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| Titel |
Constraints on Eurasian ship NOx emissions using OMI NO2 observations and GEOS-Chem |
| VerfasserIn |
Geert C. M. Vinken, Folkert Boersma, Aaron van Donkelaar, Lin Zhang |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250072383
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| Zusammenfassung |
| Ships emit large quantities of nitrogen oxides (NOx = NO + NO2), important precursors for
ozone (O3) and particulate matter formation. Ships burn low-grade marine heavy fuel due to
the limited regulations that exist for the maritime sector in international waters. Previous
studies showed that global ship NOx emission inventories amount to 3.0-10.4 Tg N per year
(15-30% of total NOx emissions), with most emissions close to land and affecting air
quality in densely populated coastal regions. Bottom-up inventories depend on the
extrapolation of a relatively small number of measurements that are often unable to
capture annual emission changes and can suffer from large uncertainties. Satellites
provide long-term, high-resolution retrievals that can be used to improve emission
estimates.
In this study we provide top-down constraints on ship NOx emissions in major European
ship routes, using observed NO2 columns from the Ozone Monitoring Instrument (OMI) and
NO2 columns simulated with the nested (0.5°Ã0.67°) version of the GEOS-Chem chemistry
transport model. We use a plume-in-grid treatment of ship NOx emissions to account for
in-plume chemistry in our model. We ensure consistency between the retrievals and
model simulations by using the high-resolution GEOS-Chem NO2 profiles as a
priori.
We find evidence that ship emissions in the Mediterranean Sea are geographically
misplaced by up to 150 km and biased high by a factor of 4 as compared to the
most recent (EMEP) ship emission inventory. Better agreement is found over the
shipping lane between Spain and the English Channel. We extend our approach and
also provide constraints for major ship routes in the Red Sea and Indian Ocean.
Using the full benefit of the long-term retrieval record of OMI, we present a new
Eurasian ship emission inventory for the years 2005 to 2010, based on the EMEP and
AMVER-ICOADS inventories, and top-down constraints from the satellite retrievals. Our
work shows that satellite retrievals can improve the characterization of emission
locations, magnitudes and trends over sparsely monitored areas such as seas or oceans. |
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