From ship smokestack to global air pollution: bridging the scales to better constrain ship NOx emissions from space

Seagoing ships combust massive amounts of
marine heavy fuel, which leads to significant
emissions of nitrogen oxides (NOx = NO +
NO2), important precursors for ozone (O3)
and particulate matter in the lower marine
atmosphere. Ship NOx emissions are high, but
also highly uncertain: recent estimates suggest
that they represent between 15 to 30% of
global NOx emissions (e.g. Eyring et al., 2010).
Because most of the ship emissions occur within
400 km of land (Corbett et al., 1999), it is
important to understand how global shipping
affects atmospheric composition and how it
affects air quality in densely populated coastal
regions. These enhanced NO2 concentrations
along shipping lanes from Europe, via the
Middle East, to eastern Asia can be observed
from space illustrating the significance
and global character of ship pollution.