スーパーENSOと世界の気候の振動は,ミレニアム・タイム・スケールで観測される
Lowell Stott1, Christopher Poulsen, Steve Lund
1Department of Earth Sciences, University of Southern California, 3651 Trousdale Parkway, Los Angeles, CA 90089, USA. stott@usc.edu
まとめ
プレイストセンの末期,太平洋の塩分はグリーンランドと変動した.
科学分野:
- パレオセアノグラフィー
- 気候科学 気候科学
- 海洋地質学 海洋地質学
背景:
- 熱帯太平洋の過去の気候変動を理解することは,世界の気候動態の解釈に不可欠です.
- 西太平洋の温かいプールは世界的な熱と水分輸送の重要な地域です.
研究 の 目的:
- 西洋熱帯太平洋の暖かいプールにおけるプレイストセンの後半の海水温度と塩分を復元する.
- 熱帯太平洋の条件と高緯度の気候サイクルとの関係を調査する.
主な方法:
- プランクトンのフォラミニフェラにおける酸素同位体 (デルタ18O) とマグネシウム/カルシウム組成の分析.
- カルシートデルタ18O記録の解凍により,温度と局所水デルタ18O信号を分離する.
主要な成果:
- グリーンランドの Dansgaard/Oeschger サイクルと強く相関する,支配的な塩分信号が特定されました.
- 高緯度冷却 (スタジアム) で塩分が高く,より暖かいインタースタジアムで塩分が低くなりました.
- 塩分変動は,熱帯太平洋の大気圏のシフトが現代のエルニニョ南方振動 (ENSO) に類似することを示唆しており,エルニニョはスタジアム,ラニニャはインタースタジアムと相関しています.
結論:
- 大気コンベクションの千年規模のシフトは,西熱帯太平洋に影響を与えた.
- これらのシフトは,スタジアム中の低気温温室効果ガス (CO2,N2O,CH4) と相関しています.
- 観測された熱帯外洋の変動パターンは,熱帯太平洋の動態と一致し,エルニーニョと負の相関関係があります.
関連する概念動画
The Carbon Cycle
Carbon is the basis of all organic matter on Earth, and is recycled through the ecosystem in two primary processes: one in which carbon is exchanged among living organisms, and one in which carbon is cycled over long periods of time through fossilized organic remains, weathering of rocks, and volcanic activity. Human activities, including increased agricultural practices and the burning of fossil fuels, has greatly affected the balance of the natural carbon cycle.
What is Weather?
Overview
What is Climate?
Climate refers to the prevailing weather conditions in a specific area over an extended period. As the saying goes, “Climate is what you expect. Weather is what you get.” Climate is influenced by geographic factors, such as latitude, terrain, and proximity to bodies of water.
Global Climate Change
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.
Ecological Disturbance
An ecological disturbance is a temporary disruption in the environment resulting from abiotic, biotic, or anthropogenic factors, causing a pronounced change in an ecosystem. The impact of an ecological disturbance, which can depend on its intensity, frequency, and spatial distribution, plays a significant role in shaping the species diversity within the ecosystem.Ecological disturbances can be caused by an event as small as the trampling of underbrush to an incident as wide-ranging as a forest...
Microbes and Climate Change
Microorganisms are pivotal agents in Earth's biogeochemical cycles, significantly influencing climate dynamics through their metabolic activities. These microbes modulate the levels of key greenhouse gases by both contributing to and helping mitigate climate change.Microbial Contributions to Greenhouse Gas EmissionsRising global temperatures accelerate microbial metabolism, which, in turn, speeds up the decomposition of organic matter. This process releases carbon dioxide (CO₂) through...


