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| Titel |
A mobile differential absorption lidar to measure sub-hourly fluctuation of tropospheric ozone profiles in the Baltimore–Washington, D.C. region |
| VerfasserIn |
J. T. Sullivan, T. J. McGee, G. K. Sumnicht, L. W. Twigg, R. M. Hoff |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1867-1381
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 7, no. 10 ; Nr. 7, no. 10 (2014-10-15), S.3529-3548 |
| Datensatznummer |
250115934
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| Publikation (Nr.) |
 copernicus.org/amt-7-3529-2014.pdf |
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| Zusammenfassung |
| Tropospheric ozone profiles have been retrieved from the new ground-based
National Aeronautics and Space Administration (NASA) Goddard Space Flight
Center TROPospheric OZone DIfferential Absorption Lidar (GSFC TROPOZ DIAL) in
Greenbelt, MD (38.99° N, 76.84° W, 57 m a.s.l.), from
400 m to 12 km a.g.l. Current atmospheric satellite instruments cannot
peer through the optically thick stratospheric ozone layer to remotely sense
boundary layer tropospheric ozone. In order to monitor this lower ozone more
effectively, the Tropospheric Ozone Lidar Network (TOLNet) has been
developed, which currently consists of five stations across the US. The GSFC
TROPOZ DIAL is based on the DIAL technique,
which currently detects two wavelengths, 289 and 299 nm, with multiple
receivers. The transmitted wavelengths are generated by focusing the output
of a quadrupled Nd:YAG laser beam (266 nm) into a pair of Raman cells,
filled with high-pressure hydrogen and deuterium, using helium as buffer gas.
With the knowledge of the ozone absorption coefficient at these two
wavelengths, the range-resolved number density can be derived. An interesting
atmospheric case study involving the stratospheric–tropospheric exchange
(STE) of ozone is shown, to emphasize the regional importance of this
instrument as well as to assess the validation and calibration of data. There
was a low amount of aerosol aloft, and an iterative aerosol correction has
been performed on the retrieved data, which resulted in less than a 3 ppb
correction to the final ozone concentration. The retrieval yields an
uncertainty of 16–19% from 0 to 1.5 km, 10–18% from 1.5 to 3 km, and
11–25% from 3 to 12 km according to the relevant aerosol concentration
aloft. There are currently surface ozone measurements hourly and ozonesonde
launches occasionally, but this system will be the first to make routine
tropospheric ozone profile measurements in the Baltimore–Washington, D.C. area. |
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