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| Titel |
Spatial and temporal variability in Athens observed by MAX-DOAS |
| VerfasserIn |
Andreas Richter, Myrto Gratsea, Folkard Wittrock, John P. Burrows, Mihalis Vrekoussis, Evangelos Gerasopoulos |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250092054
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| Publikation (Nr.) |
 EGU/EGU2014-6380.pdf |
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| Zusammenfassung |
| Multi Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) observations
provide valuable information on tropospheric absorber amounts and their vertical distribution
by analysing measurements of scattered sun-light taken at different elevation angles. This
information can be used to estimate surface mixing ratios, mixing heights, and tropospheric
columns. Recent developments in instrumentation now also allow scanning in the
azimuthal direction, giving some insight into the horizontal variability of trace gas
distributions. This is of particular interest in the vicinity of localised sources and in
cities.
In this study, 18 months of MAX-DOAS observations in Athens (38.05°N, 23.9°E) have
been analysed for tropospheric NO2 amounts. The instrument is operated at the NOA
observatory on Penteli Hill at the outskirts of Athens in about 500 m altitude. From this point,
8 viewing directions covering various locations of interest including rural areas,
the city suburbs and the city centre are scanned routinely, and strongly varying
temporal and spatial variations can be observed. The data show clear signals of the
weekly cycle, pollution reduction during summer break and repeating spatial patterns
linked to meteorology and the build-up and transport of NO2 from the main city
area.
In addition to these interesting geophysical findings, the observed gradients also pose
challenging questions with respect to the assumptions usually made in the analysis of
MAX-DOAS measurements, and these will be discussed as well. |
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