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SEASONAL VARIATION OF SOLAR UV‐RADIATION AT A HIGH MOUNTAIN STATION
Author(s) -
Blumthaler M.,
Ambach W.,
Canaval H.
Publication year - 1985
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1985.tb01553.x
Subject(s) - noon , equinox , ozone , atmospheric sciences , radiation , environmental science , sunburn , diurnal temperature variation , seasonality , ozone layer , chemistry , meteorology , physics , biology , optics , latitude , ecology , astronomy
— At the high mountain station Jungfraujoch (3576 m), the maximum daily totals for erythemal dose (G ER ), UV‐A radiation (G UVA ) and global radiation (G) are 29 Sunburn Units d −1 , l.7 MJ m −2 d −1 and 37 MJ m −2 d −1 . The maximum instantaneous values at solar noon in midsummer are 4.2 Sunburn Unit h −1 , 53 W m −2 and 1110 W m −2 . A significantly nonlinear relation between G ER and G results from the influence of the irradiated ozone mass on the UV‐B erythemal dose. In contrast, G UVA and G are linearly proportional, which can be seen from the diurnal and seasonal courses of the ratios G ER /G and G UV A/G AND from their dependence on the optical air mass. UV‐A radiation flux is less attenuated by cloudiness than is global radiation. This effect is masked for the erythemal dose by variations in the ozone concentration. Due to seasonal ozone layer thickness and effective pathlength variations, the ratio G ER /G shows a significant asymmetry. At the autumn equinox it is about 16% higher than at the spring equinox.