プリオセンの赤道太平洋の温度とpHのグラデーションの分離

Madison G Shankle^1,2, Natalie J Burls³, Alexey V Fedorov^4,5

¹Department of Earth and Planetary Sciences, Yale University, New Haven, CT, USA. mgs23@st-andrews.ac.uk.

Nature

|October 21, 2021

まとめ

プレオセンの初期とミオセンの後半の赤道太平洋における海洋循環は,今日とは根本的に異なっていた. これは,上流が弱いにもかかわらず,生産性の向上を説明し,将来の気候変動の洞察を提供します.

科学分野:

古代海洋学
気候科学
海洋生態系

背景:

赤道太平洋のダイナミクスは地球の気候と生態系に大きな影響を与えます
過去のプレオセーンとミオセンの条件は,将来の地球温暖化シナリオの類似点として研究されています.
過去の海流の理解は将来の気候の影響を予測するのに極めて重要です

研究の目的:

プレオセンの初期とミオセンの後半における赤道太平洋の動態に関する矛盾する代理証拠を調和させる.
プレオセンの初期とミオセンの後半の循環体制を調査する.
この時期,東太平洋の生物学的生産性を向上させるメカニズムを理解する.

主な方法:

古代海洋学記録の分析
過去の海洋循環パターンの再構築
水の年齢,酸性,栄養分を含むプロキシデータの解釈

主要な成果:

新しい証拠は,現代の状況と比較して,プレオセンの初期とミオセンの末期に根本的に異なる循環体制を明らかにしています.
この変化したシステムは,より古く,より酸性で,栄養価の高い水を赤道太平洋に供給しました.
東太平洋の生物学的生産性の向上はこの独特な水質の供給によって説明されます

結論:

この研究は,プレオセンの初期とミオセンの後半の赤道太平洋における温度グラデーションの減少と生産性の向上のパラドックスを解明している.
過去の生産性の変化のメカニズムを提供し,地球温暖化の下の将来の海洋ダイナミクスの予測を伝える.
過去の動態を理解することはプレオセンのような気温に近づく温暖化世界での将来の変化を抑制するために極めて重要です

さらに関連する動画

10:43

Unraveling the Unseen Players in the Ocean - A Field Guide to Water Chemistry and Marine Microbiology

Published on: November 5, 2014

25.9K

08:15

Author Spotlight: Unveiling Plankton Response to Climate Change Through Time-Series Data and Artistic Expression

Published on: July 28, 2023

1.5K

関連する概念動画

01:50

Global Climate Change

25.1K

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.

25.1K

01:21

Isothermal Processes

4.1K

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...

Speciation Rates

pH Homeostasis

Acid-base homeostasis is essential for maintaining normal physiological activities in humans. The pH of various body fluids is strictly regulated because it is critical for the optimal activity of enzymes involved in metabolic reactions. Enzymes are basically proteins, so, any significant change in pH can affect their structure and activity. In humans, pH is regulated using three primary mechanisms— chemical buffer systems, respiratory regulation, and renal regulation.
Respiratory...

17.1K

00:53

Extraction: Effects of pH

754

Consider a neutral form of an amine, B, with a partition coefficient, K, in a liquid mixture containing organic and aqueous phases. The pH of the aqueous phase affects the charge on acidic and basic solutes, and the charged form is usually more soluble in the aqueous phase. Suppose the conjugate acid form of the amine is soluble only in the aqueous phase while the base form is soluble in both phases. Then the distribution coefficient, D, can be given as the ratio of amine concentration in the...

754

02:45

Calculating pH Changes in a Buffer Solution

54.6K

A buffer can prevent a sudden drop or increase in the pH of a solution after the addition of a strong acid or base up to its buffering capacity; however, such addition of a strong acid or base does result in the slight pH change of the solution. The small pH change can be calculated by determining the resulting change in the concentration of buffer components, i.e., a weak acid and its conjugate base or vice versa. The concentrations obtained using these stoichiometric calculations can be used...