Willmott and Feddema's Moisture Index Archive:
Monthly Time Series (1900 - 2010)

(Version 2.02)

produced and documented by

Cort J. Willmott and Kenji Matsuura
[with support from NASA's Innovation in Climate Education (NICE) Program]

For additional information concerning this archive,
please contact us at:

Department of Geography
University of Delaware
Newark, DE 19716
(302) 831-2294

or

kenjisan@udel.edu


Archive (Version 2.02) released in December, 2012


GRIDDED DATA SOURCES:

Time series of gridded monthly potential evapotranspiration (Eo) and total precipitation (P) were taken from the Terrestrial Water Budget Data Archive: Monthly Time Series (1900-2010) (Version 2.02) and the Terrestrial Precipitation: Monthly and Annual Time Series (1900-2010) (Version 3.02) archive, which also are available from this web site. The length of each grid-node time series is 111 years (from 1900 through 2010) and the grid points, which number 85,794, cover the land surface at a 0.5x0.5 degree resolution.

GRIDDED WATER-BUDGET ESTIMATES:

Monthly moisture-index fields were estimated from the gridded monthly Eo and P fields according to Willmott and Feddema (1992) at the same resolution as the water-budget fields.

ARCHIVE STRUCTURE:

There is one file (im.tar.gz) that includes the 111 yearly files. All yearly files have the same structure (once they are uncompressed). Please note that annual moisture index was computed from the 12-month totals of Eo and P.


Field Columns Variable Fortran Format
1 1 - 8 Longitude (decimal degrees)
F8.3
2 9 - 16 Latitude (decimal degrees)
F8.3
3-14 17 - 112 Monthly Moisture Indices
12F8.2
15 113 - 120 Annual Moiture Indices
F8.2


SELECTED REFERENCES:

Willmott, C. J., C. M. Rowe, and Y. Mintz, 1985b. Climatology of the Terrestrial Seasonal Water Cycle. Journal of Climatology, 5, 589-606.

Willmott, C. J. and J. J. Feddema, 1992. A More Rational Climatic Moisture Index. Professional Geographer, 44(1), 84-88.