Snowfall and oxygen-isotope variations off the north coast of Ellesmere Island

• Main Author: O. Jeffries
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1987
• Subjects: Arctic; Arctic Ocean; Ellesmere Island
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.464.6553; http://www.igsoc.org:8080/journal/33/114/igs_journal_vol33_issue114_pg195-199.pdf

ABSTRACT. Snow-pack along the land-fast ice fringe off the north coast of Ellesmere Island was generally characterized by depth-hoar overlain by dense snow and wind slab. Mean snow depth in the study area was 0.54 m (1982-85) and the mean S180 value of the snow-pack was-31.30 / 00. Isotope data were not obtained previously for this geographic region and, therefore, complement a previous study of S180 variations in High Arctic snow (Koerner, 1979). The data are consistent with an Arctic Ocean moisture source. The S180 profiles show seasonal variations, with winter snow being more depleted in 180 than fall and spring snow. However, the S180 profiles are dominated by a trend to higher S180 values with increasing depth. This is attributed to a decrease in S180 values as condensation temperatures fall during the autumn-winter accumulation period. During this time, there is also a change from relatively open to almost complete ice cover in the Arctic Ocean. The change in evaporation conditions and consequent effect on S values gives rise to a sharp discontinuity in the S180 profiles and a bi-modal S180 frequency distribution. The bi-modal distribution is reinforced by a secondary isotope fractionation that occurs during depth-hoar formation. This isotope effect leads to a wider S180 range but does not significantly alter the mean S180 value.