APPLICATION OF COSMIC-RAY NEUTRON MEASUREMENTS TO THE DETERMINATION OF THE SNOW-WATER EQUIVALENT

Application of the water absorption character of cosmic-ray neutrons to the determination of the water equivalent depth of a snow cover is shown. We call this device the cosmic-ray snow gauge. The attenuation curves of the cosmic-ray snow gauge set under or in water or snow are experimentally obtained. Continuous field observations of the snow depths during four snow seasons demonstrate the effectiveness of the present device even for a snow cover of more than 1 m water equivalent, where the relative accuracy is found to be a few percent of the water depth. Possible effects of primary cosmic rays, barometric pressure and water content of soil upon the determination of snow depths are discussed. © 1979.