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| Titel |
Discrimination of aerosol species by correlated lidar and sunphotometer measurements in the Paris megacity suburban area |
| VerfasserIn |
J. Totems, P. Royer, P. Chazette, M. Haeffelin, C. Pietras |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250063641
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| Zusammenfassung |
| This unprecedented study of daytime measurements performed over 3 years (2007-2010)
with a robust commercial lidar (ALS 450, www.leosphere.com) installed ~20 km south of
Paris (instrumented site of Palaiseau - SIRTA) and coupled with a sunphotometer, shows that
differing optical properties allow the discrimination of several families in the observed
aerosol content. While the lidar performed resolved measurements in the atmospheric column
at 355 nm wavelength every 5 minutes with a vertical resolution of 15 m, the sunphotometer,
which is part of the AERONET network, provided the spectral atmospheric transmittance
between 340 and 1020 nm. Correlating the lidar and sunphotometer measurements opens
interesting prospects for the detection of the main pollution events around the megacity of
Paris. The Lidar Ratio (LR), the depolarization ratio (Ï) and the Angström coefficient (A)
characterize specific aerosol optical properties and may sign their origins. They are retrieved
from the instruments on clear days, as an average in the tropospheric column over a
few minutes. Scatter plots along these parameters show that Parisian pollutants
dominate the scene, with familiar properties corresponding to previous findings
(LR~70 sr-1, A~1). In some meteorological conditions, aerosol pollutants are
observed which present different optical properties. We discuss these results in
the light of known events in the survey time-line and conclude on the capabilities
for identification of aged aerosols trapped within long range transport processes. |
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