Monitoring compliance with sulfur content regulations of shipping fuel by in situ measurements of ship emissions

Abstract

Abstract. In 1997 the International Maritime Organisation (IMO) adopted MARPOL Annex VI to prevent air pollution by shipping emissions. It regulates, among other issues, the sulfur content in shipping fuels, which is transformed into the air pollutant sulfur dioxide (SO 2 ) during combustion. Within designated Sulfur Emission Control Areas (SECA), the sulfur content was limited to 1 %, and on 1 January 2015, this limit was further reduced to 0.1 %. Here we present the set-up and measurement results of a permanent ship emission monitoring site near Hamburg harbour in the North Sea SECA. Trace gas measurements are conducted with in situ instruments and a data set from September 2014 to January 2015 is presented. By combining measurements of carbon dioxide (CO 2 ) and SO 2 with ship position data, it is possible to deduce the sulfur fuel content of individual ships passing the measurement station, thus facilitating the monitoring of compliance of ships with the IMO regulations. While compliance is almost 100 % for the 2014 data, it decreases only very little in 2015 to 95.4 % despite the much stricter limit. We analysed more than 1400 ship plumes in total and for months with favourable conditions, up to 40 % of all ships entering and leaving Hamburg harbour could be checked for their sulfur fuel content.

Attribution of atmospheric sulfur dioxide over the English Channel to dimethyl sulfide and changing ship emissions

“…Our FSC estimates illustrate a fairly similar decreasing trend to that observed near the Hamburg harbor (Kattner et al, 2015). The mean FSC value at PPAO is approximately half of what was estimated by Kattner et al (2015) for the year 2014 and is comparable to their estimate for 2015.…”

“…The mean FSC value at PPAO is approximately half of what was estimated by Kattner et al (2015) for the year 2014 and is comparable to their estimate for 2015. However, our observations are different in several aspects.…”

“…The number of large container ships entering Plymouth Sound is proportionally much lower than near Hamburg. Because the distances between ships and PPAO were not fixed (as opposed to spatially restricted sampling locations in Kattner et al, 2015, andBeecken et al, 2015), plumes observed at our site were usually more dilute and variable in duration. This variability made plume identification more challenging.…”

“…Apparent FSC is computed from coincidental SO 2 and CO 2 plume heights as well as plume areas (N = 245) following Kattner et al (2015). To account for clock drift between the computers that recorded the SO 2 and CO 2 data, we allowed the times of the SO 2 and CO 2 peaks to differ by up to 1 min.…”

“…Kattner et al (2015) reported large reductions of SO 2 in ship plumes from 2014 to 2015 near the mouth of the Hamburg harbor on the river Elbe, which is about 100 km away from the North Sea. Using the SO 2 : CO 2 ratio in ship plumes, they found a high compliance rate of ∼ 95 % after the stricter regulation in January 2015.…”