Accession Number : AD0409289

Title :   The Energy Budget at the Earth's Surface. Part I. Preliminary Studies at Ithaca, N. Y., 1959.

Corporate Author : AGRICULTURAL RESEARCH SERVICE ITHACA NY

Personal Author(s) : Shinn, Joseph H. ; Stoller, J. H. ; Yocum, Conrad S.

Report Date : MAY 1963

Pagination or Media Count : 33

Abstract : Representative energy balance data over corn and alfalfa fields point up the importance that leaf cover (and thus ''surface wetness'') has in effecting the partition of net radiation. In a cornfield sensible heat exchange in the soil and the air was proportionately greater than in an alfalfa field where more energy was exchanged as latent heat. Energy balance studies in a wintertime snowfield under solar radiation intensities comparable to those in a summertime cornfield reveal how important albedo (solar radiation reflection) is to the energy balance. In an investigation of the surface aerodynamic properties of a cornfield, it was found that the elastic properties of the surface cause the ''roughness length'' to increase with windspeed, and the ''crop displacement'' to decrease with windspeed. This suggests that with increasing windspeed the corn crop surface appears to increase in roughness length, and thus act as a greater momentum sink. (Author)

Descriptors :   (*CLIMATE, RADIATION EFFECTS), (*ALBEDO, SOILS), PHOTOCHEMICAL REACTIONS, ATMOSPHERES, AGRICULTURE, ENERGY, WIND, THERMAL DIFFUSION.

Distribution Statement : APPROVED FOR PUBLIC RELEASE