Willmott and Feddema's Moisture Index Archive:
Gridded Monthly Climatologies

 (Version 1.02)

produced and documented by

Cort J. Willmott and Kenji Matsuura
(with support from NASA's Seasonal to Interannual ESIP)

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

Center for Climatic Research
Department of Geography
University of Delaware
Newark, DE 19716
(302) 831-2294

or

kenjisan@udel.edu


Archive (Version 1.02) released July 1, 2001

STATION AND GRIDDED DATA SOURCES:

Gridded (at a 0.5 x 0.5 degree resolution) mean monthly total potential evapotranspiration (Eo) and unadjusted (for raingage undercatch) total precipitation (P) were taken from the Terrestrial Water Balance Data Archive: Regridded Monthly Climatologies (V. 1.02) and the Terrestrial Air Temperature and Precipitation: Monthly and Annual Climatologies (V. 3.02) which are also available from this web site. Our estimates of the average-monthly moisture indices from Eo and P were made at (and are available for) only the land-surface grid points, which number 85,794.

GRIDDED MOISTURE INDEX ESTIMATES:

Using the gridded average-monthly total (Eo) and P values, average-monthly moisture indices were calculated according to Willmott and Feddema (1992) at the same resolution as the water-balance fields.

ARCHIVE STRUCTURE:

There is one file containing the fields. Please note that each mean-annual moisture index was computed from the 12-month totals of Eo and P.

FieldColumns
Variable
Fortran Format
11 - 8 Longitude (decimal degrees)
F8.3
29 - 16 Latitude (decimal degrees)
F8.3
3-1417 - 112 Monthly Moisture Indices
12F8.2
15113 - 120 Annual Moisture Indices
F8.2


SELECTED REFERENCES:

Willmott, C. J., C. M. Rowe, and Y. Mintz, 1985. 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.