CFS- and CFSR Data

CFSR Logo (Credit: NOAA)

The CFSR is a third generation reanalysis product. It is a global, high resolution, coupled atmosphere-ocean-land surface-sea ice system designed to provide the best estimate of the state of these coupled domains over this period. The CFSR includes (1) coupling of atmosphere and ocean during the generation of the 6 hour guess field, (2) an interactive sea-ice model, and (3) assimilation of satellite radiances.

Model Resolution and Coverage

EMD holds a subset of the CFSR data in different spatial resolutions.

1. 0.5 degree resolution (CFSR-E, period 1979-present)
2. 0.3 degree resolution (CFSR v.1, period 1979-2010)
3. 0.2 degree resolution (CFSR v.2, period 2011-present)

All have a global coverage over land masses which is extended about 50 km into the sea near coastlines. The temporal resolution is 1 hour. Currently only the 0.5 degree data is available from within WindPRO.

Note that the CFSR-E dataset is actually a version of the CFSR v.1 that has been extended with data from CFSR v. 2. According to NCEP, this can be regarded as a 'seamless' extension (however see our experiences below).

The Model

Example of CFSR data (Credit: NOAA)

The CFSR global atmosphere resolution is ~38 km (T382) with 64 levels. The global ocean is 0.25° at the equator, extending to a global 0.5° beyond the tropics, with 40 levels. The global land surface model has 4 soil levels and the global sea ice model has 3 levels. The CFSR atmospheric model contains observed variations in carbon dioxide (CO2), together with changes in aerosols and other trace gases and solar variations. With these variable parameters, the analyzed state will include estimates of changes in the Earth system climate due to these factors.

More information available at: https://climatedataguide.ucar.edu/reanalysis/climate-forecast-system-reanalysis-cfsr

Data Availability in 0.5 degree Dataset

CFSR data on the 0.5 degree grid is commonly available within WindPRO with a time-tag of 1-2 months. This is due to the processing time of the data at NOAA and the subset-processing at EMD. When the data has been processed at EMD, then the following parameters are available from within the online-dataservices WindPRO.

Table: Overview of CFSR-Extended Dataset Parameters (0.5 degree grid).

Parameter	Description
time	UTC time stamp
wSpeed.10	Wind speed at 10 m above surface
wDir.10	Wind direction at 10 m above surface
wSpeedAtPressure.500	Wind speed at 500 hPa pressure level (approx 5500 m)
wDirAtPressure.500	Wind direction at 500 hPa pressure level (approx 5500 m)
wSpeedAtPressure.850	Wind speed at 850 hPa pressure level (approx. 1500 m)
wDirAtPressure.850temperatureAtPressure.1000	Wind direction at 850 hPa pressure level (approx. 1500 m)
temperatureAtPressure.1000	Wind direction at 1000 hPa pressure level (approx. at sea level)

Data Experiences

The CFSR-Extended dataset may suffer for inconsistencies if periods before and after end of 2010 are compared, even if NOAA has described the extended data as seamless. Such inconsistencies is probably due different native model resolutions of the CFSR v.1 and CFSR v.2 (0.3 degrees and 0.2 degrees). Please investigate this consistency issue thoroughly, if you are using CFSR-Extended data in your wind farm project.

Comparing 7 years of CFSR data vs. MERRA and NCEP/NCAR Reanalysis data. Monthly average wind speeds are shown. At this offshore-site in Denmark, no obvious divergence of datasets are seen.

Comparing 7 years of CFSR data vs. MERRA and EMD-Conwx data. Monthly average wind speeds are shown. At this mountaneous-site in Norway, an obvious divergence of datasets are seen.

External Links

• The full CFSR data-set is available at UCAR http://rda.ucar.edu/pub/cfsr.html
• CFSR model description at NOAA: http://cfs.ncep.noaa.gov/cfsr/
• BAMS Paper on CFSR model by S. Shaha et al: The NCEP Climate Forecast System Reanalysis: http://journals.ametsoc.org/doi/pdf/10.1175/2010BAMS3001.1