Some Observations of Snowfall and Meteorological Conditions in Arctic Canada

Abstract

Observations of snow crystals were made in mid-winter at Inuvik, N.W.T., Canada, in order to study the snow crystal of cold temperature type. The following results were obtained: 1) The cloud temperature was, in general, warmer than expected during the observation period, that is, nearly the same as observed in snow clouds in midlatitudes, although the surface temperature was lowered to ?30 or ?40°C. 2) Regarding the type of snow crystals, Nakaya's Ta-s diagram was well applicable to the snow crystal in Arctic Canada. 3) Almost every day during the observation period, snowfalls were observed; however the fall intensity was as light as 1 or 2 cm day?1. In the case of a moderate snowfall of 5.1 cm day?1, the snowfall was caused by an arctic front at the 850 mb level. The vapor for the snowfall was supplied from the warm surface of the eastern or northern Pacific Ocean. 4) One day, small supercooled raindrops were observed, but no cloud region of temperature warmer than 0°C was detected in the clouds within 1000 km around the observation site. However, rain occurred in between RAOD observation times.