関連する実験動画
Updated: Jul 12, 2026

09:34
Extraction and Characterization of Surfactants from Atmospheric Aerosols
Published on: April 21, 2017
まとめ
火山のエアロゾールは,シラスの形成に不可欠な,シラスの雲の中の超冷却された水滴を可能にします. これは,これまで未知の火山-サーラス雲の気候フィードバックループを示唆しています.
科学分野:
- 大気科学 大気科学
- クラウド物理学 クラウド物理
- 気候科学 気候科学
背景:
- サールス雲は主に氷の結晶で構成されています.
- 超冷却液体水 (SLW) は,非常に低温のシラス雲では珍しい.
- サーラス雲におけるSLWの形成メカニズムは,依然として活発な研究分野です.
研究 の 目的:
- Cirrus uncinus雲の頭部にある超冷却液滴を特定し,特徴づけること.
- サーラス雲の形成におけるこれらの滴の役割を調査する.
- -40°C以下の温度で超冷却ドロップルの現象を説明するために.
主な方法:
- FIREプロジェクト (第1回ISCCP地域実験) の極化ライダー測定を用いたものです.
- 特定の雲の形成における超冷却ドロップルの存在に関するデータを分析する.
- これらの滴と関連した雲凝縮核の性質を調査する.
主要な成果:
- 超冷却ドロップルは, -40°Cから -50°Cの間のシラス・ウンシナス細胞頭部で特定されました.
- これらの短命の液滴は,シラス雲の形成に大きく貢献しているようです.
- 大規模な火山雲の凝縮核に関連した凍結点の低気圧は,この珍しい観測を説明します.
結論:
- 火山のエアロゾールは,サールス雲の超冷却水の存在を容易にする可能性があります.
- この発見は,未知の火山-サーラス雲の気候フィードバックメカニズムを暗示しています.
- このフィードバックが気候に与える影響を理解するために,さらなる研究が必要である.
関連する概念動画
Global 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.
Phase Transitions: Vaporization and Condensation
The physical form of a substance changes on changing its temperature. For example, raising the temperature of a liquid causes the liquid to vaporize (convert into vapor). The process is called vaporization—a surface phenomenon. Vaporization occurs when the thermal motion of the molecules overcome the intermolecular forces, and the molecules (at the surface) escape into the gaseous state. When a liquid vaporizes in a closed container, gas molecules cannot escape. As these gas phase molecules...
Phase Transitions: Sublimation and Deposition
Some solids can transition directly into the gaseous state, bypassing the liquid state, via a process known as sublimation. At room temperature and standard pressure, a piece of dry ice (solid CO2) sublimes, appearing to gradually disappear without ever forming any liquid. Snow and ice sublimate at temperatures below the melting point of water, a slow process that may be accelerated by winds and the reduced atmospheric pressures at high altitudes. When solid iodine is warmed, the solid sublimes...
Volatilization
Volatilization gravimetry is an analytical technique that measures the mass lost due to the volatilization of the substance. This technique is used to estimate the amount of volatile material in a sample. To perform this method, heat a known amount of the sample to a high temperature in a crucible or other suitable vessel. The volatile substance in the sample evaporates, and the vapor is completely expelled from the crucible either by heating the sample or bubbling a stream of inert gas through...
Precipitation Processes
The experimental conditions in a gravimetric analysis should be optimized to maximize the particle size and purity of the obtained precipitate. Ideally, the concentration of the precipitating reagent should be low with effective stirring to maintain low relative supersaturation for the growth of large crystals. In homogeneous precipitation, the precipitant is slowly generated by a chemical reaction in the solution to avoid local reagent excesses. For example, urea decomposes gradually to...
Phase Diagrams
A phase diagram combines plots of pressure versus temperature for the liquid-gas, solid-liquid, and solid-gas phase-transition equilibria of a substance. These diagrams indicate the physical states that exist under specific conditions of pressure and temperature and also provide the pressure dependence of the phase-transition temperatures (melting points, sublimation points, boiling points). Regions or areas labeled solid, liquid, and gas represent single phases, while lines or curves represent...

