JISAO data

Legates / MSU Precipitation Climatology

John M. Wallace, Todd P. Mitchell, and Alexis K. -H. Lau

Data | Analyses

This WWW page contains analyses and data for a global precipitation climatology that has been produced at JISAO. The spatial resolution of this climatology is 2.5 degrees latitude-longitude. The land data for this climatology is taken from the Legates and Willmott (1990), which is based on historical rain gauge measurements. The ocean precipitation estimates are from the Microwave Sounding Unit (MSU) (Spencer 1993) for the years 1979 to 1992.

Spencer and collaborators developed a new MSU precipitation product ("Limb90"), and I got part way through merging it with the Legates and Willmott climatology. This work was never satisfactorily finished, but it is linked here. MSU has difficulty differentiating sea ice from very heavy rainfall, and it is pretty difficult to remove the erroneous gridpoints in a simple manner.


  • Legates, D. R. and C. J. Willmott, 1990. Mean seasonal and spatial variability in gauge-corrected, global precipitation. Int. J. Climatology, 10, 111-127.
  • Spencer, R. W., 1993: Global oceanic precipitation from the MSU during 1979-91 and comparisons to other climatologies. J. Climate, 6, 1301-1326.

    1) Merged data set.
    Each map contains complete fields of data (no missing values).

  • netCDF (0.25 Mb) (cm/month)
  • ASCII compressed (0.3 Mb) (mm/month).
  • ASCII uncompressed (1.0 Mb) (mm/month).
    The first grid point of the ASCII versions are centered at 88.75 S, 1.25 E; the second grid point at 88.75 S, 3.75 E; and so forth. The global data values for January are given first, then the global data values for February, and so forth. The data was written in FORTRAN with an 8f8.2 format. A simple FORTRAN code to read the climatology is linked here.

    2) Rain gauge data component.

  • The Legates and Willmott rainfall climatology is available in ASCII format in 0.5-degree latitude-longitude resolution from the National Center for Atmospheric Research.
  • The University of Delaware (Willmott) provides several data sets at their WWW site.





    Monthly mean precipitation over the Pacific and Atlantic (744K)
    Monthly mean precipitation over the Indian Ocean (544K)

    Annual Total (mm): large GIF | PDF | PNG

    Individual Calendar Months (mm month-1)

    A PDF file containing all of the monthly analyses is linked here.

    January: large GIF | PDF | PNG

    February: large GIF | PDF | PNG

    March: large GIF | PDF | PNG

    April: large GIF | PDF | PNG

    May: large GIF | PDF | PNG

    June: large GIF | PDF | PNG

    July: large GIF | PDF | PNG

    August: large GIF | PDF | PNG

    September: large GIF | PDF | PNG

    October: large GIF | PDF | PNG

    November: large GIF | PDF | PNG

    December: large GIF | PDF | PNG

    July 1995
    Todd Mitchell (mitchell@atmos.washington.edu)
    JISAO data