New Data on the Tendency and Causes of Deuterium Excess Variations during One Snowfall

摘要

The aim of the present work is to trace the trend of change of isotopic composition (δ~(18)O and δD) in fresh snow cover from a unified air mass along the transect of about 1400 km long in the north of the European part of Russia: from Konosha station (61°01′ N, 40° 10′ E), through Inta-Seida station, to Eletskaya station in the piedmont of the Polar Urals (67°02′ N, 64°13′ E). Another aim was to explain variations in d_(exc) in this snow cover. On the night from December 22 to 23, 2003, during northeastward movement of the atmospheric front, an intensive snowfall began at the distance of about 400 km northeast of Moscow and lasted until December 25. We sampled snow for isotope analysis every 3— 7 h along the profile from Konosha station to Pol-yarnyi station. We went by train, following the direction of the atmospheric front, at a speed of about 60 km/h (about 1400-1500 km/day). When sampling, we recorded the approximate near-surface air temperature (Fig. 1a) which was then specified using the GISMETEO meteorological server based on the measurements at the nearest stations.