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| Titel |
Long-term MAX-DOAS measurement of trace gases and aerosol in the
Environmental Research Station Schneefernerhaus |
| VerfasserIn |
Zhuoru Wang, Nan Hao, Francois Hendrick, Michel Van Roozendael, Robert Holla, Pieter Valks |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250135042
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| Publikation (Nr.) |
 EGU/EGU2016-15837.pdf |
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| Zusammenfassung |
| The Environmental Research Station Schneefernerhaus (Umwelt Forschungsstation
Schneefernerhaus, UFS) is located immediately under the summit of Zugspitze (2962 m), the
highest mountain of Germany, at a height of 2650 m. The UFS is a rare observation site in
Germany with mostly clean and unpolluted air. It is ideal for both stratospheric composition
measurements and trace gas measurements in the free-troposphere. It is optimal for detecting
pollution events in the free-troposphere, which are indications of short- or long-range
transport of air pollutants.
A MAX-DOAS instrument has been working in the UFS since February 2011. With the
zenith spectrum of each cycle used as the reference, the differential slant column densities
(DSCDs) of trace gases are calculated from the spectra with Differential Optical Absorption
Spectroscopy (DOAS) method. The DSCDs of both O4 and NO2 are calculated in
two different wavelength intervals, 338-370 nm in the UV region and 440-490
nm in the VIS region. For HCHO and HONO, optimal fitting windows have been
determined in the UV region. A retrieval algorithm, based on the radiative transfer
model LIDORT and the optimal estimation technique, is used to provide information
on the vertical profiles and vertical column densities (VCDs) of aerosol and trace
gases.
Meanwhile, zenith-sky radiance spectra during twilight hours are analyzed using DOAS
method to derive the total vertical column densities (VCDs) of O3 and NO2. A zenith
spectrum measured in the noon of a summer day was chosen as the reference spectrum. The
slant column densities (SCDs) of O3 and NO2, which are the direct product of the DOAS
analysis, are then converted into VCDs using the air mass factors (AMFs) derived by
radiative transfer calculations.
This work presents the results of the MAX-DOAS measurement in the UFS from 2012 to
2015, including aerosol (derived from O4 measurement), NO2, HCHO, and HONO, etc. The
vertical profiles as well as the seasonal and diurnal variation patterns of tropospheric aerosol
and trace gases will be shown. The total VCDs of O3 and NO2, as well as a comparison
between MAX-DOAS measurement and satellite measurement will also be shown. In the
end, high NO2 episodes in the UFS due to long range transport of air pollutants will be
presented. |
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