Isotopic mass fractionation of snow due to depth hoar formation

• Main Authors: ハチクボ アキヒロ, ハシモト シゲマサ, ナカオ マサヨシ, ニシムラ コウイチ, Akihiro Hachikubo, Shigemasa Hashimoto, Masayoshi Nakawo, Kouichi Nishimura
• Format: Report
• Language: English
• Published: Scientific Paper 2000
• Subjects: Polar meteorology and glaciology
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2907; http://id.nii.ac.jp/1291/00002907/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2907&item_no=1&attribute_id=18&file_no=1

To clarify the isotopic changes (δD and δ^<18>O) of snow due to depth hoar formation, large temperature gradients were imposed on snow samples using a closed and insulated box for several days. δD and δ^<18>O increased in the high temperature region where sublimation enriched heavy H_2O, and decreased in the low temperature region where light H_2O was concentrated. Isotope diagrams of the data showed slopes of 2.4-4.9,which indicated that isotopic fractionation on sublimation depends on the kinetic isotope effect. It was also suggested that the transfer coefficient of water vapor in snow increases slightly due to convection; and the changes of isotopic profiles depend primary on the snow density as it affects permeability to vapor diffusion.