Video Experimental Relacionado
Updated: Sep 13, 2025
07:10
Production of Membrane-Filtered Phase-Shift Decafluorobutane Nanodroplets from Preformed Microbubbles
Published on: March 23, 2021
2.8K
La congelación de gotas impulsada por el polvo explica la fase superior de las nubes en los extratropicos del norte
D Villanueva1, M Stengel2, C Hoose3
1Department of Environmental Systems Science, ETH Zürich, Zürich, Switzerland.
Science (New York, N.Y.)
|July 31, 2025
Resumen
El aerosol de polvo influye significativamente en la formación de hielo en la cima de las nubes en el hemisferio norte. Este hallazgo, basado en 35 años de datos satelitales, aclara los factores que controlan las propiedades de las nubes y su impacto en el clima.
Área de la Ciencia:
- Ciencias atmosféricas
- Física de las nubes
- Ciencias del clima
Sus antecedentes:
- Las nubes de fase mixta entre -39 ° C y 0 ° C pueden tener capas de líquido o hielo, impactando el forzamiento radiativo y la precipitación.
- La frecuencia total de hielo en la nube (ITF) es una métrica clave, pero sus factores de control siguen sin estar claros.
Objetivo del estudio:
- Investigar los factores que controlan la frecuencia total de hielo en la cima de la nube (ITF).
- Para determinar el papel de los aerosoles en la glaciación de las nubes.
Principales métodos:
- Análisis de 35 años de datos satelitales.
- Análisis de correlación espacio-temporal entre el aerosol de polvo y el ITF.
- Comparación de las sensibilidades observadas del ITF con los experimentos de congelación de laboratorio.
Principales resultados:
- Se encontró una fuerte correlación espacio-temporal entre el aerosol de polvo y el ITF en el hemisferio norte entre -15 °C y -30 °C.
- La relación entre las sensibilidades del ITF a la temperatura y al polvo se alinea con las mediciones de congelación de gotas realizadas en laboratorio.
Conclusiones:
- La formación de hielo en la cima de las nubes (ITF) en este rango de temperatura se atribuye principalmente al aerosol de polvo.
- Los aerosoles de polvo actúan como un factor crucial que influye en la fase de las nubes y las interacciones climáticas.
Más Videos Relacionados
Videos de Conceptos Relacionados
02:33Phase Transitions: Sublimation and Deposition
18.0K
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...
18.0K
01:12Precipitation Processes
592
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...
592
02:39Phase Transitions: Vaporization and Condensation
18.6K
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...
18.6K
02:39Phase Transitions: Melting and Freezing
13.2K
Heating a crystalline solid increases the average energy of its atoms, molecules, or ions, and the solid gets hotter. At some point, the added energy becomes large enough to partially overcome the forces holding the molecules or ions of the solid in their fixed positions, and the solid begins the process of transitioning to the liquid state or melting. At this point, the temperature of the solid stops rising, despite the continual input of heat, and it remains constant until all of the solid is...
13.2K
01:10Types of Coprecipitation
877
Coprecipitation is the contamination of a precipitate by otherwise soluble species and occurs via different processes. In colloidal precipitates, coprecipitation occurs via surface adsorption. For instance, barium sulfate has a primary layer of adsorbed barium ions and a secondary layer of nitrate counterions. This results in contamination of the precipitate by barium nitrate.
Sometimes, ions in a crystal lattice can undergo isomorphous replacement by inclusions of similar charge and size. For...
Sometimes, ions in a crystal lattice can undergo isomorphous replacement by inclusions of similar charge and size. For...
877
01:03Sublimation
882
Sublimation is the direct transformation of a solid to a gaseous state. For instance, at standard pressure and room temperature, solid carbon dioxide sublimes to gaseous carbon dioxide. The phase diagram depicts the conditions required for sublimation. This process occurs at the solid-gas phase boundary and is not observed above the triple point of the substance. The reverse of sublimation is called deposition, where a gaseous substance condenses directly into a solid. Sublimation and...
882