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| Titel |
A kite-based approach for water-vapor lidar calibration and application to multi-platform intercomparison in the Western Mediterranean during ChArMEx/ADRIMED |
| VerfasserIn |
Julien Totems, Patrick Chazette, François Dulac, Sahar Hassanzadeh |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250110451
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| Publikation (Nr.) |
 EGU/EGU2015-10448.pdf |
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| Zusammenfassung |
| In the framework of the ADRIMED campaign included in the ChArMEx (Chemistry Aerosol
Mediterranean Experiment) research program, performed in June 2013 in the western
Mediterranean, the mobile Water vapor Aerosol LIdar (WALI) developed by LSCE was
deployed at Cap d’en Font on the island of Menorca (Spain). Alongside an elastic backscatter
channel, it features depolarization, N2- and H2O-Raman channels, the two latter yielding
profiles of atmospheric water vapor mixing ratio (WVMR). The water content thus provided
by the lidar is essential to validate models or satellite water vapor products for
meteorological purposes. It also proved to be very helpful in characterizing particle
types and sources, especially for the multi-layer situations observed during the
ChArMEx/ADRIMED special observation period. Beforehand, however, a precise calibration
of the WVMR had to be done on-site. Balloon rawindsoundings performed by CNES
were available about 10 km off-site on Saint-Lluis aerodrome or 100 km away on
Majorca for this purpose, but strong inhomogeneities in the WVMR observed under
2 km altitude prevent an accurate calibration and the determination of the lidar
overlap factor, which biases WVMR retrieval under 300 m. Instead, we propose
the use of a lightweight Pressure-Temperature-Relative Humidity (PTU) sound
carried under a simple kite to perform a co-localized sounding. Modern kites indeed
combine the advantages of an easy deployment and the possibility of longer, more
precise soundings in the low troposphere. After showing that this approach leads
to calibration with less than 2% error from 80 m altitude, we validate it against
rawindsounding WVMR profiles, with very good agreement at high altitude. We also
present further comparisons between the lidar-derived WVMR and the one given by
meteorological model reanalyses (AROME, ECMWF) or satellite inversion products (IASI). |
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