Estimation of surface heat and moisture fluxes over a prairie grassland 3. Design of a hybrid physical/remote sensing biosphere model

Journal Article · Sat Mar 20 00:00:00 EST 1993 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/92JD01907· OSTI ID:6598260

Smith, E A; Cooper, H J; Hengyi, Weng ^[1]; Crosson, W L ^[2]

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1. Florida State Univ., Tallahassee (United States)
2. Universities Space Research Association, Huntsville, AL (United States)

This is the third in a series of papers describing a measurement program and modeling approach to the estimation of surface heat and moisture fluxes over a tallgrass prairie. The authors describe the design and formulation of an experimental biosphere model (Ex-BATS) which follows the development of Dickinson's biosphere-atmosphere transfer scheme (BATS). Ex-BATS has been designed to incorporate in situ measurements and satellite parameterizations of certain canopy variables which are slowly varying in the course of a growing season. All components of a multistage biosphere process model used to simulate the exchange of heat and moisture between the canopy and the atmosphere are presented here. The remote sensing aspects of the model are described in a companion paper. The procedures used to optimize the model and the validation of the model against First ISLSCP Field Experiment (FIFE) observations taken during 1987 are described. Validation was carried out for three of the four intensive field campaigns (IFC): 1,2 and 3. The validation intercomparison shows that the Ex-BATS model reproduces the diurnal behavior of the surface fluxes very closely. The rms differences between in situ measurements of sensible and latent heat fluxes and their model counterparts are of the order of 35 W m[sup [minus]2]. Biases over the three IFCs, which ranged in duration from 10 to 17 days, are typically less than 20 W m[sup [minus]2]. The overall bias for the 44 days within the first three IFCs is less than 10 W m[sup [minus]2]. The biases and rms differences are of the same order as the accuracy and precision uncertainties of the measured fluxes, therefore the model provides a useful experimental tool to explain radiative, hydrological, and physiological controls on surface fluxes over vegetated canopies and the explicit sources of water flux to the atmosphere from transpiration, foliage evaporation, and soil evaporation. 37 refs., 12 figs., 7 tabs.

• OSTI ID: 6598260
• Journal Information: Journal of Geophysical Research; (United States), Vol. 98:D3; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
54 ENVIRONMENTAL SCIENCES
BIOSPHERE
DESIGN
SIMULATION
RANGELANDS
ENERGY BUDGETS
MOISTURE
REMOTE SENSING
ACCURACY
BEHAVIOR
CANOPIES
DAILY VARIATIONS
EARTH ATMOSPHERE
EVAPORATION
HEAT FLUX
HYDROLOGY
LATENT HEAT STORAGE
SATELLITES
SENSIBLE HEAT STORAGE
TRANSPIRATION
VALIDATION
WATER
WATER VAPOR
ECOSYSTEMS
ENERGY STORAGE
FLUIDS
GASES
HEAT STORAGE
HYDROGEN COMPOUNDS
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
STORAGE
TERRESTRIAL ECOSYSTEMS
TESTING
VAPORS
VARIATIONS
140100* - Solar Energy- Resources & Availability
540110
540210 - Environment
Terrestrial- Basic Studies- (1990-)