An analysis of infrared temperature observations over wheat and calculation of latent heat flux

• Published in: Agricultural and forest meteorology Vol. 37; no. 1; pp. 75 - 88
• Main Authors: Choudhury, B.J., Reginato, R.J., Idso, S.B.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.05.1986; Oxford Elsevier; New York, NY
• Subjects: Agricultural and forest climatology and meteorology. Irrigation. Drainage; Agricultural and forest meteorology; Agronomy. Soil science and plant productions; Biological and medical sciences; Crop climate. Energy and radiation balances; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Monocotyledones; United States; Heat flow; North America; Cereal crop; Energy balance; Gramineae; Air temperature; America; Angiospermae; Evapotranspiration; Heat balance; Spermatophyta; Plant cover; Arizona; Triticum aestivum; Phytoclimate
• ISSN: 0168-1923; 1873-2240
• DOI: 10.1016/0168-1923(86)90029-8

From half-hourly averaged observations of net radiation, latent and soil heat fluxes over wheat, the sensible heat flux is calculated as the residual component of the surface energy balance. Then, the aerodynamic surface temperature is obtained by solving iteratively the aerodynamic equation for sensible heat flux, taking into consideration the bluffbody (differences in roughness height for heat and momentum exchange) and the stability (differences in surface and air temperatures) corrections to the aerodynamic resistance. The aerodynamic temperatures are found to be lower (higher) than the infrared thermometric observations under stable (unstable) atmospheric conditions. However, when the infrared temperatures were used in a resistance-energy balance equation to estimate the latent heat flux, then the estimated fluxes showed a high linear correlation ( r = 0.96) and a moderate standard error (47 W m −2) under regression analysis with the observed fluxes.