Evaluation of the importance of Lagrangian canopy turbulence formulations in a soil–plant–atmosphere model
The suitability of using K-theory to describe turbulent transfer within plant canopies was evaluated with field measurements and simulations of a detailed soil–plant–atmosphere model (Cupid). Simulated results with both K-theory and an analytical Lagrangian theory (L-theory) implemented in Cupid wer...
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Veröffentlicht in: | Agricultural and forest meteorology 2003-02, Vol.115 (1), p.51-69 |
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Format: | Artikel |
Sprache: | eng |
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Zusammenfassung: | The suitability of using K-theory to describe turbulent transfer within plant canopies was evaluated with field measurements and simulations of a detailed soil–plant–atmosphere model (Cupid). Simulated results with both K-theory and an analytical Lagrangian theory (L-theory) implemented in Cupid were evaluated against Bowen-ratio energy balance measurements and the temperature profiles in potato canopies. There was no difference between K- and L-theory in terms of simulating
E,
H and CO
2 fluxes over the canopy. The model slightly underestimated measured
E by 3–8%; the comparison of
H contained much scatter and the model slightly overestimated CO
2 flux. When the model was tested by simulating temperature and vapor pressure profiles within the canopy, the difference between the K- and L-theory was much smaller than the difference between each theory and the measurements. From simulated temperature profiles, the near-field correction provided by using L-theory seemed to be significant in canopies where the foliage is concentrated in the upper part, but appeared unnecessary for foliage distributed throughout the canopy depth. The major difference between K- and L-theory was in simulations of canopy radiometric temperature; with foliage distributed through out the depth of the canopy, K-theory consistently predicted higher canopy radiometric temperatures than L-theory by 2–8
°C, depending on leaf area index. More systematic study is required to determine if K-theory or L-theory is inadequate for remote sensing of radiometric temperature of canopies. |
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ISSN: | 0168-1923 1873-2240 |
DOI: | 10.1016/S0168-1923(02)00167-3 |