南極海氷が氷河期と氷河期間のCO2変動に及ぼす影響
1Scripps Institution of Oceanography, University of California, San Diego, La Jolla 92093-0244, USA. britt@cmdl.noaa.gov
Nature
|March 21, 2000
まとめ
氷河期には大気中の二酸化炭素 (CO2) レベルが低下し,これは南極の海氷と関連しています. この研究モデルは深海換気を減少させ,CO2の差とCO2の温度関係について67ppmの違いを説明した.
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
- 海洋学 海洋学とは
- 気候モデリング
背景:
- 氷河期の大気中のCO2は,氷河期間の間期よりも約80ppm低かった.
- 以前のモデルでは,CO2レベルと深海のO2,炭素同位体,およびカルシット飽和度を調和させるのに苦労しました.
- 南極大陸の気温と大気中のCO2の間には,以前は説明できなかった強い関連がある.
研究 の 目的:
- 南極の気温と大気中のCO2の間の氷河期と氷河期間の関連性を調査する.
- 55°南緯度の南に限られた深水上流の箱モデルをテストする.
- 低氷河期CO2レベルとその南極条件との関連を説明するために.
主な方法:
- 海洋一般循環をシミュレートするボックスモデルを使用した.
- 55°Sの南に限られた深水の上流,以前のモデル仮定に挑戦する.
- 南極海氷による深水換気の減少の影響について調査した.
主要な成果:
- このモデルは,観測された氷河期と氷河期間のCO2差の67ppmを再現した.
- 南極地域における空気と海のガス交換の減少が,主な要因として特定された.
- 発見は,O2,炭素同位体,およびカルシット飽和度に関する観測的制約と一致しています.
結論:
- 低氷河期の大気中のCO2は,広範囲の南極海氷によって引き起こされる深海換気の減少の結果である可能性があります.
- 年中または冬/夏の海氷の組み合わせは,層格化を誘発し,ガス交換を制限する可能性があります.
- このモデルは,氷河期CO2減少とその南極気候との関連について一貫した説明を提供します.
関連する概念動画
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.
Calculating and Interpreting the Linear Correlation Coefficient
The correlation coefficient, r, developed by Karl Pearson in the early 1900s, is numerical and provides a measure of strength and direction of the linear association between the independent variable, x, and the dependent variable, y. Hence, it is also known as the Pearson product-moment correlation coefficient. It can be calculated using the following equation:
Carbon Dioxide Transport in the Blood
Carbon dioxide (CO2) transport in the blood is critical to human physiology. On average, our body cells produce around 200 mL of CO2 per minute, precisely the quantity expelled by the lungs. This process involves the transportation of CO2 from the tissue cells to the lungs in three primary forms.
Forms of CO2 Transport
1. Dissolved in plasma: A small percentage (7-10%) of CO2 is transported and dissolved directly in the plasma.
2. Carbaminohemoglobin: Just over 20% of CO2 is chemically bound to...
Forms of CO2 Transport
1. Dissolved in plasma: A small percentage (7-10%) of CO2 is transported and dissolved directly in the plasma.
2. Carbaminohemoglobin: Just over 20% of CO2 is chemically bound to...
Influence of Earth's Curvature and Atmospheric Refraction on Leveling
During leveling, the Earth's curvature and atmospheric refraction introduce deviations in the line of sight from a true horizontal reference. When the line of sight is leveled, it remains perpendicular to the plumb line only at a single point. Beyond this, it deviates due to the Earth’s curvature, represented by the correction C. For a sight distance D, the deviation can be derived using the relationship:This relationship shows that the deviation increases quadratically with distance. Over a...
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...


