Video Experimental Relacionado

Updated: Aug 7, 2025

In vitro Cell Culture Model for Toxic Inhaled Chemical Testing

In vitro Cell Culture Model for Toxic Inhaled Chemical Testing

Published on: May 8, 2014

Activación del cloro y agotamiento del ozono inducido por el aerosol de incendios forestales

Susan Solomon¹, Kane Stone², Pengfei Yu³

¹Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA. solos@mit.edu.

|March 8, 2023

Resumen

Los incendios forestales australianos de 2020 impactaron significativamente los niveles de cloro y ozono en la estratosfera. Los aerosoles de incendios forestales aumentaron el agotamiento del ozono, retrasando potencialmente la recuperación de la capa de ozono.

Área de la Ciencia:

Química de la atmósfera
Ciencia de la estratosfera
Ciencias del medio ambiente

Sus antecedentes:

Los incendios forestales australianos de 2020 causaron cambios significativos en el cloro estratosférico y el ozono en el hemisferio sur.
Se sospecha que los aerosoles de incendios forestales influyen en los procesos químicos estratosféricos que afectan al agotamiento del ozono.

Objetivo del estudio:

Investigar el impacto de los aerosoles de incendios forestales en la activación del cloro estratosférico y la química del agotamiento del ozono.
Para probar la hipótesis de que los aerosoles de incendios forestales aumentan la solubilidad del ácido clorhídrico y las tasas de reacción heterogéneas.

Principales métodos:

Comparación de las observaciones atmosféricas con simulaciones de modelos que incorporan un mecanismo de aerosol de incendios forestales propuesto.
Análisis de las abundancias estratosféricas de ácido clorhídrico, nitrato de cloro y ácido hipocloroso.

Principales resultados:

Las simulaciones de modelos mostraron una buena concordancia con los cambios observados en las especies claves de cloro.
Se descubrió que la química de los aerosoles de Wildfire aumentaba el área del agujero de ozono antártico y agotaba el ozono de latitudes medias del sur en un 3-5%.

Conclusiones:

Los aerosoles de incendios forestales activan el cloro reactivo, aumentando la pérdida de ozono a temperaturas estratosféricas más cálidas.
El aumento de la frecuencia e intensidad de los incendios forestales puede impedir la recuperación de la capa de ozono en un clima más cálido.

Más Videos Relacionados

Generation of a Chronic Obstructive Pulmonary Disease Model in Mice by Repeated Ozone Exposure

Generation of a Chronic Obstructive Pulmonary Disease Model in Mice by Repeated Ozone Exposure

Published on: August 25, 2017

Controlled-release of Chlorine Dioxide in a Perforated Packaging System to Extend the Storage Life and Improve the Safety of Grape Tomatoes

Controlled-release of Chlorine Dioxide in a Perforated Packaging System to Extend the Storage Life and Improve the Safety of Grape Tomatoes

Published on: April 7, 2017

Videos de Conceptos Relacionados

Radical Substitution: Halogenation of Alkanes and Alkyl Substituents

Radical Substitution: Halogenation of Alkanes and Alkyl Substituents

In the presence of heat or light, alkanes react with molecular halogens to form alkyl halides by a substitution reaction called radical halogenation. This reaction has three steps: initiation, propagation, and termination, as seen in the radical chlorination of methane to produce methyl chloride.
In the initiation step of the reaction, the chlorine molecule undergoes homolytic cleavage in the presence of light or heat, forming two highly reactive chlorine radicals. Propagation occurs in two...

Oxidative Cleavage of Alkenes: Ozonolysis

Oxidative Cleavage of Alkenes: Ozonolysis

In ozonolysis, ozone is used to cleave a carbon–carbon double bond to form aldehydes and ketones, or carboxylic acids, depending on the work-up.
Ozone is a symmetrical bent molecule stabilized by a resonance structure.

Radical Substitution: Allylic Chlorination

Radical Substitution: Allylic Chlorination

Typically, when alkenes react with halogens at low temperatures, an addition reaction occurs. However, upon increasing the temperature or under reaction conditions that form radicals, providing a low but steady concentration of halogen radicals, allylic substitution reaction is favored. This is because allylic hydrogens are very reactive as the formed intermediate is resonance stabilized. For example, when propene is treated with chlorine in the gas phase at 400 °C, it undergoes allylic...

meta-Directing Deactivators: –NO2, –CN, –CHO, –&NoBreak;CO2R, –COR, –CO2H

meta-Directing Deactivators: –NO₂, –CN, –CHO, –⁠CO₂R, –COR, –CO₂H

All meta-directing substituents are deactivating groups. These substituents withdraw electrons from the aromatic ring, making the ring less reactive toward electrophilic substitution. For example, the nitration of nitrobenzene is 100,000 times slower than that of benzene because of the deactivating effect of the nitro group. The first step in an electrophilic aromatic substitution is the addition of an electrophile to form a resonance-stabilized carbocation. The energy diagrams for...

Radical Anti-Markovnikov Addition to Alkenes: Mechanism

Radical Anti-Markovnikov Addition to Alkenes: Mechanism

The reaction of hydrogen bromide with alkenes in the presence of hydroperoxides or peroxides proceeds via anti-Markovnikov addition. The radical chain reaction comprises initiation, propagation, and termination steps.
The mechanism starts with chain initiation, which involves two steps. In the first chain initiation step, a weak peroxide bond is homolytically cleaved upon mild heating to form two alkoxy radicals. In the second initiation step, a hydrogen atom is abstracted by the alkoxy...

ortho–para-Directing Deactivators: Halogens

ortho–para-Directing Deactivators: Halogens

Halogens are ortho–para directors. They are more electronegative than carbon. Therefore, as ring substituents, they can withdraw electrons through the inductive effect and deactivate the aromatic ring towards electrophilic substitution. Halogens also have an electron-donating resonance effect on the ring, which influences the orientation of the incoming electrophile. If an electrophile attacks at the ortho or the para position, the halogen donates electrons and stabilizes the intermediate...