見えない船の痕跡は,エアロゾールに対する大きな雲の感受性を示しています
Peter Manshausen1, Duncan Watson-Parris2, Matthew W Christensen3
1Atmospheric, Oceanic and Planetary Physics, Department of Physics, University of Oxford, Oxford, UK. peter.manshausen@physics.ox.ac.uk.
Nature
|October 5, 2022
まとめ
見える船跡がない場合でも エアロゾール排出は 雲の性質を大きく変えます 輸送による気候の冷却効果は以前よりも大きいことが示されています.
科学分野:
- 大気科学
- 気候科学
- エアロゾールと雲の相互作用
背景:
- 雲の反射性は,凝縮核として作用するエアロゾール粒子によって影響されます.
- 人為的なエアロゾールは,衝撃雲のドロップ数,液体の水,雲の分数を増加させるが,大きな不確実性がある.
- エアロゾールと雲の相互作用を 研究するために 船舶の軌跡が使われていますが 汚染された雲のほんのわずかな部分しか それを示していません
研究 の 目的:
- 船舶の軌跡がない場合でも,船舶の排出が雲の性質に与える影響を定量化します.
- 衛星で観測できる船の軌道を超えて,エアロゾールと雲の相互作用を評価するための新しい方法を開発する.
- 大西洋貿易の積層地域における雲に対する船舶の影響を調査する.
主な方法:
- 船舶の排出によるエアロゾールと雲の相互作用を定量化するための新しい方法論の開発
- 大西洋貿易の累積地域における雲の性質を分析し,船の軌跡がほとんど見えない地域に焦点を当てた.
- 輸送による雲の性質の変化を直接検出する.
主要な成果:
- エアロゾルの排出は 船舶の軌跡が見えない場合でも 雲の性質を大幅に変化させます
- この新しい方法では 雲の滴数の濃度が増加し 液体の水の反応が陽性であったが 目に見える痕跡はなかった.
- 海運による雲の性質の変化は,大西洋貿易の累積地域において直接観察された.
結論:
- 見える船跡だけに 頼る以前の研究は 選択のバイアスを 持っていたかもしれません
- 観測された強い液体水路反応は,輸送によるより大きなエアロゾール冷却効果を暗示しています.
- この冷却効果は,現在の気温の傾向よりも高い気候感受性を隠す可能性があります.
関連する概念動画
01:26Influence of Earth's Curvature and Atmospheric Refraction on Leveling
221
During leveling, the Earth's curvature and atmospheric refraction introduce deviations in the line of sight from a true horizontal reference. When the line of sight is leveled, it remains perpendicular to the plumb line only at a single point. Beyond this, it deviates due to the Earth’s curvature, represented by the correction C. For a sight distance D, the deviation can be derived using the relationship:This relationship shows that the deviation increases quadratically with distance.
221
01:05Doppler Effect - II
3.5K
The Doppler effect has several practical, real-world applications. For instance, meteorologists use Doppler radars to interpret weather events based on the Doppler effect. Typically, a transmitter emits radio waves at a specific frequency toward the sky from a weather station. The radio waves bounce off the clouds and precipitation and travel back to the weather station. The radio frequency of the waves reflected back to the station appears to decrease if the clouds or precipitation are moving...
3.5K
01:06Echo
584
The human ear cannot distinguish between two sources of sound if they happen to reach within a specific time interval, typically 0.1 seconds apart. More than this, and they are perceived as separate sources.
Imagine the sound is reflected back to the ears. Assuming that the source is very close to the human, the difference between hearing the two sounds—the emitted sound and the reflected sound—may be more than the minimum time for perceiving distinct sounds. If this is the case,...
Imagine the sound is reflected back to the ears. Assuming that the source is very close to the human, the difference between hearing the two sounds—the emitted sound and the reflected sound—may be more than the minimum time for perceiving distinct sounds. If this is the case,...
584
01:18Variation of Atmospheric Pressure
2.7K
Change in atmospheric pressure with height is particularly interesting. The decrease in atmospheric pressure with increasing altitude is due to the decreasing gravitational force per unit area as we move away from the surface of the earth.
Assuming the air temperature is constant at a given altitude and that the ideal gas law of thermodynamics describes the atmosphere to a good approximation, one can find the variation of atmospheric pressure with height.
Let p(y) be the atmospheric pressure at...
Assuming the air temperature is constant at a given altitude and that the ideal gas law of thermodynamics describes the atmosphere to a good approximation, one can find the variation of atmospheric pressure with height.
Let p(y) be the atmospheric pressure at...
2.7K
01:25Atomic Absorption Spectroscopy: Interference
970
Interference leads to systematic error in atomic absorption (AA) measurements by enhancing or diminishing the analytical signal or the background. These interferences can be grouped into three main categories: spectral interference, chemical interference, and physical interference.
Spectral interference occurs when signals from other elements or molecules overlap with the analyte signal, falsely elevating or masking the analyte's absorbance. This interference can be corrected using Zeeman,...
Spectral interference occurs when signals from other elements or molecules overlap with the analyte signal, falsely elevating or masking the analyte's absorbance. This interference can be corrected using Zeeman,...
970
01:30Atomic Emission Spectroscopy: Interference
259
In atomic emission spectroscopy (AES), high-temperature atomizers excite a broad range of elements and molecules that generate complex emissions from sources such as oxides, hydroxides, and flame combustion products in the flame or plasma. Several strategies can be employed to minimize spectral interferences caused by overlapping emission lines or bands. These include increasing instrument resolution, choosing alternative emission lines, optimally placing the detector in low-background regions,...
259