南極 の 氷 から の 大気 の ガス の 200万 年 前の 瞬間 画像
Yuzhen Yan1, Michael L Bender2,3, Edward J Brook4
1Department of Geosciences, Princeton University, Princeton, NJ, USA. yuzheny@princeton.edu.
Nature
|November 1, 2019
まとめ
温室効果ガスのレベルと南極の温度が低かったことを明らかにします
科学分野:
- 古代気候学
- 南極の氷河研究
- 温室効果ガスの分析
背景:
- 地球の気候は氷河期と氷河期間のサイクルを経験し,過去80万年にわたって顕著な10万年周期 ("100k世界") が支配している.
- "100万年前の世界"より"40万年前の世界" (2.8~120万年前) は,より弱い氷河周期を示し,大気中の二酸化炭素の変動が低いことが示唆されています.
- 直接的な大気温室効果ガスのデータは不足しており,この初期の気候状態の理解を制限しています.
研究 の 目的:
- 大気中の二酸化炭素,メタン,南極の温度を 古代の氷の核を使って再構築する
- 気候の変動を比較するために"40k世界"と最近の"100k世界".
主な方法:
- 東南極のアランヒルズ・ブルー・アイス・エリアから古代の,層図学的に不連続な氷の回収.
- 原始的な氷核のサンプルにおける二酸化炭素とメタンの濃度の分析
- デウテリウム/水素同位体比 (δD氷) を用いて南極の温度を測定する.
主要な成果:
- 2百万年以上前の原始的な氷の核は "40k世界"からの直接的な大気データを提供しました
- "40k世界"の気候特性は"100k世界"の範囲内にありましたが,氷河期間の振幅が減少しました.
- 氷河期における最も低い二酸化炭素,メタン,南極の気温は"40k世界"の気温よりも高かった.
結論:
- この研究は",40万年の世界"における 温室効果ガスと南極の気候における 氷河期間の変動の幅の減少を確認した.
- 氷河期における二酸化炭素の最小濃度が減少した.
- 古代の氷の核は 過去の気候の動態と変化を理解するために 莫大な直接的な証拠を提供します
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