JISAO data

Selected NCEP / NCAR Reanalysis fields

4-times daily, daily, and monthly averages of the NCEP/NCAR reanalysis are available from the NOAA Climate Diagnostics Center. The present WWW page provides selected fields that we have calculated for research purposes at JISAO.

Pentad | Monthly data

Climatological-mean and standard deviation of DJF 500 hPa geopotential height, 1979-95
Image of 
Northern Hemisphere extratropics.
Contours are drawn for the 546 and 528 dam geopotentials, and shading indicates regions with standard deviations > 60 m. Climatological ridges are located on the west coasts of North America and Europe, with the largest variability upstream of the ridges.

Pentad-mean data:
At JISAO, the data resides at /home/disk/margaret/data/ncep_reanalysis/pentad
200mb geopotential height, 1948-99 (80 Mb)
Tropopaus pressure, 1948-99 (80 Mb)
500mb geopotential height, 1958-99 (64 Mb)
500mb zonal wind, 1948 - June 2002 (84 Mb)
500mb meridional wind, 1948 - June 2002 (84 Mb)
600mb omega, 1958-97 (61 Mb)
850 hPa air temperature, 1948-2000 (81 Mbytes)
925mb zonal wind, 1948-99 (80 Mb)
925mb meridional wind, 1948-99 (80 Mb)
0.995 sigma (lowest model level) air temperature, 1948-2002 (84 Mb)
sea-level pressure, 1948 - 2010 (193 Mb)
All errors in the calculation and writing of the pentad-mean fields are due to Todd Mitchell. For leap years, the twelfth pentad (February 25 through March 1) is the average of six days. The pentad-means are calculated from daily-average data obtained at various times from the NCEP / NCAR reanalysis project archive at the NOAA Climate Diagnostics Center. On some of the files the "history" variable ("ncdump -h filename.nc") says when the daily data was obtained. Users are encouraged to visit the NOAA CDC site to become more familiar with the data available and the problems identified with this product.

Monthly-mean data:
At JISAO, the data resides at /home/disk/margaret/data/ncep_reanalysis/monthly/

Kistler, R., E. Kalnay, W. Collins, S. Saha, G. White, J. Woollen, M. Chelliah, W. Ebisuzaki, M. Kanamitsu, V. Kousky, H. van den Dool, R. Jenne, M. Fiorino, 2001: The NCEP-NCAR 50-Year Reanalysis: Monthly Means CD-ROM and Documentation. Bull. Amer. Meteor. Soc., 82, 247-268.

December 2010
Todd Mitchell ( mitchell@atmos.washington.edu )
JISAO data