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Characterizing signatures of shipping emissions with satellite measurements of nitrogen dioxide

Show simple item record 2021-08-27T12:51:51Z 2021-08-27T12:51:51Z 2021-08-27
dc.title Characterizing signatures of shipping emissions with satellite measurements of nitrogen dioxide en
ethesis.faculty Matemaattis-luonnontieteellinen tiedekunta fi
ethesis.faculty Faculty of Science en
ethesis.faculty Matematisk-naturvetenskapliga fakulteten sv
ethesis.faculty.URI Helsingin yliopisto fi University of Helsinki en Helsingfors universitet sv
dct.creator Suhonen, Elli
dct.issued 2021
dct.abstract International shipping is globally a major source of atmospheric nitrogen oxides (NOx). It has been widely recognized that these emissions have negative effects on maritime air quality and human health. For a long time, shipping was the least regulated NOx emission source, but now first regulations for ship exhaust NOx emissions started as of January 2021. Shipping emissions must be monitored so the obedience of these regulations can be followed. Different measurement techniques are developed to address the problems related to shipping emission monitoring. The purpose of this thesis is to demonstrate how tropospheric nitrogen dioxide (NO2) concentration measurements by TROPOspheric Monitoring Instrument (TROPOMI) onboard Copernicus Sentinel 5 Precursor (S5P) satellite can be used to characterize signatures of shipping emissions. The capability of TROPOMI to detect busy shipping lanes and port areas was first tested with a large study area of the whole Eastern Mediterranean Sea. Analysis was supported with shipping emission data inventory from the Ship Traffic Assessment Model (STEAM). Results showed elevated NO2 concentrations close to major port areas, especially if the dominant wind direction on the water area was from the continent. These elevated concentrations were most likely a result of both transported urban emissions and shipping emissions. STEAM and TROPOMI grid cell comparison was done over the busiest shipping lane area over the open sea, and the results showed that if the monthly summed shipping emission amount was either small or very large, the signal of shipping emissions was affected by background concentrations. More detailed shipping emission study was done at port Piraeus and the surrounding sea area. There, satellite measurement analysis was done by selecting three smaller study areas for comparison, one over the city of Athens, the second one close to the port Piraeus and the third one over the open sea. Relation between the satellite observations of NO2 and modelled shipping emissions of NOx was obtained in the study area that was over the open sea, the center of the area being 35 km from the coast. The signal of shipping emissions was not detected close to the port, most likely because of the influence of other emission sources. Lastly, spring and summer 2020 were analysed separately in more detail, as they were included in the overall study period of this thesis but the air pollution patterns at that time were affected by the extraordinary COVID-19 pandemic restrictions. The results showed unusually small average NO2 concentrations over the city of Athens during spring 2020. Meteorological observations from that time period did not show anything that could fully explain the decrease. Observations over the sea close to Piraeus showed no clear difference between 2019 and 2020 average concentrations, so the pandemic possibly had only a minor impact on the shipping emissions in the port area. en
dct.subject satellite measurements
dct.subject nitrogen dioxide
dct.subject shipping
ethesis.isPublicationLicenseAccepted true
ethesis.language englanti fi
ethesis.language English en
ethesis.language engelska sv
ethesis.thesistype pro gradu -tutkielmat fi
ethesis.thesistype master's thesis en
ethesis.thesistype pro gradu-avhandlingar sv
dct.identifier.ethesis E-thesisID:1389fa46-78d6-4524-80cf-3641cee867d3
dct.identifier.urn URN:NBN:fi:hulib-202108273579
dc.type.dcmitype Text
ethesis.facultystudyline Meteorologia fi
ethesis.facultystudyline Meteorology en
ethesis.facultystudyline Meteorologi sv
ethesis.mastersdegreeprogram Ilmakehätieteiden maisteriohjelma fi
ethesis.mastersdegreeprogram Master's Programme in Atmospheric Sciences en
ethesis.mastersdegreeprogram Magisterprogrammet i atmosfärsvetenskaper sv

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