NCEP North American Regional Reanalysis Data

From Wiki-WindPRO
Jump to navigation Jump to search
The NCEP 221 Grid used in the NARR model

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.

Table: NARR 10 m and 30 m wind data.
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
Table: 2 m temperature data.
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

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