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The Vegetation/Ecosystem Modeling and Analysis Project (VEMAP) Phase 2 has developed a number of transient climate change scenarios based on coupled atmosphere-ocean general circulation model (AOGCM) transient climate experiments. The purpose of these scenarios is to reflect time-dependent changes in surface climate from AOGCMs in terms of both (1) long-term trends and (2) changes in multiyear (3-5 yr) to decadal variability patterns, such as El Nino/Southern Oscillation(ENSO). Development of the data set is reported in Kittel et al. (1997).

Scenarios have been derived from transient greenhouse gas experiments with sulfate aerosols from the Canadian Climate Center (CCC) and the Hadley Centre (HADCM2; Mitchell et al. 1995, Johns et al. 1997) accessed via the Climate Impacts LINK Project, Climatic Research Unit, University of East Anglia. Scenarios were developed for the following variables: total incident solar radiation, minimum and maximum temperature, vapor pressure, precipitation, relative humidity and mean daily irradiance for the time periods January 1994 to approximately 2100. These data and the VEMAP 1 data (Kittel et al. 1995) were used to drive models in VEMAP Phase 2, the objectives of which are to compare time-dependent ecological responses of biogeochemical and coupled biogeochemical-biogeographical models to historical and projected transient forcings across the conterminous United States.

This data set of daily climate change scenarios was designed to be concatenated with the VEMAP 2: U.S. Daily Climate, 1895-1993 data set to create a single climate series from 1895 to ~2100.

This data set is being made available for the U.S. National Assessment.

Users are requested to confer with the NCAR VEMAP Data Group to ensure that the intended application of the data set is consistent with the generation and limitations of the data.

For more information, refer to the VEMAP homepage.

Data Citation

Cite this data set as follows (data citation revised on December 18, 2002):

Kittel, T.G.F., N.A. Rosenbloom, C. Kaufman, J.A. Royle, C. Daly, H.H. Fisher, W.P. Gibson, S. Aulenbach, R. McKeown, D.S. Schimel, and VEMAP 2 Participants. 2001. VEMAP 2: U.S. Daily Climate Change Scenarios. ORNL DAAC, Oak Ridge, Tennessee, USA.


Johns T. C., R. E. Carnell, J. F. Crossley, J. M. Gregory, J. F. B.Mitchell, C. A. Senior, S. F. B.Tett, and R. A. Wood. 1997. The Second Hadley Centre coupled ocean-atmosphere GCM: Model description, spinup and validation. Climate Dynamics 13:103-134.

Kittel, T. G. F., N. A. Rosenbloom, T. H. Painter, D. S. Schimel, and VEMAP Modeling Participants. 1995. The VEMAP integrated database for modeling United States ecosystem/vegetation sensitivity to climate change. Journal of Biogeography 22:857-862.

Kittel, T. G. F., J. A. Royle, C. Daly, N. A. Rosenbloom, W. P. Gibson, H. H. Fisher, D. S. Schimel, L. M. Berliner, and VEMAP 2 Participants. 1997. A gridded historical (1895-1993) bioclimate dataset for the conterminous United States. Pages 219-222, in: Proceedings of the 10th Conference on Applied Climatology, 20-24 December 1997, Reno, NV. American Meteorological Society, Boston.

Mitchell J. F. B., T. C. Johns, J. M. Gregory, and S. Tett. 1995. Climate response to increasing levels of greenhouse gases and sulphate aerosols. Nature 376:501-504.

VEMAP Members. 1995. Vegetation/Ecosystem Modeling and Analysis Project (VEMAP): Comparing biogeography and biogeochemistry models in a continental-scale study of terrestrial ecosystem responses to climate change and CO2 doubling. Global Biogeochemical Cycles 9:407-437.

Data Format:

This is a gridded data set of daily climate change scenario modeling outputs for the conterminous U.S. Data files are in partial-grid netCDF format; that is, the data are stored in time/lat/lon format representing a partial snapshot of the gridded U.S. (including only non-background values) for each time slice.

For information on companion files as well as Parameter/Variable Names, Variable Description/Definition, Units of Measurement, and Data File Formats see this companion file:

Guides to the netCDF file format (including links to display software and editing tools, e.g., NCOs) can be found at

Document Information:

Document Review Date:

April 20, 2001