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The land surface parameterization used with the community climate model (CCM3) and the climate system model (CSM1), the National Center for Atmospheric Research land surface model (NCAR LSM1), has been modified as part of the development of the next version of these climate models. This new model is known as the community land model (CLM2). In CLM2, the(More)
Several multi-decadal simulations have been carried out with the new version of the CCSM climate model. This paper reports an analysis of the land component of these simulations. Global annual averages over land appear to be within the uncertainty of observational data sets but the seasonal cycle over land of temperature and precipitation appear too weak.(More)
The Common Land Model (CLM), which results from a 3-yr joint effort among seven land modeling groups, has been coupled with the National Center for Atmospheric Research (NCAR) Community Climate Model (CCM3). Two 15-yr simulations of CCM3 coupled with CLM and the NCAR Land Surface Model (LSM), respectively, are used to document the relative impact of CLM(More)
[1] We present here a simple and robust framework for quantifying the effective sensor depth of cosmic ray soil moisture neutron probes such that reliable water fluxes may be computed from a time series of cosmic ray soil moisture. In particular, we describe how the neutron signal depends on three near-surface hydrogen sources: surface water, soil moisture,(More)
AUGUST 2003 AMERICAN METEOROLOGICAL SOCIETY | C limate and weather forecasting models require the energy, water, and momentum fluxes across the land–atmosphere interface to be specified. Various land surface parameterizations (LSPs), ranging from the simple bucket-type LSP in the 1960s to the current soil–vegetation–atmosphere interactive LSP, have been(More)
1 NCAR Earth System Laboratory, Climate and Global Dynamics Division, National Center for Atmospheric Research, Boulder, CO, USA 2 Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, MI, USA 3 Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA 4 Department of Atmospheric Sciences,(More)
In this study the utility of satellite-based leaf area index (LAI) data in improving the simulation of nearsurface climate with the NCAR Community Climate Model, version 3 (CCM3), GCM is evaluated. The use of mean LAI values, obtained from the Advanced Very High Resolution Radiometer Pathfinder data for the 1980s, leads to notable warming and decreased(More)
[1] The analysis of a global data set of monthly leaf area index (LAI), derived from satellite observations of normalized difference vegetation index (NDVI) for the period July 1981 to September 1994, is discussed in this paper. Validation of this retroactive, coarse resolution (8 km) global multiyear data set is a challenging task because repetitive ground(More)
[1] In semi-arid areas, multiple equilibrium states of an ecosystem (e.g., grassland and desert) are found to coexist, and the transition from grassland to desert is often abrupt at the boundary. A simple ecosystem model is developed to provide the biophysical explanation of this phenomenon. The model has three variables: living biomass, wilted biomass, and(More)