氷河は,海洋環境に古くから存在し,不安定な有機物質の源である
Eran Hood1, Jason Fellman, Robert G M Spencer
1Environmental Science and Geography Program, University of Alaska Southeast, Juneau, Alaska 99801, USA. eran.hood@uas.alaska.edu
Nature
|December 25, 2009
まとめ
氷河の流れは,より古く,より反応性のある溶解有機物 (DOM) を沿岸の生態系に提供します. 気候に起因する氷河の融解は,この重要な海洋炭素源の質と量を大幅に変化させる可能性があります.
科学分野:
- 環境科学 環境科学
- 地質化学 地質化学
- 海洋学 海洋学 海洋学
背景:
- 河川の有機物質は河口の代謝に不可欠であり,その約5分の1を支えている.
- 沿岸の生態系は,河川からの土生地溶解有機物 (DOM) の量と質の変化に敏感である.
- DOMの可動性は伝統的に年齢と関連しており,若いDOMは生物学的利用性が高くなります.
研究 の 目的:
- 氷河の覆面と流水DOMの特性との関係を調査する.
- 氷河が供給する河川が,沿岸水域に流入するDOMの年齢と生物学的利用可能性にどのように影響するかを決定する.
主な方法:
- アラスカ湾の11の沿岸流域の川水のDOMの特徴付け,氷河の覆面が異なる (0-64%).
- DOMの (14) C年齢と海洋微生物に対する生物学的利用可能性の分析.
主要な成果:
- 氷河以外の河川とは対照的に,氷河河におけるDOMの生物利用性は,上昇する (14) C年齢と正に相関していた.
- 氷河が多く覆われている流域では,最も古いDOM (約. 4 kyr) で,最も高い可変性 (66%の生物利用可能性) を有しています.
- 氷河流域の流域は,氷河の大量の損失のために,高い流出率を示しています.
結論:
- 氷河流出は,海洋生態系への不安定な溶解有機炭素の重要な源である.
- 氷河の量に影響する気候の変化は,沿岸海に侵入するDOMの年齢,量,および反応性を変化させる可能性があります.
- 氷河は,かなりの水分貯蔵庫を代表し,将来の沿岸海の炭素ダイナミクスの重要な要因となっています.
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