スカンジナビア,シベリア,北極海の氷河:ホロセンの大気中のCO2変動の影響
Science (New York, N.Y.)
|August 11, 1989
まとめ
ユーラシア北極のプレイストセンの氷床は,大気中の二酸化炭素 (CO2) の変化により,前進し,後退しました. 250ppm以下のCO2下では,大規模な氷床が形成され,温暖化により崩壊し,現在の氷の状態が回復した.
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:
- ユーラシア北極圏のプレイストセンの氷床の振る舞いは複雑である.
- 氷床の前進と後退の要因を理解することは,将来の気候シナリオを予測するために不可欠です.
研究 の 目的:
- 大気中の二酸化炭素 (CO2) 濃度変化が,ユーラシア北極におけるプレイストセンの氷床の前進と後退に与える影響を評価する.
- 広範囲の氷床の形成と崩壊のためのCO2値を決定する.
主な方法:
- 結合された氷床-氷棚のダイナミクスをシミュレートするコンピュータモデルを使用しました.
- 異なる大気中のCO2濃度でシミュレーションを行った.
主要な成果:
- バレンツ海,カラ海,東シベリア海,北極海の一部を覆う海洋ベースの氷床は,約250パーツ/百万分のCO2の値を下回って形成されました.
- 大気中のCO2の上昇と関連したホロセンの気候温暖化は,この広範囲の氷河期の崩壊を引き起こすのに十分であった.
結論:
- 大気中のCO2濃度の観測された変化は,ユーラシア北極におけるプレイストセンの氷床の前進と後退の合理的な原動力である.
- このモデルは,大規模な氷床の崩壊と,CO2による温暖化による現在の氷の状態の回復をシミュレートすることに成功した.
関連する概念動画
01:50Global 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.
01:27Microbes 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...
01:14The 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.
01:16What 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.
01:21Isothermal Processes
A thermodynamic process that occurs at constant temperature is called an isothermal process. Heat slowly flows into the system or out of the system to maintain thermal equilibrium. Processes involving phase changes like water evaporation into steam or freezing water into ice at a constant temperature are examples of Isothermal Processes.
An ideal gas can also undergo isothermal expansion or compression.
For example, consider 1 mole of an ideal gas inside an isolated cylinder at initial volume V...
An ideal gas can also undergo isothermal expansion or compression.
For example, consider 1 mole of an ideal gas inside an isolated cylinder at initial volume V...
01:21Isochoric and Isobaric Processes
A thermodynamic process that occurs at constant volume is called an isochoric process. According to the first law of thermodynamics, heat supplied or removed from the system is partially utilized to perform work and change the internal energy of the system. However, in an isochoric process, the volume remains constant. Hence, the work done by the system is zero. Therefore, the exchange of heat changes the internal energy of the system only.
Suppose 1000 g of water is heated from 40 degrees...
Suppose 1000 g of water is heated from 40 degrees...