過去80万年における軌道と千年間の南極気候の変動
J Jouzel1, V Masson-Delmotte, O Cattani
1Laboratoire des Sciences du Climat et l'Environnement, Institut Pierre Simon Laplace, CEA-CNRS-Université de Versailles Saint-Quentin en Yvelines, CE Saclay, Gif-sur-Yvette, France. jean.jouzel@lsce.ipsl.fr
まとめ
南極の氷からの新しい高解像度デュテリウムプロファイルは,気候記録を80万年前まで延長しています. これらのデータは,過去の気候現象を明らかにし,軌道周期が氷河間期間の強度に影響を及ぼすことを示唆しています.
科学分野:
- 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
- 氷河学 氷河学とは
- 気候モデリング
背景:
- 氷の芯は,貴重な古気候アーカイブを提供します.
- 南極の氷芯は,長期的な気候再構築を提供する.
- 氷の中のデュテリウムは,過去の気温の代理です.
研究 の 目的:
- 南極大陸の氷のコーリングのための欧州プロジェクト全体から高解像度のデュテリウムプロフィールを提示する. ドームC氷芯.
- 南極の気候記録を海洋同位体ステージ20.2 (約. 800,000年前のこと).
- Dansgaard-Oeschger現象と南極の気候の変動性との関係を調査する.
主な方法:
- ドームCの氷芯の高解像度デュテリウム分析.
- 水の同位体を含む大気一般循環モデル実験.
- グリーンランドと南極の記録の間の気候イベントの対応の分析.
主要な成果:
- 800,000年をカバーする連続した高解像度デュテリウムプロファイルが現在利用可能になっています.
- モデル実験は,デュテリウム記録を温度プロキシとして解釈することを支持しています.
- Dansgaard-Oeschgerのような現象と,その南極の類似現象は,以前の氷河期における類似の振幅で特定されました.
結論:
- 南極ドームCの記録は,過去の気候変動の詳細な見方を提供しています.
- 軌道強制 (傾きとプレセッション) は,氷河間期間の強度を調節する可能性が高い.
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 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.
Conditions on Early Earth
Around 4 billion years ago, oceans began to condense on earth while volcanic eruptions released nitrogen, carbon dioxide, methane, ammonia, and hydrogen into the primordial atmosphere. However, organisms with the characteristics of life were not initially present on earth. Scientists have used experimentation to determine how organisms evolved that could grow, reproduce, and maintain an internal environment.
Variation of Atmospheric Pressure
Change in atmospheric pressure with height is particularly interesting. The decrease in atmospheric pressure with increasing altitude is due to the decreasing gravitational force per unit area as we move away from the surface of the earth.
Assuming the air temperature is constant at a given altitude and that the ideal gas law of thermodynamics describes the atmosphere to a good approximation, one can find the variation of atmospheric pressure with height.
Let p(y) be the atmospheric pressure at...
Assuming the air temperature is constant at a given altitude and that the ideal gas law of thermodynamics describes the atmosphere to a good approximation, one can find the variation of atmospheric pressure with height.
Let p(y) be the atmospheric pressure at...
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...


