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Las intrusiones de aire estratosférico promueven la formación de nuevas partículas a escala global
Jiaoshi Zhang1, Xianda Gong1, Ewan Crosbie2,3
1Center for Aerosol Science and Engineering, Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, USA.
Science (New York, N.Y.)
|July 11, 2024
Resumen
Las intrusiones de aire estratosférico desencadenan la formación de nuevas partículas en la troposfera libre. Este proceso, impulsado por niveles elevados de dióxido de azufre y radicales hidroxilo, crea núcleos de condensación de nubes.
Área de la Ciencia:
- Química de la atmósfera
- Ciencia de los aerosoles
- Ciencias del clima
Sus antecedentes:
- La formación de nuevas partículas en la troposfera libre es una fuente primaria de núcleos de condensación de nubes (CCN) a nivel mundial.
- La comprensión actual sugiere que la formación de partículas ocurre principalmente en las salidas de nubes convectivas.
Objetivo del estudio:
- Investigar un mecanismo alternativo para la formación de nuevas partículas en la troposfera libre.
- Identificar el papel de las intrusiones de aire estratosférico en la producción de partículas atmosféricas.
Principales métodos:
- Análisis de los datos de las observaciones globales.
- Identificación de eventos de intrusión de aire en la estratosfera.
- Correlación entre la composición atmosférica (SO2, OH, ozono) y la formación de partículas.
Principales resultados:
- Las intrusiones de aire estratosférico conducen a la mezcla de aire estratosférico rico en ozono con aire troposférico húmedo.
- Esta mezcla da lugar a concentraciones elevadas de radicales hidroxilo (OH).
- Los altos niveles de dióxido de azufre (SO2) y OH cerca de la tropopausa aumentan la formación de ácido sulfúrico, impulsando la formación de partículas.
Conclusiones:
- Las intrusiones de aire estratosférico representan un mecanismo significativo y generalizado para la formación de nuevas partículas en la troposfera libre de latitudes medias.
- Esta vía contribuye sustancialmente al presupuesto global de la CCN.
- Los hallazgos desafían el punto de vista prevaleciente al destacar una vía de formación de partículas no convectiva.
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