Partikelemissionen des Schiffsverkehrs und deren Einfluss auf das Aerosol der maritimen Grenzschicht - Ergebnisse der QUANTIFY SHIPS Studie 2007

Kurzfassung

The investigation of the impact of shipping emissions on the atmosphere is important, since shipping represents a major element of international transportation. This study deals with emission data from ships which also include their atmospheric transformation The properties of aerosol particles from emission during plume processing in the atmosphere to a scale of ship corridors are characterised. The quantity of additional particles in the marine boundary layer over shipping corridors is determined. The change of the optical properties and the additional amount of potential cloud condensation nuclei in the marine boundary layer are subject to investigation. Within the QUANTIFY SHIPS field study in June 2007, particle emissions from ship engines and their atmospheric transformation were studied. Airborne measurements of a single ship plume were combined with simultaneous measurements of fresh exhaust onboard the source vessel. Additionally, aged aerosol in highly frequented sea lanes was measured. Onboard the research aircraft DLR Falcon 20E, a set of instruments was operated for the in situ measurements of secondary volatile aerosol, primary combustion particles, marine background aerosol, trace gases and meteorological parameters. The changing properties of fresh to aged aerosol were characterised using measurements in the dispersing plume and in highly frequented ship corridors. An effective emission index of (2,3 ± 0,9)1016 (kg fuel)-1 for total aerosol, (1,8 ± 1,1)1016 (kg fuel)-1 for non-volatile Aitkenmode aerosol and (0,25 ± 0,21)1016 (kg fuel)-1 for accumulation mode aerosol was found. The additional contribution of particles from shipping to the aerosol budget of the polluted marine boundary layer was determined to be 54% to 68% for total aerosol, 68% to 85% for non-volatile Aitken mode aerosol and 38% to 54% for accumulation mode aerosol. It is determined, that the aerosol optical depth of shipping is 26% of the aerosol optical depth of the clean marine boundary layer under dry conditions, 35% at a relative humidity of 90% and 36% at a relative humidity of 95%. The potential cloud condensation nuclei fraction of total emissions from shipping was estimated to be 2.5% at a supersaturation of 0.1% and 39% at a supersaturation of 0.3%. The results of this study were presented during the European Aerosol Conference (EAC) 2009.