トリトンにおける羽根と風の表面および空中証拠
Science (New York, N.Y.)
|October 19, 1990
まとめ
海王星の月であるトリトンのエオリアの特徴は,風によって形作られ,特定の緯度帯に集中しています. 表面の風の流れは,風の支配的な方向が高度によって変化することを示し,動的な大気プロセスを示唆しています.
科学分野:
- 惑星科学 惑星科学
- 大気科学 大気科学
- 地質学 地質学 地質学
背景:
- ネプテュンの最大の月であるトリトンは,ユニークな表面特性を表しています.
- 風によって駆動されるエオリア過程は,惑星の表面の形成において重要な役割を果たしています.
- "ボイジャー"のような以前のミッションは,トリトンの表面と大気に関する初期データを提供した.
研究 の 目的:
- トリトンのエオリアの特徴を分類し,分析する.
- 動いているおよび過去のアエオール活動の緯度分布を決定する.
- 観測されたエオリアン指標に基づいて風の方向と速度を調査する.
主な方法:
- ヴォイジャーミッションで撮影されたエオリアの特徴のグループ化と分析.
- 様々なエオリアの特徴の緯度分布をマッピングする.
- 表面風の流れを測定して,風の方向と速度を推測する.
主要な成果:
- アクティブなエオリアの特徴は,緯度 -37 度から -62 度の間に集中しています.
- 過去のエオリア活動指標は,緯度 -15 度から -45 度の間で最も豊富です.
- 表面風の流れは,北から時計回りの方向で40度から80度までの主要な方向を示し,風は低高度では東から西に,より高い高度では東から西に移動します.
結論:
- トリトンのエオリアの活動は緯度的に制約されており,現在と過去のプロセスには明確なゾーンがあります.
- トリトンの風向きは高度に依存しており,複雑な大気循環パターンを示しています.
- エオリアの特徴は,トリトンの過去と現在の大気動力学に関する貴重な洞察を提供します.
関連する概念動画
01:16Surface Tension and Surface Energy
When a paint brush is immersed in water, the bristles wave freely inside the water. When it is taken out, the bristles stick together. The reason behind this effect is surface tension.
Consider a beaker filled with liquid. The bulk molecules in the liquid experience equal attractive forces on all sides with the surrounding molecules. However, the surface molecules experience a net attractive force downward due to the bulk molecules. The surface of the liquid behaves like a stretched membrane,...
Consider a beaker filled with liquid. The bulk molecules in the liquid experience equal attractive forces on all sides with the surrounding molecules. However, the surface molecules experience a net attractive force downward due to the bulk molecules. The surface of the liquid behaves like a stretched membrane,...
01:18Boundary Layer Characteristics
When a fluid encounters a solid surface, a boundary layer forms due to the interaction between the fluid's motion and the stationary surface. This phenomenon is characterized by a thin region adjacent to the surface where viscous forces dominate, influencing the fluid's velocity profile. The development of the boundary layer begins at the leading edge of the surface and evolves as the fluid moves downstream.As the fluid flows over the surface, friction between the fluid and the wall slows down...
01:20Momentum And Radiation Pressure
An object absorbing an electromagnetic wave would experience a force in the direction of propagation of the wave. This force occurs because electromagnetic waves contain and transport momentum. The force accounts for the wave's radiation pressure exerted on the object. Maxwell's prediction was confirmed in 1903 by Nichols and Hull by precisely measuring radiation pressures with a torsion balance. The measuring instrument had mirrors suspended from a fiber kept inside a glass container. Nichols...
01:26General External Flow Characteristics
The study of external flow is essential for creating structures and objects that interact efficiently and safely with moving fluids, such as air or water. When a body is immersed in a flowing fluid, it experiences two primary forces: drag, which opposes motion along the flow direction, and lift, which acts perpendicular to the flow. The shape, size, and orientation of the object influence these forces.Streamlined and Blunt Bodies in External FlowObjects in fluid flow are classified as...
01:06Tidal Forces
The origin of Earth's ocean tides has been a subject of continuous investigation for over 2000 years. However, the work of Newton is considered to be the beginning of the proper understanding of the phenomenon. Ocean tides are the result of gravitational tidal forces. These same tidal forces are present in any astronomical body; they are responsible for the internal heat that creates the volcanic activity on Io, one of Jupiter's moons, and the breakup of stars that get too close to black holes.
01:24Turbulent Flow
Turbulent flow is characterized by unpredictable fluctuations in velocity and pressure, which result in a chaotic fluid movement distinct from the orderly patterns of laminar flow. While laminar flow is governed by smooth, parallel layers with minimal mixing, turbulent flow exhibits highly irregular, three-dimensional patterns. This behavior arises due to instabilities in the fluid's velocity profile, and amplifies as the flow velocity increases. Minor disturbances, known as turbulent spots,...