Ultraviolet Radiation and Bio-optics in Crater Lake, Oregon, 2005
Long-term Trends and Possible Impacts of Future Climate Change
Our comparisons of nearly-continuous annual summer optical data since 1978 suggest that UV transparency changes on decadal and longer cycles, perhaps in response to a combination of rain and stratospheric ozone influencing the phytoplankton community, with heavy summer rain occasionally influencing the level of suspended mineral particles. We also cannot rule out the impact of trophic interactions and nutrient upwelling as additional factors influencing phytoplankton and UV transparency. The sparse attenuation estimates from proxy data between 1896 and 1978 fall within the range of the better characterized period since 1978, and from these we infer that there has been no long-term change in UV transparency since 1896.