Reactive nitrogen-driven atmospheric multiphase buffering induces unintended concomitant pollution.

Area of Science:

• Atmospheric Chemistry and Physics
• Environmental Science
• Aerosol Science

Background:

• Atmospheric multiphase buffering capacity is a key aerosol property affecting climate and public health.
• The role of atmospheric multiphase buffering in air pollution, particularly Concomitant Pollution, is not well understood.
• Reactive nitrogen (Nr) plays a significant role in atmospheric processes.

Purpose of the Study:

• To investigate the link between reactive nitrogen-driven atmospheric multiphase buffering and Concomitant Pollution.
• To elucidate the mechanisms by which gaseous pollutants transform into particulate pollution under buffering conditions.
• To assess the global distribution and drivers of NH4+/NH3-induced Concomitant Pollution.

Main Methods:

• Analysis of four years of continuous atmospheric observation data.
• Conducting laboratory experiments to simulate multiphase buffering processes.
• Global-scale modeling to analyze pollution patterns and contributing factors.

Main Results:

• Reactive nitrogen (Nr) buffering induces Concomitant Pollution by partitioning gaseous pollutants into aerosol aqueous phases.
• NH4+/NH3-induced Concomitant Pollution is most intense in South Asia during winter and in North America, Europe, and East Asia during summer.
• Anthropogenic emissions, especially ammonia (NH3), are a greater driver of Concomitant Pollution than meteorological factors.

Conclusions:

• Atmospheric multiphase buffering, particularly driven by reactive nitrogen, is a significant source of unintended Concomitant Pollution.
• Global ammonia emissions are a primary driver of Concomitant Pollution, posing an urgent air quality challenge.
• Understanding and mitigating NH3 emissions are crucial for addressing Concomitant Pollution.