Specifying land surface characteristics in general circulation models: Soil profile data set and derived water‐holding capacities

Abstract

A standardized global data set of soil horizon thicknesses and textures (particle size distributions) has been compiled from the Food and Agriculture Organization of the United Nations/United Nations Educational, Scientific, and Cultural Organization (FAO/UNESCO) Soil Map of the World, Vols. 2–10 [1971–1981]. This data set was developed for use by the improved land‐surface hydrology parameterization designed by Abramopoulos et al. [1988] for the Goddard Institute for Space Studies General Circulation Model II (GISS GCM). The data set specifies the top and bottom depths and the percent abundance of sand, silt, and clay of individual soil horizons in each of the 106 soil types cataloged for nine continental divisions. When combined with the World Soil Data File [Zobler, 1986], the result is a l°×l° global data set of variations in physical properties throughout the soil profile. These properties are important in the determination of water storage in individual soil horizons and exchange of water with the lower atmosphere within global climate models. We have used these data sets, in conjunction with the Matthews [1983] global vegetation data set and texture‐based estimates of available soil moisture, to calculate the global distributions of soil profile thickness, potential storage of water in the soil profile, potential storage of water in the root zone, and potential storage of water derived from soil texture. Comparisons with the water‐holding capacities used in the GISS Model II show that our derived values for potential storage of water are consistently larger than those previously used in the GISS GCM. Preliminary analyses suggest that incorporation of this data set into the GISS GCM has improved the model's performance by including more realistic variability in land surface properties.

Westerly jet stream and past millennium climate change in Arid Central Asia simulated by COSMO-CLM model

“…Dai-PDSI is calculated from the Climate Research Unit (CRU) monthly surface air temperature (Jones et al 2001) and precipitation data from National Centers for Environmental Prediction (NCEP). The soil texture-based water-holding-capacity map from Webb et al (1993) is applied as available water capacity (AWC) in the Dai-PDSI calculation.…”

Evaluation of a present-day climate simulation with a new coupled atmosphere-ocean model GENMOM

“…At T31 horizontal resolution the Bering Strait is closed. Modern values for the distribution of vegetation (Dorman and Sellers, 1989), soil texture (Webb et al, 1993) and freshwater lakes (Cogley, 1991) are prescribed. The use of ICE-4G orography to derive global topography, bathymetry, and ice-sheet extent is based on our goal of streamlining the configuration of GENMOM for paleoclimate applications.…”

Simulating multiyear drought events in North America with the HadCM3 climate model

“…This was computed using surface temperature and precipitation data from the 0.5° gridded CRU TS 2.1 datasets (Mitchell et al, 2005), and 1° gridded soil water-holding capacity data (Webb et al, 1993). The model used in the study is the UKMO HadCM3 ocean-atmosphere GCM (Gordon et al, 2000), due to its relative success at simulating ENSO variability (Guilyardi, 2005;Joseph and Nigam, 2006), one of the main drivers of North American drought variability.…”

“…Known natural forcings, including volcanic aerosols, orbital and solar forcings, are included for the duration of the model run, while anthropogenic forcings, including well-mixed greenhouse gases, aerosols, land-surface changes and ozone are included from 1750 (Tett et al, 2007). Surface temperature and precipitation data from the model, and soil water-holding capacity data from Webb et al (1993) were used in the calculation of the model scPDSI. Figure 1 shows the DAI time series for the mean summer (JJA) observed and model scPDSI.…”