Meridional distribution and seasonal variation of stable oxygen isotope ratio of precipitation in the Southern Ocean

The stable oxygen isotope ratio(δ^<18>O) in precipitation is known to have important meridional and seasonal variations, but there are almost no measurements of δ^<18>O in precipitation over polar oceans. The present research took advantage of 4 opportunities for in situ observations in...

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Bibliographic Details
Main Authors: Kayo Nakamura, Shigeru Aoki, Takenobu Toyota, Yuichi Aoyama
Format: Article in Journal/Newspaper
Language:English
Japanese
Published: National Institute of Polar Research 2010
Subjects:
Online Access:https://doi.org/10.15094/00009534
https://doaj.org/article/290710960ef04b12b6067e79f72d0125
Description
Summary:The stable oxygen isotope ratio(δ^<18>O) in precipitation is known to have important meridional and seasonal variations, but there are almost no measurements of δ^<18>O in precipitation over polar oceans. The present research took advantage of 4 opportunities for in situ observations in summer and winter at high latitudes in the Southern Ocean. In addition, we analyzed samples of precipitation at Syowa Station in 2008 to obtain year-round data. Based on these data, we consider the meridional and seasonal variations of δ^<18>O in precipitation over the Southern Ocean. In general, δ^<18>O decreases with increasing latitude, and is lower in winter than in summer. The latitude gradient is stronger in winter. At 60°S, δ^<18>O is -5.4‰ and -11.3‰ in summer and winter, respectively, while the corresponding figures at 66°S are -10.5‰ and -20.8‰. These results will help us understand the mechanisms of the salinity distribution and its variation in the Antarctic Ocean.