Solar Ultraviolet Radiation at the Earth's Surface

Abstract

The biologically effective ultraviolet irradiance at the earth's surface varies with the elevation of the sun, the atmospheric ozone amount, and with the abundance of scatterers and absorbers of natural and anthropogenic origin. Taken alone, the reported decrease in column ozone over the Northern Hemisphere between 1969 and 1986 implies an increase in erythemal irradiance at the ground of four percent or less during summer. However, an increase in tropospheric absorption, arising from polluting gases or particulates over localized areas, could more than offset the predicted enhancement in radiation. Any such extra absorption is likely to be highly regional in nature and does not imply that a decrease in erythemal radiation has occurred on a global basis. The Antarctic ‘ozone hole’ represents a special case in which a portion of the earth has experienced ultraviolet radiation levels during spring that are far in excess of those which prevailed prior to the present decade.

Basal and squamous cell carcinoma risks for golfers: An assessment of the influence of tee time for latitudes in the Northern and Southern hemispheres

“…Considering a cloud free sky, in which the UV irradiance follows a normal distribution with the time of day, exposures received before and after solar noon will be lower than exposures received during the peak noon period, followed by irradiance reductions caused by absorption by stratospheric ozone, air and atmospheric particulates, the local altitude and slight variations in the earth sun distance caused by the earth's elliptical solar orbit (14,15,16,17). The timing and total duration of any playing round has the most significant influence on the total UV exposure received.…”

Testing Adaptive Plasticity to Uv: Costs and Benefits of Stem Elongation and Light-Induced Phenolics

“…Black mangrove trees were selected for this study for several reasons. First, as inhabitants of the tropics, black mangroves receive higher levels of UV radiation than plants inhabiting temperate regions (Frederick et al, 1989;Madronich, 1993). Moreover, this species inhabits coastlines and is rarely shaded by taller trees.…”

Assessment of the exposure to biologically effective UV radiation using a dosimetric technique to evaluate the solar spectrum

“…The reduction in the absorption of solar UV by ozone is of significant concern because of the concomitant increase in terrestrial UV. The waveband 280 nm to 320 nm (UVB) is that most strongly affected by changes in stratospheric ozone concentration (Frederick et al, 1989). The irradiance at the earth's surface for wavelengths shorter than 280 nm (UVC) is insignificant because of the very high absorption not only by the remaining ozone but by other atmospheric constituents.…”