関連する実験動画
Updated: Jun 4, 2026
07:28
Evolution of Staircase Structures in Diffusive Convection
Published on: September 5, 2018
温暖な大西洋水による北極への近代的な熱伝達の強化
Robert F Spielhagen1, Kirstin Werner, Steffen Aagaard Sørensen
1Academy of Sciences, Humanities, and Literature, 53151 Mainz, Germany. rspielhagen@ifm-geomar.de
Science (New York, N.Y.)
|January 29, 2011
まとめ
北極海に流入する大西洋の水温は,2000年ぶりの最高水準に達している. この前例のない温暖化は,地球温暖化が北極で増幅され,海氷の分布に影響を及ぼしている.
科学分野:
- 海洋学 海洋学 海洋学
- 気候科学 気候科学
- 北極研究 アークティック研究
背景:
- 北極は,世界の他の地域よりも急速に温暖化しています.
- 北に向かって流れる大西洋水は,北極の熱伝導と海氷の分布の主な要因である.
- 大西洋水の変動に関する歴史的記録は,約150年に限られている.
研究 の 目的:
- 過去2000年にわたって北極圏の海洋温度変動の複数十年規模の記録を再構築する.
- 大西洋水の自然的な変動性と,北極の気候システムへの影響を理解する.
- 長期的な気候変動の文脈で最近の気温の動向を評価する.
主な方法:
- 西スヴァルバルド (79°N) 沖から採取された海洋堆積物核の分析.
- 過去の海洋温度の古海洋学的な再構築.
- 堆積物のデータと歴史的な気候記録の相関.
主要な成果:
- 2000年の海洋温度変動の記録が確立されました.
- 21世紀初頭,北極海に流入する大西洋水の気温は,2000年の記録の中で前例のないものであることが判明しました.
- 最近の温暖化傾向は,地球温暖化が北極で増幅されていることと潜在的に結びついている.
結論:
- この研究は,北極の気候変動を理解するための重要な長期的な文脈を提供します.
- 北極に流入する現在の大西洋水温は,過去2千年と比較して非常に高い.
- これらの発見は,地球温暖化が北極の気候システムと海氷に及ぼす重大な影響を強調しています.
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.
01:20Mechanisms of Heat Transfer II
In convection, thermal energy is carried by the large-scale flow of matter. Ocean currents and large-scale atmospheric circulation, which result from the buoyancy of warm air and water, transfer hot air from the tropics toward the poles and cold air from the poles toward the tropics. The Earth’s rotation interacts with those flows, causing the observed eastward flow of air in the temperate zones. Convection dominates heat transfer by air, and the amount of available space for the airflow...
01:19Mechanism of heat transfer
Understanding heat transfer mechanisms is essential for understanding how our bodies maintain balance in different environmental conditions. When the environment is thermoneutral, the body is in a state of balance, neither using nor releasing energy to maintain its core temperature. However, when the environment is not thermoneutral, the body employs four heat transfer mechanisms to maintain homeostasis: conduction, convection, evaporation, and radiation. These mechanisms facilitate heat...
01:14Mechanisms of Heat Transfer
Heat transfer between the human body and its environment occurs through four main mechanisms: conduction, convection, radiation, and evaporation.
Conduction, accounting for approximately 3% of body heat loss at rest, is the process of exchanging heat between molecules of two materials in direct contact. This can result in both heat loss and gain. For instance, when the body is submerged in water, which conducts heat 20 times more effectively than air, it can either lose or gain significant heat.
Conduction, accounting for approximately 3% of body heat loss at rest, is the process of exchanging heat between molecules of two materials in direct contact. This can result in both heat loss and gain. For instance, when the body is submerged in water, which conducts heat 20 times more effectively than air, it can either lose or gain significant heat.
01:14Mechanisms of Heat Transfer I
Just as interesting as the effects of heat transfer on a system are the methods by which the heat transfer occur. Whenever there is a temperature difference, heat transfer occurs. It may occur rapidly, such as through a cooking pan, or slowly, such as through the walls of a picnic ice box. So many processes involve heat transfer that it is hard to imagine a situation where no heat transfer occurs. Yet, every heat transfer takes place by only three methods: conduction, convection, and radiation.
01:12Heat Flow and Specific Heat
Heat is a type of energy transfer that is caused by a temperature difference, and it can change the temperature of an object. Since heat is a form of energy, its SI unit is the joule (J). Another common unit of energy often used for heat is the calorie (cal), which is defined as the energy needed to change the temperature of 1 g of water by 1 °C, specifically between 14.5 °C and 15.5 °C, since the energy needed shows a slight temperature dependence. Another commonly used unit is the kilocalorie...