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Monsoon Desk


GSI GSI Documents and Publications (DTC)
GSI User Guide v3.2 (DTC)
GSI User Guide v3.0 (DTC)
Introduction of the GSI into the NCEP Global Data Assimilation System (full ref) (NCEP)
GFS-GSM Documentation (NCEP/EMC)
Performance of T254L64, T382L64 and GEFS Global Assimilation Forecast System (NCMRWF) - Monsoon-2008 (pdf), Monsoon-2009 (pdf),Monsoon-2010 (pdf),Monsoon-2012 (pdf)
Experimental real-time multi-model ensemble (MME) prediction of rainfall during monsoon 2008: Large-scale medium-range aspects (pdf) (NCMRWF)
CFS Documentation (NCEP/EMC) Development of Extended range prediction system using CFSv2 and its verification - Report(pdf)



Obtain ICs from NOMADS: 1-month rotating GDAS/GFS archive (gdas.YYYYMMDD or gfs.YYYYMMDDCC)

Parallel Convention<-- Operational Convention
biascr.CDUMP.CDATE<--CDUMP.tCCz.abiasA, NCDATE = YYYYMMDDCC (year, month, day, cycle), CC = cycle
CDUMP = dump (gdas1 or gfs)

A - required if cycling with analysis
F - required if running forecast
N - not available for gfs dump
satang.CDUMP.CDATE<--CDUMP.tCCz.satangA, N
sfcanl.CDUMP.CDATE<--CDUMP.tCCz.sfcanlA, F
siganl.CDUMP.CDATE<--CDUMP.tCCz.sanlA, F


Obtain ICs from NOMADS: 7-day rotating CDAS archive (cdas.YYYYMMDD)

Parallel Convention<-- Operational ConventionCDATE = YYYYMMDDCC (year, month, day, cycle), CC = cycle

A - required if cycling with analysis
F - required if running forecast
sfcanl.gdas.CDATE<--cdas1.tCCz.sfcanlA, F
siganl.gdas.CDATE<--cdas1.tCCz.sanlA, F
ocnanl.gdas.CDATE.tar<--cdas1.tCCz.ocnanl.tarA, F



Basic how-to-run steps for GFS and CFS (assumes model/system is installed and working and that all scripts/code are under a para directory structure):

  1. Setup directories
    • EXPDIR - experiment directory, where your configuration file, rlist, and other necessary text files and scripts live
    • ROTDIR - rotating directory, where initial conditions are placed before run and where output from run will appear
    • DATATMP - temporary working directory, usually scrub space
  2. Obtain initial conditions (ICs)
    • See Initial Condition file information above
    • Place initial condition files in ROTDIR prior to run
  3. Setup configuration file
    • Obtain sample configuration file (from para/exp directory or elsewhere)
    • Adjust variable settings in configuration file for your run (more information on this coming!)
  4. Submit run
    • Using psub (recommended to be run from EXPDIR)
      • psub script - found in para/bin
      • wrapper script that utilized the sub script to submit each step of the run
      • run with command line arguments: $PSUB $CONFIG $CDATE $CDUMP $CSTEP
      • Where:
        • $PSUB = full path location of psub script (example: $HOMEDIR/para/bin/psub, where $HOMEDIR is rest of path)
        • $CONFIG = name of configuration (including path of file if not submitting run inside EXPDIR)
        • $CDATE = YYYYMMDDCC, starting cycle of run
        • $CDUMP = gdas or gfs*, starting dump of run (* not option for CFS runs)
        • $CSTEP = starting step of run (recommended that first time users start on "fcst1" step)
    • Using submit script (information coming soon!)



3D/4D-Var Three/Four Dimensional Varioational Method (for data asssimilation)
4DDA Four Dimensional Data Assimilation (for data asssimilation)
AC Anomaly Correlation
CFS Climate Forecast System
CFSv2 Climate Forecast System version 2.0.0
CPC Climate Prediction Center (NCEP) - visit website
DTC Developmental Testbed Center (Boulder, CO) - visit website
ECMWF European Centre for Medium-Range Weather Forecasts, Europe - visit website
EMC Environmental Modeling Center (NCEP) - visit website
EnKF Ensemble Kalman Filter (data asssimilation method)
ESSO Earth System Sciences Organisation, India
GDAS Global Data Assimilation System, the late run of the GFS, a short 9-hr forecast utilizing late arriving data, provides guess fields / initial conditions for next GFS cycle. Example: 18z GDAS provides initial conditions for 00z GFS
GFS Global Forecast System (entire suite of systems: GSI, GSM, CFS), commonly used to refer to forecast output from entire coupled system although forecast actually comes from the GSM
GSI Gridpoint Statistical Interpolation, GFS data assimilation system
GSM Global Spectral Model, forecast model in GFS
HWRF Hurricane Weather Research and Forecast System - visit website
IC(s) initial condition(s) for model
IITM Indian Institute of Tropical Meteorology - visit website
IMD India Meteorological Department - visit website
INCOIS Indian National Centre for Ocean Information Services - visit website
MISO monsoon intraseasonal oscillations - visit website
MoES Ministry of Earth Sciences, India - visit website
MOK Monsoon over Kerala, onset of Monsoon in India - visit website
MOM4 Modular Ocean Model is the Ocean Model in GFS, developed by GFDL - visit website
NCEP National Centres for Environmental Prediction, USA - visit website
NCMRWF National Centre for Medium Range Weather Forecasting (Noida, India) - visit website
NOMADS NOAA National Operational Model Archive and Distribution System (NOMADS) is a Web-services based project providing both real-time and retrospective format independent access to climate and weather model data
T574 Triangular Spectral truncation. Domain shape is in spectral space and traingular is isotropic on sphere. 574 is the maximum number of waves around a great circle in any direction ; so the shortest wavelength is 40,000/574 = 70 km. Eulerian Global Spectral Model (GSM) uses 3 gridpoints per wave, on tranform grid of "1760 X 880" reduced Gaussian grid. The horizontal resolution at T574 becomes ~ 23 km
T382 Spectral truncation equivalent to horizontal resolution ~37 km
T254 Spectral truncation equivalent to horizontal resolution ~50-55 km
T190 Spectral truncation equivalent to horizontal resolution ~70 km
T126 Spectral truncation equivalent to horizontal resolution ~100 km
UM Unified Model by British Met Office, UK - visit website