CS36 Ultraviolet Radiation
Date: Friday, June 14, 2002
Time: 8:30:00 AM
Location: Sidney
 
DiepNK, University of Waterloo, Waterloo, Canada, nkdiep@hotmail.com
Smith, R, E, University of Waterloo, Waterloo, Canada, rsmith@sciborg.uwaterloo.ca
 
THE ULTRA-VIOLET RADIATION (UVR) CLIMATE IN THE EASTERN BASIN OF LAKE ERIE
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Increasing levels of ultra-violet radiation (UVR) is of great concern to the aquatic ecosystem, for UVR is known to induce both photobiological and photochemical changes. It is thus important to examine the degree of UVR penetration into the water column. Our objective is to characterize the underwater UVR climate in the eastern basin of Lake Erie and to test existing models for UVR attenuation and possibly to arrive at an improved empirical model for the prediction of UVR attenuation. An intensive spatial survey of Lake Erie east basin was conducted from May-August (2001), which included two transects from the littoral to pelagic. Underwater irradiance profiles were acquired using the Satlantic, a submersible spectroradiometer, to derive estimates of the vertical attenuation coefficients (Kd). Concurrent water samples were collected for measurements of variables thought to affect UVR attenuation including DOC concentration, DOC absorbance, DOC fluorescence, DOC fluorescence excitation-emission spectra (FEES), chlorophyll concentration, ash-free dry weight (AFDW), and particle concentration and size distribution. We expect to identify the factors controlling the attenuation of UVR.