海洋の混合に利用できるエネルギーの再分配は,内部波の長距離伝播によって行われます
1Applied Physics Laboratory and School of Oceanography, University of Washington, 1013 NE 40th Street, Seattle, Washington 98105, USA. malford@apl.washington.edu
Nature
|May 9, 2003
まとめ
内部重力波は海洋の混合を促し,気候と海洋生態系に影響を与えます. この研究は,それらの伝播をマッピングし,年間を通して地球全体の混合パターンに影響を与えるエネルギーフローを明らかにします.
科学分野:
- 海洋学 海洋学とは
- 流体力学 流体力学
- 気候科学 気候科学
背景:
- 海洋の混合は,汚染物質の分散,海洋の生産性,そして地球規模の気候規制にとって極めて重要です.
- 海洋層分化に沿って広がる内部重力波は,海洋の混合の主要な原動力である.
- 気候モデルを改善するために,内部波散乱のグローバルマップが必要です.
研究 の 目的:
- 歴史的なモアリングデータから水平の内部波の伝播を計算する.
- 内部波の伝播を,そのエネルギー源の条件と関連付けること.
- グローバルな混合のために利用可能なエネルギーの時空分布を理解するために.
主な方法:
- 60の歴史的なモアリングからのデータを活用して,水平の内部波の拡散を計算した.
- 分析されたエネルギー周波数範囲は,近慣性および半日間の潮周波数です.
- これらの内部波に関連した量化されたエネルギーフロー.
主要な成果:
- 近慣性帯と半日間の潮帯の両方のエネルギーフローは,約1kW×m−1です.
- これらの流れは,エネルギー投入総量の15~50%を占め,エネルギー源地域から遠ざかっています.
- 近惰性波のエネルギー流は冬にはより強く,潮流は年中一貫している.
結論:
- 内部重力波は,海洋における混合エネルギーの空間的および時間的な分布を大きく影響する.
- 近惰性および潮波の伝播を理解することは,海洋の混合とその気候への影響を予測する鍵です.
- この発見は,気候モデルを改良し,海洋の動態を理解するために不可欠なデータを提供します.
関連する概念動画
01:07Propagation of Waves
3.2K
When a wave propagates from one medium to another, part of it may get reflected in the first medium, and part of it may get transmitted to the second medium. In such a case, the interface of the two mediums can be considered as a boundary that is neither fixed nor free.
Consider a scenario where a wave propagates from a string of low linear mass density to a string of high linear mass density. In such a case, the reflected wave is out of phase with respect to the incident wave, however the...
Consider a scenario where a wave propagates from a string of low linear mass density to a string of high linear mass density. In such a case, the reflected wave is out of phase with respect to the incident wave, however the...
3.2K
01:10Kinetic and Potential Energy of a Wave
6.5K
All forms of waves carry energy; this is directly visualized in nature. For instance, the waves of earthquakes are so intense that they can shake huge concrete buildings, causing them to fall. Loud sounds can damage nerve cells in the inner ear, causing permanent hearing loss. The waves of the oceans can erode beaches.
In mechanical waves, the amount of energy is related to their amplitude and frequency. In the context of the above examples, large-amplitude earthquakes produce large...
In mechanical waves, the amount of energy is related to their amplitude and frequency. In the context of the above examples, large-amplitude earthquakes produce large...
6.5K
01:04Travelling Waves
7.3K
A wave is a disturbance that propagates from its source, repeating itself periodically, and is typically associated with simple harmonic motion. Mechanical waves are governed by Newton's laws and require a medium to travel. A medium is a substance in which a mechanical wave propagates, and the medium produces an elastic restoring force when it is deformed.
Water waves, sound waves, and seismic waves are some examples of mechanical waves. For water waves, the wave propagation medium is...
Water waves, sound waves, and seismic waves are some examples of mechanical waves. For water waves, the wave propagation medium is...
7.3K
00:58Energy and Power of a Wave
5.2K
The total energy associated with a wavelength is the sum of the potential energy and the kinetic energy. The average rate of energy transfer associated with a wave is called its power, which is total energy divided by the time it takes to transfer the energy. For a sinusoidal wave, energy and power are proportional to the square of both the amplitude and the angular frequency.
Waves can also be concentrated or spread out, as characterized by the intensity of the wave. Intensity is directly...
Waves can also be concentrated or spread out, as characterized by the intensity of the wave. Intensity is directly...
5.2K
01:07Reflection of Waves
4.8K
When a wave travels from one medium to another, it gets reflected at the boundary of the second medium. A common example of this is when a person yells at a distance from a cliff and hears the echo of their voice. The sound waves (longitudinal waves) traveling in the air are reflected from the bounding cliff. Similarly, flipping one end of a string whose other end is tied to a wall causes a pulse (transverse wave) to travel through the string, which gets reflected upon reaching the wall. In...
4.8K
01:07Interference and Superposition of Waves
7.4K
When two waves of the same nature occur in the same region simultaneously, they result in interference. Interference of waves implies that the net effect of the waves is the sum of the individual waves' effects. However, it does not imply that the individual waves affect the propagation of other waves.
Interference occurs in mechanical waves, such as sound waves, waves on a string, and surface water waves. Mechanical waves correspond to the physical displacement of particles. Hence,...
Interference occurs in mechanical waves, such as sound waves, waves on a string, and surface water waves. Mechanical waves correspond to the physical displacement of particles. Hence,...
7.4K