Ship tracks.The Helmholtz-University Young Investigators Group SeaKLIM (Impact of Shipping on Atmosphere and Climate) of the Institute of Atmospheric Physics investigates the environmental impact of ship emissions jointly with the Institute of Environmental Physics of the University of Bremen. According to SeaKLIM calculations, shipping emitted around 800 Mio t CO2 in 2000 and contributed around 2.7% to all anthropogenic CO2 emissions. For nitrogen oxides (NOx) and sulphur dioxide (SO2) emissions, the contribution is around 15% and 8%, respectively.
With data from the satellite sensor SCIAMACHY the SeaKLIM group was able to show the evidence for the importance of ship emissions from space. SCIAMACHY observations clearly show enhanced tropospheric NO2 columns along the major international shipping routes in the Red Sea and over the Indian Ocean. SCIAMACHY is one of the 10 scientific instruments onboard the ESA Environmental Satellite ENVISAT.
Beside nitrogen dioxide shipping also emits sulphur dioxide, which is formed during the combustion process of fuel with high sulphur content. Sulphur dioxide is oxidised to sulphuric acid in the atmosphere, which together with water forms sulphur containing aerosols. Beside negative impacts on air quality and an increase of sun light that is reflected by the Earth, sulphur containing aerosol plays an important role in the formation of clouds as it acts as cloud condensation nuclei. This has consequences on the microphysical and optical properties. An interesting reoccurring phenomenon is the formation of ship tracks. To study the full chain of impact from ship emissions on atmosphere and climate is the aim of the SeaKLIM group.