Airborne monitoring of compliance to sulfur emission regulations by ocean-going vessels in the Belgian North Sea area

Air pollution from fossil fuel powered ocean-going vessels (OGVs) is responsible for various environmental and human health issues worldwide. Specifically for sulfur oxides (SOx), from 2010 onwards, stricter standards came into force regarding the maximum allowable fuel sulfur content (FSC) in marine fuels in the European Sulfur Emission Control Area (SECA). A method was developed for the airborne monitoring of OGVs to evaluate their compliance by equipping the Belgian coastguard aircraft with a sniffer sensor. The sensor allows a highly accurate FSC determination based on real-time CO2 and SO2 measurements in the smoke plume of OGVs. For 5 years the aircraft collected the largest set of airborne emission measurement data from OGVs as of today. This article demonstrates the effectiveness and reliability of the airborne monitoring methodology in an operational setup for targeting ship inspections in ports and a more efficient impact monitoring of shipping on air quality.