Satellite monitoring of ammonia: from point sources to long-term trends

IASI satellite NH3 measurements are used to identify, categorise and quantify world’s NH3 emission hotspots. In particular, using spatial oversampling and supersampling techniques, we are able to track-down more than 500 localized point sources of agricultural, industrial – fertilizer, coking, soda ash, geothermal and explosives industries-, urban and natural origin. Calculated satellite-based emissions suggest a drastic underestimation of point sources in bottom-up inventories, especially those of industrial emitters. Using IASI dataset for temporal analysis reveals rapid shifts in anthropogenic activities and distinct pattern in long-term trends.

The IASI mission consists of a suite of three infrared sounders providing today over 11 years of consistent global measurements (from end of 2007 up to now). In this work we use the version 3 of the ANNI retrieval algorithm (Van Damme et al., 2017; Franco et al., 2018), recently validated with in-situ columns (Guo et al., in prep.).