  The attenuation coefficient of 532 nm light in water under different
atmospheric conditions was investigated. Measurements were made over a two-year
period at the same location and show that the attenuation coefficient is
significantly influenced by the atmospheric environment. It is lowest when the
atmospheric pressure is high and temperature is low, and is highest when the
atmospheric pressure is low and temperature is high. The maximum attenuation
coefficient of pure water in these studies was about three times the minimum
value. The mechanism of the phenomena is discussed. These results are also
important in underwater acoustics.
