NCEP North American Regional Reanalysis Data
The NCEP North American Regional Reanalysis Data is a high resolution high frequency assimilated dataset covering the North American region. The model area is shown in the figure to the right.
Resolution
The spatial resolution is 32.4 km, resulting in a total of 96673 nodes covering the area. The temporal resolution is 3 hours. The dataset covers a period from 1979 until the present moment. The dataset assimilates data from rawinsondes, dropsondes, pibals, aircraft, selected surface stations and geostationary satellites.
The full dataset consists of more than 400 climate variables which – when stored in NetCDF files – require storage of about 30 Terra Bytes. At EMD we hold and distribute a subset of the NARR data. The raw data is 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.
NARR Dataset at EMD
The NARR dataset at EMD currently holds 10 m and 30 m wind speeds as well as 2 m temperature data. An overview of the data is given in the tables below. Please refer to these tables when interpreting the headers in the files received from the EMD server.
| Name | Description |
|---|---|
| Abbreviation | u10 = 10 minute averaged wind speeds |
| External URL | http://www.emc.ncep.noaa.gov/mmb/rreanl/ |
| Data valid at time | Data valid at the analysis/reference time |
| Referred to as | "Wind” at level: "10 m above ground level” or “30 m above ground level” |
| Level | 10 m above ground |
| Grid | Regional - NOAMHI - High Resolution North American Master Grid. Lambert Conformal with 349 x 277 nodes. |
| Coverage | North America |
| Columns in data-file | u10.dir.10 = Wind Direction at 10 m a.g.l u10.wsp.10 = Wind Direction at 10 m a.g.l u10.dir.30 = Wind Direction at 30 m a.g.l u10.wsp.30 = Wind Direction at 30 m a.g.l |
| Name | Description |
|---|---|
| Abbreviation | tmp = temperature |
| External URL | http://www.emc.ncep.noaa.gov/mmb/rreanl/ |
| Data valid at time | Data valid at the analysis/reference time |
| Referred to as | "temperature” at level: "surface" under main title "Surface Fluxes" |
| Grid | Regional - NOAMHI - High Resolution North American Master Grid. Lambert Conformal with 349 x 277 nodes. |
| Coverage | North America |
| Columns in data-file | tmp.2 = Temperature at 2 m a.g.l. (in degrees Celsius) |
External Links
- Homepage for Regional Reanalysis Questions and Answers at http://www.emc.ncep.noaa.gov/mmb/rreanl
- For a detailed overview of the NARR model, please refer to the paper by F. Mesinger et al (see below). The paper may be located at the following URL: http://www.emc.ncep.noaa.gov/mmb/rreanl/.
References
Fedor Mesinger, Geoff DiMego, Eugenia Kalnay, Kenneth Mitchell, Perry C. Shafran, Wesley Ebisuzaki, Dusan Jovic, Jack Woollen, Eric Rogers, Ernesto H. Berbery, Michael B. Ek, Yun Fan, Robert Grumbine, Wayne Higgins, Hong Li, Ying Lin, Geoff Manikin, David Parrish, and Wei Shi: North American Regional Reanalysis, Paper Submitted to the Bulletin of the AMS, 2005