First simultaneous space measurements of atmospheric pollutants in the boundary layer from IASI: A case study in the North China Plain

In this paper we investigate a severe pollution episode that occurred in Beijing, Tianjin, and the Hebei province in January 2013. The episode was caused by the combination of anthropogenic emissions and a high‐pressure system that trapped pollutants in the boundary layer. Using IASI (Infrared Atmospheric Sounding Interferometer) satellite measurements, high concentrations of key trace gases such as carbon monoxide (CO), sulfur dioxide (SO 2 ), and ammonia (NH 3 ) along with ammonium sulfate aerosol ((NH 4 ) 2 SO 4 ) are found. We show that IASI is able to detect boundary layer pollution in case of large negative thermal contrast combined with high levels of pollution. Our findings demonstrate that anthropogenic key pollutants, such as CO and SO 2 , can be monitored by IASI in the North China Plain during wintertime in support of air quality evaluation and management.