute contains four integer values starting value of the entire non decomposed dimension range usually 1 ending value of the entire non decomposed dimension range starting value of the current chunk s dimension range and ending value of the current chunk s 15 CDAC User s Manual dimension range mppnccombine also requires each file to have a NumFilesinSet global attribute which contains a single integer value representing the total number of chunks i e files to combine 6 Dir cfs_ocean_mom4ice fd Exec cfs_ocean_mom4ice The Modular Ocean Model MOM is a numerical representation of the ocean s hydrostatic primitive equations It is designed primarily as a tool for studying the global ocean climate system but with recent enhanced capabilities for regional and coastal applications As with all previous versions of MOM MOM4 discretizes the ocean s hydrostatic primitive equations on a fixed Eulerian grid with the Arakawa B grid defining the horizontal arrangement of model fields That is the grid cells live on a lattice fixed in space time Given that MOM4 remains a
32. lag of a few days since the CFSv2 initial conditions are made completely in real time This makes it possible to use them for the sub seasonal week1 week6 forecasts Operational real time data may be downloaded from the official site There are 4 control runs per day from the 0 6 12 and 18 UTC cycles of the CFS real time data assimilation system out to 9 months In addition to the control run of 9 months at the O UTC cycle there are 3 additional runs out to one season In addition to the control run of 9 months at the 6 12 and 18 UTC cycles there are 3 additional runs out to 45 days There are a total of 16 CFS runs every day of which 4 runs go out to 9 months 3 runs go out to 1 season and 9 runs go out to 45 days 10 CDAC Climate Forecast System Vn 2 0 O UTC 6 UTC 12 UTC 18 UTC gt 9 month run 4 gt 1 season run 3 gt 45 day run 9 Figure 2 4 CFSv2 Operational Forecasts The CFSv2 retrospective dataset can be obtained from the official site of CFS 11 3 Model Specifications 3 1 Directory Tree CFSv2 suite has different directories each intended for a special purpose The com directory created at run time is the working directory where the model runs and dumps the output Following is the directory tree of the model suite cfsv2 Main directory for the model bin build exec exp fix init jobs libs These scripts control the flow of an experiment This directory con
33. le Fast Fourier Transforms between complex amplitudes in Fourier space and real values in cyclic physical space It is used for performing various operations in spectral space w3 This library is used to unpack amp read GRIB files and also pack amp write GRIB files The several modules in this library are used for identifying the size of various sections of the GRIB file and reading the appropriate number of bytes It also performs the conversion from ASCII to EBCDIC or from EBCDIC to ASCII by character 25 CDAC User s Manual 3 3 Call flow of the model The model enters the initialization phase before entering into to the forecast phase All model executables are called in the respective shell scripts which first initialize the global variables required for the model run These variables are used throughout the model code Certain variables pertaining to machine path can be changed as per the user convention This is explained later in section 4 3 3 3 1 Call flow of the forecast program Following tree describes the flow of code of the CFS model para_config_cfs reconcile sh para_config_cfs global_sighdr 26 Climate Forecast System Vn 2 0 global chgres sh global chgres excfs cdas fcst sh sms global_sighdr cfs mlc coupler cfs ocean momdice cfs cdas atmos fcst 27 CDAC User s Manual cfs mppnccombine ncpx
34. le parameterization of Large et al 1994 The horizontal mixing of tracers uses the iso neutral method developed by Gent and McWilliams 1990 Griffies et al 1998 The horizontal mixing of momentum uses the nonlinear scheme of Smagorinsky Griffies and Halberg 2000 The configuration for the MOMA4pOd is similar to the one used for MOM version 3 with CFSv1 Saha et al 2006 but the resolution has been approximately doubled and the MOM4p0d is fully global with an Arctic Ocean and an interactive ice model whereas MOM3 is truncated at 64 N and 74 S The sea ice model is from the GFDL Sea Ice Simulator with some modifications Its model grid is identical to the ocean model grid there are three layers for the sea ice model including two CDAC Climate Forecast System Vn 2 0 equal layers of sea ice and one layer of snow In each ice grid there are five categories of possible sea ice thicknesses 0 0 1 0 1 0 3 0 3 0 7 0 7 1 1 m and the category greater than 1 1 m Sea ice dynamics are based on Hunke and Dukowicz 1997 using the elastic viscous plastic technique to calculate ice internal stress Ice thermodynamics are based on Winton 2000 The LSM used in CFSv2 is the NOAH Land Surface Model LSM Ek et al 2003 which was first implemented in the GFS for operational medium range weather forecasts Mitchell et al 2005 and then in the CFSR Saha et al 2010 Within CFSv2 NOAH LSM is employed in both the coupled
35. ly compressible non hydrostatic model with a hydrostatic option The terrain following hybrid pressure sigma vertical coordinate is used The grid staggering is the Arakawa E grid The same time step is used for all terms Time stepping used are Horizontally propagating fast waves Forward backward scheme Vertically propagating sound waves Implicit scheme Forward second order Smagorinsky type horizontal diffusion is used And for the vertical diffusion free atmosphere turbulence above surface layer is used netcdf NetCDF network Common Data Form is a set of interfaces for array oriented data access and a freely distributed collection of data access libraries for C Fortran C Java and other languages The netCDF libraries support a machine independent format for representing scientific data Together the interfaces libraries and format support the creation access and sharing of scientific data NetCDF files are self describing network transparent directly accessible and extendible e Self describing It means that a NetCDF file includes information about the data it contains e Network transparent It means that a NetCDF file is represented in a form that can be accessed by computers with different ways of storing integers characters and floating point numbers 24 CDAC Climate Forecast System Vn 2 0 e Direct access It means that a small subset of a large data set may be accessed efficiently
36. n conservative re mapping spectral and other functional transforms ESMF also includes toolkits for building components and applications such as regridding software calendar management logging and error handling and parallel communications gfsio This library takes model output in Gaussian native grid and writes them out in GRIB format The general interpolation library ip contains FORTRAN subprograms to be used for interpolating between almost any grids used at NCEP There are currently five interpolation methods available in the library They are respectively bi linear bi cubic neighbor budget and spectral interpolation methods Generally only regular grids can be interpolated in this library 23 CDAC User s Manual landsfcutil This library interpolates data to the model grid by taking the nearest neighbor or area average of the source data and interpolates data to the model grid by bi linear interpolation Contains collection of routines that go from lat lon to x y space on various grids and collection of routines that perform soil land related calculations such as roughness length soil type specific parameters albedo based on snow water equivalent snow free albedo maximum snow albedo liquid portion of total soil moisture calculate super cooled soil moisture and re scale total soil moisture for a change in soil type nam_nmm WRF NMM V2 1 fcst real The WRF NMM model is a ful
37. n section 4 3 42 CDAC Climate Forecast System Vn 2 0 Note If you choose to install the full model the installer first installs all the libraries After all the libraries are successfully installed it installs the source modules And at last it installs the utility modules If it fails to install any of the libraries it continues the installation of rest of the libraries however it aborts without installing source modules and utility modules If the installation of any of the source modules fails then it continues with the rest of the source modules and aborts without installing utility modules The table below lists the source directories of the model parts and the respective executable files created by each part after successful compilation Table 4 2 Model source directories and executable files S No Directory Name Executable Created sorc 1 cfs ao coupler fd cfs mlc coupler 2 cfs atmos fcst fd cfs cdas atmos fcst 3 cfs mppnccombine cd cfs mppnccombine 4 cfs ocean momdice fd cfs ocean momdice 5 cfs overparm grib fd cfs overparm grib 6 cfs_psichi fd cfs_genpsiandchi 7 cfs_separ3 fd cfs_separ3 8 cfs_tripo2reg fd cfs_tripo2reg 9 global_chgres fd global_chgres 10 global sighdr fd global sighdr 11 ncep post new fd ncep post util sorc 12 anomgb fd anomgb 13 copygb fd copygb 14 grbindex fd grbindex 43
38. na ando nenn nennen rennen nn anna ciaci n 12 SL DIRECTORY TRES date essen 12 3 2 FUNCTIONALITY OF MODEL COMPONENTS AND SCRIPTS ccccccccssescccesssccceestscccecssecceseseceesseecesssseccesseueceessssesessnaas 13 3 3 CALL FLOW OF THEIMOBEL eiii 26 4 INSTALLATION AND SETUP ji nini ni didi ia AA iii didnt 36 ALABOUTCISH GGBER nn dn AA na Dn ine ann Ma AAA ii 36 4 2 INSTALLATION ON GG BLR CLUSTER ccccceceececcecesecceceecseuseceeseesuseeceseeceseuceseuseeeeseueuseeceeeeceeuceeeuseess 37 4 3 RUNNING THE MODEL cd 44 AAN NIODELOUTPUTE ee a iaa SAR A A a eigene 46 AS VERIFICATION DATA ia an ns ae se rennen nasser 47 REFERENCES ccccssssssssscceeecccccccccssscceeeeccccccccssscceeeeecccccccssseceeeseccocccccsseceesseseoncccssseeesseseooccccseseeeeeees 48 1 General Information 1 1 Preamble This User s Manual describes the Climate Forecast System Version 2 0 CFSv2 a fully coupled ocean land atmosphere dynamical seasonal prediction system that became operational at NCEP in March 2011 CFSv2 is the successor of the earlier version of the model named CFSv1 which became operational in August 2004 This version has upgrades to nearly all aspects of the data assimilation and forecast model components of the system The model uses the shell environment for operation and does not come with any GUI The model has been programmed using FORTRAN 77 with batch input output routines written in C language The code also makes use of Message
39. nd building is the same for all the three components To simplify the installation process of CFSv2 a single installation script installer to perform the two step installation of all the components is provided with the CFSv2 suite The step wise installation procedures quick as well as detailed along with debugging tips are given below 4 2 2 1 Quick Installation 1 Unzip and untar the CFSv2 zipped tar file and go to build directory present in CFSv2 S cd SCFSROOT build CFSROOT is the top directory of CFSv2 software 2 In order to change the compiler and or its options open the corresponding options file and make the necessary changes For example to change the compiler compiler options of libraries open the file options lib and make the necessary changes 3 Prior to the installation keep note of the full paths of CFSROOT NetCDF include and library directories and MKL directory 4 Install CFSv2 software system by running the installer S install sh 5 After the successful installation user can run CFSv2 using the run instructions described in section 4 3 39 CDAC User s Manual 4 2 2 2 Detailed Installation 1 Get the CFSv2 zipped tar file Unzip and untar this file to your system We call the directory where the model is untarred as CFSROOT Check whether the system requirements mentioned in section 4 2 1 are met by the target machine Descend to the root directory of the CFSv2 softwar
40. ntains several routines that involve gathering of sensor data and computing derived geometry infrared sea surface emissivity IRSSE for input wind speed frequency and angles surface emissivity and reflectivity at infrared 22 CDAC Climate Forecast System Vn 2 0 frequencies surface optical properties tangent linear surface emissivity and reflectivity at infrared frequencies for land surface water surface snow surface and ice surface esmf Earth System Modeling Framework The Earth System Modeling Framework ESMF collaboration is building high performance flexible software infrastructure to increase ease of use performance portability interoperability and reuse in climate numerical weather prediction data assimilation and other Earth science applications The ESMF defines an architecture for composing complex coupled modeling systems and includes data structures and utilities for developing individual models The ESMF library is responsible for representing large scale physical domains i e atmosphere and ocean components It creates a coupler that intermediates the data between these components Grid interpolation and re mapping are core utilities of ESMF It also creates an ESMF Grid object and sets up its internal structure so that it is usable for other Grid methods ESMF takes care of reading the coordinates to form appropriate grids Re gridding is based on bi linear or bi cubic interpolatio
41. on all the executables will be kept in the directory SCFSROOT exec How to build only utility modules iv Before starting the installation of utility modules user should make sure that all the dependency libraries are built successfully Enter 3 as your choice The installer asks the choice from the user Select the utility module which you want to install 1 or 2 1 All 2 Select from the list After the successful installation all the utility executables will be kept in the directory SCFSROOT util exec B Install the entire model Enter 4 as your choice This option installs the entire model The installer keeps updating the user about the progress of the installation and also reports about the success or failure of each library source or utility module The user can also check the installation log log install in the directory SCFSROOT build to verify whether the model is installed without errors or not After the successful installation v The libraries will be placed in the directory SCFSROOT lib and the module files for the libraries in SCFSROOT incmod v All the executables of the source modules will be kept in the directory SCFSROOT exec v All the utility executables will be placed in SCFSROOT util exec 7 After all the libraries source modules and utility modules have been successfully built user can run CFSv2 using the run instructions described i
42. ospheric Climate Data Assimilation System version 2 CDAS2 is upgraded from T62 210 km with 28 sigma levels to T574 27km with 64 hybrid sigma pressure levels e Changing the Spectral Statistical Interpolation scheme SSI to a Gridpoint Statistical Interpolation scheme GSI e Assimilating Satellite radiances directly instead of retrievals e Upgrading the Global Ocean Data Assimilation GODAS from MOM3 to MOM4 e In addition introducing a new Global Land Data Assimilation GLDAS which uses observed CPC precipitation as forcing for the NOAH land model e Significant additions to parameters in the pressure GRIB pgb flux files flx and ocean ocn files e In addition there is a new file that contains parameters on Isentropic surfaces ipv e Significant changes to the format and content of all the model files due to the increases in resolution The horizontal resolution of pgb files is increased from 2 5 x 2 5 to 1 x 1 and the number of pressure levels is increased from 17 to 37 The size of the flux file is increased from the Gaussian grid for T62 192 x 94 to that for T126 384 x 190 The ocean file is increased from 2 5 x 2 5 to 0 5 x 0 5 The new Isentropic file has a resolution of 1 x 1 e There is also an increase in the temporal resolution of the output forecast data from 12 hourly to 6 hourly CDAC Climate Forecast System Vn 2 0 2 3 CFSv2 Retrospective Forecasts at NCEP
43. put file then ozone is generated from climatology and optionally a total ozone grib field The last record precipitation is also interpolated if requested The procedure for changing the surface file resolution is thus 13 CDAC User s Manual Nearest neighbor interpolation is performed so that land non land points on the input grid are mapped to land non land points on the target grid If the input file contains land ice and the output grid is to have land ice then non land is mapped to non land land ice is mapped to land ice ice free land is mapped to ice free land Optionally the fields such as albedo roughness etc may be determined on the output grid from sfccycle which is called from the surface chgres module The latter is recommended when converting from a low to high resolution grid A new land sea mask is optionally read in If it is missing the new land sea mask is interpolated from the old mask Skin and soil temperature over land are adjusted for differences between the input and output orography Liquid soil moisture is calculated according to the adjusted temperature Output orography may be read in from file or interpolated from input orography Note Older versions of the surface restart file before ivs 200501 do not have orography records In cases where the input surface file is pre 200501 the program will get the orography from the sigma file Therefore you must set the options to convert a sigma file as well a
44. s a surface file When changing a pre 200501 file the program will interpolate only those land fields needed to run the old OSU land model and old sea ice physics When changing a 200501 file the program will interpolate calculate those additional fields needed by the NOAH LSM max snow albedo liquid Soil moist snow depth precipitation precipitation type slope type max min greenness and the new sea ice model ice depth and fraction When changing a pre 200501 file to a 200501 file the program will automatically initialize the above mentioned fields using either guess values or values calculated from sfccycle The program will also convert from two to four soil layers and vice versa The program will run on the full or reduced grid depending on the lonsperlat record of the input file or whether the user specifies an external lonsperlat file The program will initialize all land states for the land ice physics if desired The program will scale total soil moisture for any differences in soil type between the input and output grids 2 Dir ncep_post_new fd Exec ncep_post This module takes model output in Gaussian native grid and writes them out in GRIB format It interpolates data from model to model surfaces ISOBARIC PRESSURE surfaces Above Ground Level AGL height surfaces and THETA amp PV surfaces Currently the post processor 14 CDAC Climate Forecast System Vn 2 0 outputs 405 fields RQSFLD f Sample fields generate
45. tains the model installer and the compiler options files This directory contains all the executables for model components This directory typically contains configuration files rlists and submit script Fix files for different model components This directory contains the initial conditions to start the model These scripts combined with variable definitions setin configuration call the main driver scripts This directory contains the model libraries and the corresponding sources parms This directory contains the control parameters files for model components scripts Development versions of the main driver scripts sorc ush util com Source directories for all model parts Additional scripts to invoke model components typically called from within the main driver scripts This directory contains utility scripts and executables for running the model Working and Output directory CDAC Climate Forecast System Vn 2 0 3 2 Functionality of model components and scripts 3 2 1 Source Modules 1 Dir global_chgres fd Exec global_chgres This program changes the resolution of the sigma and surface restart files from the global spectral model The input files should have header records identifying their respective resolutions The output file s resolution is specified in the namelist file namchg Either the input sigma or surface file may be missing in which case no counterpart file is created
46. tal of 17520 forecasts The forecast from the OZ cycle was run out to a full season required to calibrate the operational CPC first season predictions for hydrological forecasts precip evaporation runoff streamflow etc while the forecasts from the other 3 cycles 6 12 and 18Z were run out to exactly 45 days required for the operational CPC week3 week6 predictions of tropical circulations MJO PNA etc Saha et al 2013 Smoothed calibration climatologies have been prepared from the forecast time series of selected variables http cfs ncep noaa gov cfsv2 info CFSv2 Calibration Data doc and is CDAC User s Manual available for download It is essential that some smoothing is done when preparing the climatologies of the daily time series which are quite noisy Jan 1 Jan 2 Jan 3 Jan 4 Jan 5 Jan 6 061218 061218 061218 061218 061218 061218 9 month run gt 1 season run 45 day run Figure 2 3 CFSv2 Retrospective Forecasts 2 3 3 Operational Configuration The initial conditions for the CFSv2 retrospective forecasts are obtained from the CFSR while the real time operational forecasts obtain their initial conditions from the real time operational CDASv2 Great care was made to unify the CFSR and CDASv2 in terms of cutoff times for data input to the atmosphere ocean and land surface components in the data assimilation system Therefore there is greater utility of the new system as compared to CFSv1 which had a
47. ule reads all or part of one GRIB file computes climate anomalies and writes the anomalies to another GRIB file interpolating if necessary Only geopotential height anomalies are computed in the current implementation Unless otherwise directed x option the GRIB index file is also used to speed up the reading The fields are interpolated to an output grid if specified g option The interpolation type defaults to bilinear but may be specified directly i option The copying may be limited to specific fields k option The command may be directed to output verbose diagnostics X option If grib2 is the output GRIB file is written to standard output copygb Copygb copies all or part of one GRIB file to another GRIB file interpolating if necessary Unless otherwise directed x option the GRIB index file is also used to speed up the reading The fields are interpolated to an output grid if specified g option The interpolation type defaults to bilinear but may be specified directly i option The copying may be limited to specific fields k option It may also be limited to a specified subgrid of the output grid or to a subrange of the input fields B and b A and K options Fields can be identified as scalars or vectors v option which are interpolated differently The invalid data in the output field can be filled with mask values or merged with a merge field M and m options The output GRIB message can also
48. with the new resolution The procedure for changing the sigma file resolution is thus A new orography is optionally read in If it is missing the new orography will be the transform of the old orography A new sigma structure is also read in This file is only optional if the number of levels are the same in which case the new sigma structure defaults to the old sigma structure Then the input spectral fields are read in and transformed to the new Gaussian grid A new surface pressure is calculated hydrostatically based on the new orography Then the upper air fields are vertically interpolated to the inferred new pressures The vertical interpolation is generally cubic Lagrangian in log pressure with a monotonic condition that a new value cannot exceed the range of its immediate old neighbors Interpolation is linear between the two outer intervals of the old domain Fields are held constant outside the old domain except for temperature and humidity below the old domain where the temperature lapse rate is held fixed at 6 5 k km and the relative humidity is also held fixed Finally all fields are transformed to the new spectral space and written out Note that all tracers are interpolated unless requested otherwise Alternatively if no transforms are needed then no new orography or sigma structure is read in and the spectral coefficients are directly padded or truncated Furthermore if ozone is requested in the output file but is not in the in
49. z coordinate ocean model MOMA4 has been coded within GFDL s Flexible Modeling System FMS Doing so allows for MOM4 developers to use numerous FMS infrastructure and superstructure modules that are shared amongst various atmospheric ocean sea ice land vegetative etc models The following list represents a sample of the FMS shared modules used by MOMA 1 time manager keeps time and sets time dependent flags 2 coupler and data override used to couple MOM4 to other component models and or datasets I O to read and write data initial and boundary data regrids spherical fields to the generally non spherical ocean model grid 5 grid and topography specification sets model grid spacing and interpolates spherical topography to the model grid 6 parallelization tools for passing messages across parallel processors diagnostic manager to register and send fields to be written to a file for later analysis 8 field manager for organizing multiple tracers for use especially in bio geochemistry studies 16 CDAC Climate Forecast System Vn 2 0 The complete model documentation and the MOM4 Manual can be obtained from http data1 gfdl noaa gov arl pubrel o old doc mom4p0 guide pdf and http data1 gfdl noaa gov arl pubrel o old doc mom4 manual html respectively 7 Dir cfs_overparm_grib fd Exec cfs_overparm_grib This module reads an entire GRIB file and writes it back out replacing the internal parameter table version and
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