Premium
Influence of volcanic sulfur dioxide on spectral UV irradiance as measured by Brewer Spectrophotometers
Author(s) -
Fioletov Vitali E.,
Griffioen Erik,
Kerr James B.,
Wardle David I.,
Uchino Osamu
Publication year - 1998
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/98gl51305
Subject(s) - irradiance , volcano , observatory , environmental science , sulfur dioxide , atmospheric sciences , absorption (acoustics) , sulfur , chemistry , geology , physics , optics , astrophysics , inorganic chemistry , organic chemistry , seismology
Spectra of UV irradiance measured by Brewer spectrophotometers at 13 stations in Japan and Canada have been examined to determine the effect of absorption by sulfur dioxide (SO 2 ). A simple algorithm to estimate the total column amount of SO 2 from global UV irradiance measurements has been developed. The algorithm which overestimates SO 2 amounts at low altitudes is useful for identifying large SO 2 absorption and for establishing upper limits of the SO 2 values. Except at one station, the overall occurrence of days with SO 2 amounts greater than 10 Dobson Units (DU) was about 0.22%. The exception was the Kagoshima observatory located 10 km from the volcano, Sakurajima. Volcanic activity resulted in frequent observation of column SO 2 amounts of more than 20 DU over Kagoshima and in extreme cases up to 100 DU. The reduction in the long‐term erythemally weighted UV irradiation due to absorption by SO 2 is between one and two percent at Kagoshima and negligible at the twelve other stations.