ENSOは,過去千年にわたり,火山による強迫に一貫した対応をしていない
Sylvia G Dee1, Kim M Cobb2, Julien Emile-Geay3
1Rice University, Department of Earth, Environmental, and Planetary Sciences, Houston, TX 77005, USA. sylvia.dee@rice.edu.
Science (New York, N.Y.)
|March 29, 2020
まとめ
この研究では,大規模な火山噴火がエルニーニョ・サザン・オシレーション (ENSO) に弱い影響を与えていることがわかりました. 気候モデルでは,ENSOの火山の影響に対する感受性を過大評価している可能性があります.
科学分野:
- 古代気候学
- 気候科学
- 海と大気の動態
背景:
- エルニーニョ・サザン・オシレーション (ENSO) は,世界の気候パターンに大きな影響を与えている.
- ENSOは,火山の噴火などの外部の気象への敏感性はよく理解されていません.
- 過去のモデリング研究では,火山硫酸エロゾールとENSOとの関連が示唆されていますが,観察の証拠は不確実です.
研究 の 目的:
- ENSOにおける主要な火山噴火の影響を調査する.
- ENSOの火山への反応に関する気候モデル予測を検証するための観測データを提供する.
主な方法:
- 中央熱帯太平洋の化石サンゴを 古代気候のアーカイブとして利用しました
- ENSOの大規模な火山噴火の翌年の状態を評価するために,重ね合わせのエポック分析を適用しました.
主要な成果:
- 火山噴火の翌年には,エルニーニョのようなENSO反応へのわずかな傾向が観察されました.
- この傾向は統計的に有意ではなかった.
- 特に大きな1257サマラス噴火の後でも,有意なENSO反応は検出されなかった.
結論:
- この研究の結果は,ENSOの火山への反応は,いくつかの気候モデルによって予測されたよりも弱くなっていることを示唆しています.
- 観測されたENSOの変動は,火山噴火に対する強制反応を隠すか,より大きい可能性があります.
- 気候モデルを洗練し,火山活動とENSOの相互作用をよりよく理解するためにさらなる研究が必要です.
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