These rankings are based on papers published and cited in more than 300 ISI-indexed geosciences journals between 1991 and June of 2001.

Among institutions, none garnered as many citations as NASA, the National Aeronautics and Space Administration. The citation figure for NASA reflects all of the organization's component facilities, including the Langley Research Center, the Johnson Space Center, the Ames Research Center, the Jet Propulsion Laboratory, etc. The decade's most-cited paper by NASA-affiliated authors concerned the International Satellite Cloud Climatology Project, discussed in a 1991 paper from the Bulletin of the American Meteorological Society by W.B. Rossow—ranked in the adjoining table at #10 among geosciences authors for the decade—and R.A. Schiffer (see "ISCCP cloud data products," Bull. Amer. Meteorol. Soc., 72[1]:2-20, 1991); this paper has been cited nearly 500 times [see the following page for table].

Ranking second in total citations is NOAA, the National Oceanic and Atmospheric Administration. The decade's most-cited NOAA paper appeared in the Journal of Climate in 1994 (see R.W. Reynolds, T.M. Smith, "Improved global sea-surface temperature analyses using optimum interpolation," J. Climate, 7[6]:929-48, 1994); this paper has been cited more than 450 times.

In the impact ranking, the decade's highest cites-per-paper score in geosciences was posted by the Max Planck Institute for Chemistry in Mainz, Germany. Not coincidentally, that institution is also the base of the most-cited author in this survey, Paul J. Crutzen, who gained worldwide fame when he shared the 1995 Nobel Prize in chemistry with Mario J. Molina and F. Sherwood Rowland for research on the depletion of atmospheric ozone by manmade aerosol pollutants. Crutzen's most-cited paper of the 1990s, with over 200 citations, appeared in the Journal of Geophysical Research-Atmospheres in 1993; among his collaborators was lead author James M. Russell, who is ranked at #14 on the list of geoscientists (see J.M. Russell, et al., "The halogen occultation experiment," J. Geophys. Res.-Atmos., 98:10777-97, 1993).

The #2-ranked scientist on the list, Minze Stuiver, emeritus professor at the University of Washington, is coauthor of the decade's most-cited geosciences paper, on radiocarbon dating (see M. Stuiver, P.J. Reimer, "Extended C-14 database and revised CALIB 3.0 C-14 age calibration program," Radiocarbon, 35[1]215-30, 1993). This paper has logged more than 1,200 citations [see the following page for table].

As might be expected given NASA's strong showing in the institutional ranking, seven NASA-affiliated researchers appear on the list of highly cited scientists. One of them, Piers J. Sellers (#12), currently based at the Johnson Space Center, will have the rare opportunity to make a firsthand observation of the earth's climate and atmosphere from above; he was selected for astronaut training in 1996 and is scheduled to make his first shuttle flight in 2002.

Among nations, the United States tallied the greatest number of papers and citations in geosciences during the decade (67,229 ISI-indexed papers; 625,927 citations, followed in citation totals by England (16, 659 papers; 128,067 citations), Canada (15,683 papers; 106, 344 citations), France (14,920 papers; 105,480 citations), and Germany (13,116 papers; 96,015 citations). 
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