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| Titel |
MODIS Collection 6 aerosol patterns and trends over the greater
Mediterranean region; evaluation and differences with Collection 5.1 |
| VerfasserIn |
Aristeidis K. Georgoulias, Georgia Alexandri, Konstantinos Kourtidis, Jos Lelieveld  , Prodromos Zanis, Vassilis Amiridis |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250143619
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| Publikation (Nr.) |
 EGU/EGU2017-7356.pdf |
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| Zusammenfassung |
| The most recent release of the MODIS (Moderate resolution Imaging Spectroradiometer)
aerosol product is Collection 6 which replaced Collection 5.1. The core parameter of the
MODIS aerosol product is the aerosol optical depth at 550 nm (AOD550). AOD550 retrievals
from the two MODIS sensors aboard the EOS Terra and Aqua satellites have been extensively
used the last fifteen years to examine the sources, the variability of aerosols and
the effect they exert on air quality and climate. Collection 6 is currently used in
studies focusing on the greater Mediterranean region; however, an evaluation of the
Collection 6 AOD550 dataset against ground-based observations and an assessment of its
differences and similarities to the previous widely used Collection 5.1 is missing. In this
work, we present a first comparison of the MODIS/Terra and Aqua Collection 6 and
Collection 5.1 AOD550 data for the greater Mediterranean region (Georgoulias et al.,
2016). It is shown here that Collection 6 AODs are either higher or lower than
Collection 5.1 AODs over different continental areas. On the contrary, over the sea,
Collection 6 AODs are higher almost everywhere (11% for MODIS/Terra and 8% for
MODIS/Aqua). Collection 6 generally retrieves higher AODs than Collection 5.1,
especially for MODIS/Terra. Collection 6 and 5.1 AOD550 data were evaluated against
sunphotometric observations from 23 AERONET stations in the region. It is shown that
Collection 6 exhibits a better agreement with the ground-based data than Collection 5.1.
Our trend analysis shows that the Collection 6 AOD550 data exhibit a statistically
significant negative trend of ∼-0.001/year (∼-0.5%/year) for MODIS/Terra and
∼-0.002/year (∼-1.0%/year) for MODIS/Aqua. Collection 6 AOD550 trends are largely
reduced compared to Collection 5.1 trends by ∼0.003/year for MODIS/Terra. On
the contrary, for MODIS/Aqua the trends have not changed significantly (only by
∼0.0003/year).
*Georgoulias, A.K., Alexandri, G., Kourtidis, K.A., Lelieveld, J., Zanis, P., and
Amiridis, V., Differences between the MODIS Collection 6 and 5.1 aerosol datasets
over the greater Mediterranean region, Atmospheric Environment, 147, 310-319,
doi:10.1016/j.atmosenv.2016.10.014, 2016. |
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