Clear atmospheric effects on insolation illustrated by broad-band radiometer measurements

Thesis/Dissertation · Sat Jan 01 04:00:00 EST 1983

OSTI ID:5888846

Spencer, D W

Spectral measurements from the Solar Energy Meteorological Research and Training Site - Region II monitoring station - are used to determine some of the effects of the cloudless atmosphere on the surface insolation. The effects illustrated are aerosol scattering and absorption, attenuation by volcanic dust clouds, and water vapor absorption. Parameters determined from the measurements are also compared to the results from a radiative transfer model. The direct and global solar infrared spectrum decreases with increasing dew point. A linear regression between dew point and the direct and global intensities under clear skies resulted in predictive errors less than 10%. The visible portions of the spectrum were not effected. The measured aerosol optical depths were compared to the results of a radiative transfer model. The diffuse-to-direct ratio increased with increasing optical depth in a similar fashion in both the radiative transfer model and measurements. The El Chichon dust cloud reduced the solar direct intensity in late summer of 1982. The effect was most pronounced in the 620-690 nm spectral band, although all bands were reduced. The global intensity was not measurably affected. The Mt. St. Helens dust cloud produced a dramatic insolation reduction over several days, but had no measurable long-term effect.

• OSTI ID: 5888846
• Country of Publication: United States
• Language: English

Related Subjects

500200* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
COOLING
DEW POINT
DUSTS
ENVIRONMENTAL EFFECTS
INFRARED SPECTRA
INSOLATION
MEASURING INSTRUMENTS
MONITORING
PARTICLES
PARTICULATES
RADIATION DETECTORS
RADIATIVE COOLING
RADIOMETERS
SPECTRA
VARIATIONS
VOLCANOES