1. Forecast system version

Identifier code: CFSv2

First operational forecast run: 15 March 2011

2. Configuration of the forecast model

Is the model coupled to an ocean model?   Yes

Coupling frequency: One hour (between atmosphere and open water)

2.1 Atmosphere and land surface

ModelNCEP Global Forecast System
Horizontal resolution and gridT128 (~ 1x1 Deg Lat/Lon)
Atmosphere vertical resolution64 Levels (sigma-pressure hybrid coordinates)
Top of atmosphere0.02 hPa
Soil levels (layers)

Layer 1: 0-10 cm
Layer 2: 10-40 cm
Layer 3: 40-100 cm
Layer 4: 100-200 cm 

Time step10 minutes

Detailed documentation:

2.2 Ocean and cryosphere

Ocean modelGFDL MOM4
Horizontal resolutionSpatial resolution in the zonal direction of 0.5° and in the meridional direction, 0.25° from 10°S to 10°N, progressively decreasing to 0.5° from 10° to 30°, and is fixed at 0.5° beyond 30° in both hemispheres.
Vertical resolution40 Layers
Time step1 hour
Sea ice modelGFDL Sea Ice Simulator (part of GFDL MOM4 ocean model)
Sea ice model resolutionSea ice model is on a tripolar grid; Resolution in polar regions is about 50x50 Km
Sea ice model levelsThree; one snow layer, and two equal-thickness ice layers.
Wave modelNot Applicable
Wave model resolutionNot Applicable

Detailed documentation:

3. Initialization and initial condition (IC) perturbations

3.1 Atmosphere and land


HindcastForecast
Atmosphere initialization
Every 5th day of the calendar month from Climate Forecast System Reanalysis (CFSR)Everyday from Climate Forecast System Reanalysis (CFSR)
Atmosphere IC perturbationsForecasts are initialized from each 6 hourly analysis cycle. No additional perturbations are added to the analysis.Same as for the hindcast.

Land Initialization

From the Climate Forecast System Reanalysis (CFSR)From the Climate Forecast System Reanalysis (CFSR)
Land IC perturbationsNo explicit perturbations added.No explicit perturbations added.
Soil moisture initializationFrom the Climate Forecast System Reanalysis (CFSR)From the Climate Forecast System Reanalysis (CFSR)
Snow initializationFrom the Climate Forecast System Reanalysis (CFSR)From the Climate Forecast System Reanalysis (CFSR)
Unperturbed control forecast?NoneNone

Data assimilation method for control analysis: Climate Forecast System Reanalysis (CFSR); 3DVAR

Horizontal and vertical resolution of perturbations:  N/A

Perturbations in +/- pairs: N/A

Detailed documentation:

3.2 Ocean and cryosphere


HindcastForecast
Ocean initializationCFSRCFSR
Ocean IC perturbationsNo explicit perturbations added to the analysisNo explicit perturbations added to the analysis
Unperturbed control forecast?NoneNone

Detailed documentation:


4. Model Uncertainties perturbations:

Model dynamics perturbationsNo
Model physics perturbationsNo

If there is a control forecast, is it perturbed?

No

Detailed documentation: 

5. Forecast system and hindcasts

Forecast frequencyEvery day
Forecast ensemble sizeFour/day
Hindcast years1981-2010
Hindcast ensemble sizeFour/start date
Hindcast start datesEvery 5 days
(see full list below)
On-the-fly or static hindcast set?Static hindcast


6. Other relevant information

The available hindcast start dates are as follows:

Start MonthAvailable Start Days
January

1, 6, 11, 16, 21, 26 and 31

February5, 10, 15, 20 and 25
March2, 7, 12, 17, 22 and 27
April1, 6, 11, 16, 21 and 26
May1, 6, 11, 16, 21, 26 and 31
June5, 10, 15, 20, 25 and 30
July5, 10, 15, 20, 25 and 30
August4, 9, 14, 19, 24 and 29
September3, 8, 13, 18, 23 and 28
October3, 8, 13, 18, 23 and 28
November2, 7, 12, 17, 22 and 27
December2, 7, 12, 17, 22 and 27

7. Where to find more information

General information:

https://cfs.ncep.noaa.gov/

Comprehensive description of the model components:

Ek, M. B., K. E. Mitchell, Y. Lin, E. Rogers, P. Grunmann, V. Koren, G. Gayno, and J. D. Tarplay, 2003: Implementation of Noah land surface model advances in the National Centers for Environmental Prediction operational mesoscale Eta model. J. Geophys. Res., 108, 8851, doi:10.1029/2002JD003296.

Kumar, A., and Co-authors, 2012: An Analysis of the Non-stationarity in the Bias of Sea Surface Temperature Forecasts for the NCEP Climate Forecast System (CFS) Version 2. Mon. Wea. Rev., 140 ,3003-3016. https://journals.ametsoc.org/doi/full/10.1175/MWR-D-11-00335.1

Saha, S., and Coauthors, 2010: The NCEP Climate Forecast System Reanalysis. Bull. Amer. Meteor. Soc., 91, 1015.1057. doi: 10.1175/2010BAMS3001.1

Saha, S. and Coauthors, 2014: The NCEP Climate Forecast System Version 2 J. Climate, 27, 2185–2208. doi: http://dx.doi.org/10.1175/JCLI-D-12-00823.1

https://ral.ucar.edu/sites/default/files/public/product-tool/unified-noah-lsm/Noah_LSM_USERGUIDE_2.7.1.pdf

Zobler, L. 1986. A World Soil File for Global Climate Modelling. NASA Technical Memorandum 87802. NASA Goddard Institute for Space Studies, New York, New York, U.S.A.