Comparison of Momentum and Energy Balance Methods of Computing Vertical Transfer Within a Crop

Wright, J.L. and Brown, K.W. (1967) Comparison of Momentum and Energy Balance Methods of Computing Vertical Transfer Within a Crop. Agronomy Journal. 59(5):427-432.

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Abstract

Measurements of windspeed, air temperature, wet-bulb
depression, and net radiation were made at several levels
within and above the crop. Soil heat flux and incident
radiation were also measured. Transfer coefficient distributions
were computed separately from the windspeed
data by a momentum balance approach, and from the
other data by the energy balance method. The agreement
between the two methods was better near the top of the
crop than near the soil. Drag coefficients computed from
the energy balance results were not independent of height
within the crop as was assumed in the momentum balance
analysis. The low Reynolds numbers for the lower portion
of the crop could account for the deviation. The
energy balance approach required more measurements but
was easier to apply in calculating the distribution of the
transfer coefficient for the computation of the vertical flux
of such entities as heat, water vapor, and carbon dioxide
within the crop.

Item Type:	Article
NWISRL Publication Number:	0030
Subjects:	Research methodology Mass Import - autoclassified (may be erroneous)
Depositing User:	Dan Stieneke
Date Deposited:	20 Nov 2010 21:51
Last Modified:	15 Feb 2017 22:58
Item ID:	273
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/273