|
Title
|
|
|
|
A computerized numerical experimental study of average solar radiation penetration in plant stands
|
|
|
Author
|
|
|
|
|
|
|
Abstract
|
|
|
|
| An important problem in radiation measurements is the averaging of radiant fluxes in horizontal directions. The use of downward cumulative foliage-areal index averaged over a horizontal surface for the calculation of the average penetration of solar radiation in a plant stand underestimates penetration unless the stand is horizontally uniform. Using a computerised numerical experiment method we show that the underestimation of penetration varies with the downward cumulative foliage-areal index, the extinction coefficient, as well as the foliage distribution pattern. The results show that the underestimation is strongly pronounced for some combinations of extinction coefficient and foliage-areal index. It is also shown that the use of a penetration value averaged over a horizontal surface (P(AP)) to invert the stand foliage-areal index (LAI) by means of the logarithm formula LAI = -ln(P(AP))/k can cause large underestimation of LAI, especially in the case of large LAI. Numerical results are presented in this paper to provide a basis for calibration. |
|
|
|
Language
|
|
|
|
English
|
|
|
Source (journal)
|
|
|
|
Journal of quantitative spectroscopy and radiative transfer. - Oxford
|
|
|
Publication
|
|
|
|
Oxford
:
1993
|
|
|
ISSN
|
|
|
|
0022-4073
|
|
|
DOI
|
|
|
|
10.1016/0022-4073(93)90008-6
|
|
|
Volume/pages
|
|
|
|
49
:6
(1993)
, p. 651-658
|
|
|
ISI
|
|
|
|
A1993LG39800007
|
|
|
Full text (Publisher's DOI)
|
|
|
|
|
|
|
Full text (publisher's version - intranet only)
|
|
|
|
|
|