The beautiful waters at Lake Tahoe are clear and blue, but that is dependent on different things along with different environmental factors which determine how clear the blue lake is at any given time.
But those are different things, with different environmental factors coming into play to determine how clear and how blue the lake is at any given time.
That is one outcome of new research into the unique characteristics of Tahoe that the scientists released on Thursday with important management implications for the landmark alpine lake.
As experts pursued costly efforts for years in order to revert the loss of the lake’s famed clarity, it was assumed that the stunning blue color and clarity of Tahoe were generally synonymous.
“We just always thought clarity meant blueness,” said Geoffrey Schladow, director of the UC Davis Tahoe Environmental Research Center, which Thursday released the 2015 State of the Lake Report.
“Blueness is one of the iconic values of Lake Tahoe and I think we were always assuming blueness equates to clarity,” Schladow said.
The assumption’s been thrown on its head with UC Davis scientist Shohei Watanabe conducting research in collaboration with researchers from NASA’s Jet Propulsion Laboratory and Canada’s Laval University.
The scientists worked to find out the blueness of the lake continuously from a research buoy floating in the middle of the lake. Devices such as hyperspectral radiometers measured the amount of light leaving the lake at each wavelength – essentially, the color which a person could see, would develop a ‘blueness index’ for Tahoe.
When the results were combined with other measurements taken to determine the clarity of the lake, something surprising was discovered – blueness and clarity are not actually similar but vary opposite. At times of the year when clarity tends to increase and one can see deeper into Tahoe’s depths, the rich blue color of the water tends to decrease.