Aircraft- and tower-based fluxes of carbon dioxide, latent, and sensible heat
- Agriculture Canada, Centre for Land and Biological Resources Research, Ottawa (Canada) Argonne National Lab., IL (United States) National Research Council of Canada, Flight Research Lab., Ottawa (Canada) McGill Univ., Sainte-Anne-de-Bellevue (Canada) Nebraska Univ., Lincoln (United States)
Fluxes of carbon dioxide, water vapor, and sensible heat obtained over a grassland ecosystem, during the First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE), using an aircraft- and two tower-based systems are compared for several days in 1987 and in 1989. The tower-based cospectral estimates of CO2, sensible heat, water vapor, and momentum, expressed as a function of wavenumber K times sampling height z, are relatively similar to the aircraft-based estimates for K x z greater than 0.1. A measurable contribution to the fluxes is observed by tower-based systems at K x z less than 0.01 but not by the aircraft-based system operating at an altitude of approximately 100 m over a 15 x 15 km area. Using all available simultaneous aircraft and tower data, flux estimates by both systems were shown to be highly correlated. As expected from the spatial variations of the greenness index, surface extrapolation of airborne flux estimates tended to lie between those of the two tower sites. The average fluxes obtained, on July 11, 1987, and August 4, 1989, by flying a grid pattern over the FIFE site agreed with the two tower data sets for CO2, but sensible and latent heat were smaller than those obtained by the tower-based systems. However, in general, except for a small underestimation due to the long wavelength contributions and due to flux divergence with height, the differences between the aircraft- and tower-based surface estimates of fluxes appear to be mainly attributable to differences in footprint, that is, differences in the area contributing to the surface flux estimates. 21 refs.
- Research Organization:
- National Aeronautics and Space Administration, Greenbelt, MD (United States). Goddard Space Flight Center
- OSTI ID:
- 6295459
- Journal Information:
- Journal of Geophysical Research; (United States), Vol. 97:D17; ISSN 0148-0227
- Country of Publication:
- United States
- Language:
- English
Similar Records
A comparison of surface sensible and latent heat fluxes from aircraft and surface measurements in FIFE 1987
Radiation fluxes at the FIFE site. Final report, 1 January 1991-31 July 1992
Related Subjects
CARBON DIOXIDE
ECOLOGICAL CONCENTRATION
SPATIAL DISTRIBUTION
HEAT FLUX
AERIAL MONITORING
BIOSPHERE
RANGELANDS
SATELLITES
WATER VAPOR
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
DISTRIBUTION
ECOSYSTEMS
FLUIDS
GASES
MONITORING
OXIDES
OXYGEN COMPOUNDS
TERRESTRIAL ECOSYSTEMS
VAPORS
540120* - Environment
Atmospheric- Chemicals Monitoring & Transport- (1990-)