Lake Tahoe is famous for its clear blue waters — but new research suggests that clarity may come with a catch. A study from the UC Davis Tahoe Environmental Research Center, published in the Association for the Sciences of Limnology and Oceanography, shows that ultraviolet radiation in Lake Tahoe can vary by up to 100 times between wet and dry years. The findings are based on 18 years of underwater data through 2023 and highlight how climate-driven weather swings — especially between drought and heavy precipitation — are changing the light that reaches beneath the surface, according to a release from the University of California, Davis. The data shows that during dry years, clearer water allows ultraviolet rays to reach far deeper into the lake. … That shift has big implications: UV radiation influences the lake’s carbon cycle, affects aquatic organisms like zooplankton and fish and can suppress photosynthesis, the foundation of the lake’s food web.