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Temporal and spatial variation in solar radiation and photo‐enhanced toxicity risks of spilled oil in Prince William Sound, Alaska, USA
Author(s) -
Barron Mace G.,
Vivian Deborah,
Yee Susan H.,
Diamond Steve A.
Publication year - 2008
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1897/07-317.1
Subject(s) - environmental science , irradiance , solstice , atmospheric sciences , attenuation , solar irradiance , spatial variability , downwelling , seasonality , meltwater , meteorology , oceanography , geology , optics , snow , geography , ecology , physics , latitude , statistics , mathematics , geodesy , upwelling , biology
Solar irradiance (W/m 2 ) and downwelling diffuse attenuation coefficients ( K d ; 1/m) were determined in several locations in Prince William Sound (AK, USA) between April 2003 and December 2005 to assess temporal and spatial variation in solar radiation and the risks of photo‐enhanced toxicity from spilled oil. Weekly irradiance measurements of surface visible light, ultraviolet B (UVB), and ultraviolet A (UVA) radiation in Valdez (AK, USA) followed expected trends of maximum solar irradiance at each summer solstice and minimum values at each winter solstice. Variation from weekly maximum expected surface irradiances was attributed to large variations in environmental conditions over the 142‐week monitoring period. Season and proximity to glacial meltwater were significant determinants of K d , with 1% attenuation depths ranging from 0.4 to 15 m (UVB and UVA) and from 0.5 to 28 m (visible light). The probability of photo‐enhanced toxicity risks estimated from UVA dosimetry decreased with increasing water depth, with higher risks during spring and summer and lower risks during fall and winter. These results demonstrate substantial temporal and spatial variation in solar radiation in Prince William Sound and the potential for significant season‐ and location‐specific photo‐enhanced toxicity risks from spilled oil.