熱帯太平洋の地下気温の急激な変化は,エルニーニョの変化と関連しています
1T. P. Guilderson, Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138, USA, and Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA. D. P. Sc.
まとめ
ガラパゴス島の地表水中の放射性炭素含有量は1976年以降急激に増加し,海表温度の変化と一致しました. これは,東の熱帯太平洋の変化を示唆しています.
科学分野:
- 海洋学 海洋学 海洋学
- 古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは
- 放射性炭素年代測定法による年代測定
背景:
- エルニーニョの南部振動 (ENSO) は,世界の気候に大きな影響を与える.
- 過去のENSOの動態を理解することは,将来の出来事を予測する上で極めて重要です.
- サンゴの記録は,過去の海洋状態を再構築するための貴重な代理情報を提供します.
研究 の 目的:
- 熱帯太平洋東部における表面水の放射性炭素 (14C) と海面温度 (SST) の変化を調査する.
- 特に1976年のエルニーニョ現象の後,これらの変化のタイミングと影響を決定する.
- 観測された変化とENSOの行動の間の潜在的な関連性を評価する.
主な方法:
- 珊瑚の記録から放射性炭素 (14C) の含有量の分析.
- 同じサンゴの記録から海面温度 (SST) の再構築.
- 14CとSSTのデータと季節性およびイベントベースの気候データとの相関関係.
主要な成果:
- 表面水中の14C含有量の著しく急激な増加は,1976年以降の上流期 (7月~9月) に観察されました.
- 上昇の季節の海面温度 (SST) も,1976年以降の顕著な変化を示した.
- 14CとSSTの観測されたシフトは同期であり,東熱帯太平洋の垂直熱構造の変化を示しています.
結論:
- 1976年のエルニーニョ現象は,東熱帯太平洋の海洋学的な条件に重大な変化をもたらした.
- その後のエルニーニョ現象の頻度と強度に影響を与えた可能性が高い.
- この研究は,熱帯太平洋の気候変動に対する感受性とそのENSOへの影響を強調しています.
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