Simplified techniques to study components of solar radiation under haze and clouds

Journal Article · Mon Mar 01 00:00:00 EST 1982 · J. Appl. Meteorol.; (United States)

DOI:https://doi.org/10.1175/1520-0450(1982)021<0373:STTSCO>2.0.CO;2· OSTI ID:6460437

Wesely, M L

Estimates of the global (G), diffuse (D) and direct-beam (I) irradiances at the surface of the earth can be obtained with a single instrument, the ''dial'' radiometer. The dial assembly intermittently shades a solid-state sensor on a continual automatic basis. This is a very simple instrument that does not require mechanical adjustments of the shade. When corrections for imperfect cosine response and excessive shading of sky radiation are performed, measurements averaged over 1 h should be accurate well within +/- 5%. Estimates of atmospheric turbidity or haziness can be expressed as an extinction coefficient, computed for I in reference to that obtained under cloudless clean skies for the same solar zenith angle. The uneven spectral response of silicon-cell and PAR (photosynthetically active radiation) sensors should be considered when comparing estimates of G, D or I to measurements of these components by a wide-band sensor. Linear relationships seem adequate for a variety of cloud conditions. This allows the use of a single dial silicon-cell radiometer, for example, to estimate quite accurately the values of G, D and I that would be seen by wide-band PAR radiometers. An alternative, but less exact, means of obtaining estimates of hourly averages of D and I is to measure only G and use the ratio of G to that which would be obtained under clean, cloudless conditions as the sole determining factor.

• Research Organization: Argonne National Lab., IL
• OSTI ID: 6460437
• Journal Information: J. Appl. Meteorol.; (United States), Vol. 21:3
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
DIFFUSE SOLAR RADIATION
MEASURING METHODS
DIRECT SOLAR RADIATION
RADIOMETERS
DESIGN
ACCURACY
SOLAR EQUIPMENT
EQUIPMENT
MEASURING INSTRUMENTS
RADIATION DETECTORS
RADIATIONS
SOLAR FLUX
SOLAR RADIATION
STELLAR RADIATION
140100* - Solar Energy- Resources &amp; Availability
440105 - Radiation Instrumentation- Radiometric Instruments- (-1987)