昭和基地における降雪・飛雪の電気伝導度

• Main Authors: 長田 和雄, 原 圭一郎, 矢吹 正教, 安達 正樹, Kazuo Osada, Keiichiro Hara, Masanori Yabuki, Masaki Adachi
• Format: Report
• Language: Japanese
• Published: 名古屋大学大学院環境学研究科 2010
• Subjects: 551.5; Kita-no-ura; Syowa Station; Ura; Sea ice
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=9580; http://id.nii.ac.jp/1291/00009580/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=9580&item_no=1&attribute_id=18&file_no=1

昭和基地で2003-2006年にかけてドリフトや降雪,飛雪のサンプリングをおこない,雪試料の融解水の電気伝導度を測定した.その結果,弱風時にしんしんと降る降雪の電気伝導度は,季節に関係なく数十 μS cm以下の低い値を示したのに対し,強風時の飛雪の電気伝導度は4-7月に数百～ 数千 μS cm前後と高く,9月以後には数百 μS cmと低くなる季節変化を示した.昭和基地の風上にあたる北の浦での海氷上積雪量の季節変化と比較検討したところ,風上の海氷が流出すると飛雪の電気伝導度が高くなり,逆に,風上の海氷上に雪が積もると飛雪の電気伝導度が下がることがわかった.これは,飛雪の電気伝導度が海氷からのブラインの影響を強く受けるためだと考えられる. Samples of fallen snow, drifting snow and deposited snow were obtained at Syowa Station from April 2003 to October 2006. Electroconductivity of the meltwater was measured. The electroconductivities of the samples for the fallen snow under weak wind condition were mostly below several tens of μS cm, whereas much higher values were obtained for the drifting snow samples under strong wind condition with seasonal variation: maximum (several hundred to thousands) in April to July, then decreasing to a few hundred after September. Higher electro conductivities of the drifting snow samples correlated well with breakup of sea ice windward of Syowa Station. Lower values were obtained after snow accumulated on sea ice at Kita-no-ura, windward bay area north-east and offshore of Syowa Station. These suggest that brine from sea ice changes the electroconductivity of drifting snow.