Stable oxygen isotope ratio observed in the precipitation at Ny-Alesund, Svalbard (scientific note)

• Main Authors: Makoto Igarashi, Kokichi Kamiyama, Okitsugu Watanabe
• Format: Report
• Language: English
• Published: National Institute of Polar Research 2001
• Subjects: Ny-Ålesund; Svalbard; ice core; Memoirs of National Institute of Polar Research; Ny Ålesund; Polar Research
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2372; http://id.nii.ac.jp/1291/00002372/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2372&item_no=1&attribute_id=18&file_no=1

The stable oxygen isotope ratio (δ^<18>O) in ice cores and surface snow pits samples obtained in Svalbard does not show a seasonal variation clearly. In preceding research, it has been reported that δ^<18>O is change by melting of the snow layer. However, to what degree δ^<18>O in snow changes after accumulation is not clear. We carried out the observation in Ny-Ålesund, northwestern part of Svalbard, in the 1993/94 winter season and 1994 summer season in order to investigate the initial values of δ^<18>O in precipitations. Values of δ^<18>O both in winter and summer were almost same (-4∿-24‰) as well as the average of each season was also almost same (-12.9‰, -12.3‰), which shows that δ^<18>O in precipitations does not have a clear seasonal variation. It is known that the value of δ^<18>O in precipitation changes by the condensation temperature of water vapor. Temperature, at the height where the wettest air mass existed over northwestern Svalbard, changed almost same range in winter and summer, when the rain fell at Ny-Ålesund. And, there was a better correlation between δ^<18>O in precipitation and temperature of moist air masses than δ^<18>O in precipitation and air temperature at the observation site both in winter and in summer. Therefore, fluctuation of δ^<18>O seemed to show the almost equal, even if the season was different. This fact can be regarded that one of the reasons why δ^<18>O of ice core drilled in Svalbard does not show the seasonal variation clearly.