AIRBORNE SNOW CONCENTRATION AND VISIBILITY

Little information is available on the probability distribution of the mass concentration of snow in the atmosphere. Such a deficiency became apparent as the result of engine malfunctions in helicopters while flying in falling snow. To help rectify this deficiency and so provide data for the meaningful design and testing of aircraft engine intake systems for operation in snow, a program was initiated to measure the snow mass content of the air. In conjunction with the measurements of snow concentration various other meteorological parameters were measured. It was found that the snow concentration may be estimated from the visibility with reasonable accuracy, thus offering the hope that concentration statistics may be derived for any location where climatological data on visibility are available. This is currently being tested using climatological data for Ottawa. /Author/