NCEP / NCAR Global Reanalysis Data
Left = Nodes Covering Western Europe. Right = Nodes Covering France.
Data from the NCEP/NCAR reanalysis project is currently available to users of WindPRO as part of the on-line services from the EMD server. A connection to the internet is thus required. Users may download updated data from the present moment (typically the preceding month) back until 1948. The sub-set of the NCEP/NCAR Global Reanalysis Data that we hold at EMD is updated on a monthly to bi-monthly update cycle.
Data Description
The NCEP/NCAR model dataset is immense, containing a very wide range of descriptive atmospheric model data. The actual measured climate data sources used in the global reanalysis model are:
- Upperair rawinsonde observations of temperature, horizontal wind, and specific humidity (i.e. weather balloons)
- Operational Television Infrared Observation Satellite (TIROS) Operational Vertical Sounder (TOVS) vertical temperature soundings from NOAA polar orbiters over ocean, with microwave retrievals excluded between 20°N and 20°S due to rain contamination
- TOVS temperature soundings over land only above 100 hPa
- Cloud-tracked winds from geostationary satellites
- Aircraft observations of wind and temperature
- Land surface reports of surface pressure
- Oceanic reports of surface pressure, temperature, horizontal wind, and specific humidity
These data are used as input into a frozen global assimilation system and processed by a spectral model in order to provide the model output of the variables in the grid.
NCEP/NCAR Global Reanalysis Dataset at EMD
Currently, two types of NCEP/NCAR modeled wind data are available from the EMD server. Both types of data are distributed through the NCAR_Basic dataset from the EMD server. The raw data are processed by EMD as the original data holds the vector components for the wind speeds only (U and V – winds). We convert the raw data into a format appropriate for use with wind turbine applications, i.e. wind speed and direction instead.