CO2の貯蔵と南極海の深海への放出 千年から百年までの時間スケール
J W B Rae1, A Burke2, L F Robinson3
1School of Earth and Environmental Sciences, University of St Andrews, St Andrews, UK. jwbr@st-andrews.ac.uk.
Nature
|October 26, 2018
まとめ
氷河期における大気中の二酸化炭素 (CO2) の変化は,南極海の深海と関連している. 二酸化炭素のレベルが上昇すると 海のpHが低下し 深い海から炭素が放出されるのです
科学分野:
- 古代海洋学
- 気候科学
- 海洋地化学
背景:
- 氷河期間の大気中の二酸化炭素 (CO2) の変動の原因は,まだ完全に理解されていません.
- 深海,特に南洋は,大きな炭素貯蔵庫と換気経路により,氷河期間のCO2レベルを調節する上で重要な役割を果たしていると考えられています.
研究 の 目的:
- 過去4万年にわたる深海の炭素化学と 大気中の二酸化炭素濃度との関係を調査する
- 氷河期と氷河期間の周期で 大気中の二酸化炭素に 深い南洋が 大きく影響しているという仮説を検証するためです
主な方法:
- 深海のサンゴから採取したボロン同位体のデータを分析して,深海の南洋の pH を再構築する.
- 海洋のpH記録と大気中のCO2データを 関連付けています
主要な成果:
- 深南海のpHと大気中のCO2レベルとの間に強い相関が観察されました.
- 低気温の二酸化炭素は 低海のpHと一致し 深海の炭素貯蔵量が増加したことを示しています
- 大気中の二酸化炭素濃度上昇は 海のpH値上昇と関連しており 深い海から炭素が放出されていることを示唆している.
結論:
- 氷河期における大気中の二酸化炭素の変化を制御する 重要な要素です
- 南洋からの深海CO2放出は,百年の時間スケールでの急速な気候変化の間にダイナミックなフィードバックメカニズムとして機能します.
関連する概念動画
ATP Energy Storage and Release
14.4K
ATP is a highly unstable molecule. Unless quickly used to perform work, ATP spontaneously dissociates into ADP and inorganic phosphate (Pi), and the free energy released during this process is lost as heat. The energy released by ATP hydrolysis is used to perform work inside the cell and depends on a strategy called energy coupling. Cells couple the exergonic reaction of ATP hydrolysis with endergonic reactions, allowing them to proceed.
One example of energy coupling using ATP involves a...
One example of energy coupling using ATP involves a...
14.4K
Southern Blot
23.0K
Agarose gel electrophoresis is very useful in separating DNA fragments by size. Running a DNA ladder containing fragments of the known length alongside the sample helps determine the approximate length of the sample DNA fragments. However, additional steps are needed to verify the sequence identity of the sample DNA fragments.
Denatured DNA fragments must be transferred onto a carrier membrane from the gel to make it accessible to a probe - a small ssDNA fragment complementary to the target DNA...
Denatured DNA fragments must be transferred onto a carrier membrane from the gel to make it accessible to a probe - a small ssDNA fragment complementary to the target DNA...
23.0K
Storage
410
A schema is a mental framework that helps individuals organize and interpret information. Schemata, formed from previous experiences, influence how we process new information: how we encode it, the inferences we make, and how we retrieve it. For instance, a schema for what a typical classroom looks like might include desks, a teacher's desk, a whiteboard, and students in such an environment. This expectation helps us quickly understand and navigate new classrooms without needing to analyze...
410
Sugars as Energy Storage Molecules
9.9K
Sugar (a simple carbohydrate) metabolism (chemical reactions) is a classic example of the many cellular processes that use and produce energy. Living things consume sugar as a major energy source because sugar molecules have considerable energy stored within their bonds. Consumed carbohydrates have their origins in photosynthesizing organisms like plants. During photosynthesis, plants use the energy of sunlight to convert carbon dioxide gas into sugar molecules, like glucose. Because this...
9.9K
Fats as Energy Storage Molecules
27.0K
Triglycerides are a form of long-term energy storage molecules. They are made of glycerol and three fatty acids. To obtain energy from fat, triglycerides must first be broken down by hydrolysis into their two principal components, fatty acids and glycerol. This process, called lipolysis, takes place in the cytoplasm. The resulting fatty acids are oxidized by β-oxidation into acetyl-CoA, which is used by the Krebs cycle. The glycerol that is released from triglycerides after lipolysis...
27.0K
Energy-releasing Steps of Glycolysis
146.8K
Glycolysis is divided into two phases based on whether energy is utilized or released. While the first phase consumes ATP, the second phase produces energy in the form of ATP and NADH. The energy is released over a sequence of reactions that turns G3P into pyruvate. The energy-releasing phase—steps 6-10 of glycolysis—occurs twice, once for each of the two 3-carbon sugars produced during steps 1-5 of the first phase.
The first energy-releasing step—the 6th step of glycolysis...
The first energy-releasing step—the 6th step of glycolysis...
146.8K


