All posts in “dust monitoring”

Playa Dust Playing a Role in Ozone Formation

North American playas are large dust emitters. Dotting the deserts of the Southwestern United States, these dry lake beds are highly saline from the concentration of salts following evaporation. These salt deposits can become entrained in the air when winds scour the dried lakebed. The resulting saline dust has a high fraction of halogenated compounds, primarily those containing chlorine. When the chlorine-containing aerosols (the dust that remains suspended in the atmosphere) mix with nitrogen oxides (primarily dinitrogen pentoxide), a gas called nitryl chloride (ClNO2) is produced. Sunlight interacts with  ClNO2, breaking it apart into chlorine radicals that participate in the formation of tropospheric ozone.

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