NON-MASS DEPENDENT OXYGEN ISOTOPE EFFECT OBSERVED IN WATER VAPOUR FROM ALERT, CANADA

摘要

Twenty-six precipitation samples from Chicago, IL and northwest part of Indianawere collected from 2003 to 2005. Twenty-five water vapour samples were collected atAlert, Canada (82.5°N, 62.3°W) from 2002 to 2005 by Environment Canada. Seven icecore samples from Dasuopu glacier, Chinese Himalayas (28.2°N, 85.4°E) were drilledby Lonnie G. Thompson and prepared by Mary E. Davis. Sample of Standard LightAntarctic Precipitation (SLAP) is available in the laboratory. Water samples werereacted with bromine pentafluoride to produce oxygen, which was then purified andmeasured by Delta E gas source mass spectrometer. Oxygen isotopic compositions arereported in delta notations and relative to VSMOW. A λ MDF (H2 O) = 0.5292 ± 0.0031(2 σ ) is determined from three-isotope plot of local precipitation samples. No oxygenisotopic anomaly is found in ice core samples from Dasuopu glacier, Chinese Himalayas.Δ 17 O of 0.076 ± 0.075‰ (2 σ ) is observed in water vapour from Alert, Canada. Standard