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| Titel |
Intercomparison of daytime stratospheric NO2 satellite retrievals and model simulations |
| VerfasserIn |
M. Belmonte Rivas, P. Veefkind, F. Boersma, P. Levelt, H. Eskes, J. Gille |
| 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. 7 ; Nr. 7, no. 7 (2014-07-22), S.2203-2225 |
| Datensatznummer |
250115853
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| Publikation (Nr.) |
 copernicus.org/amt-7-2203-2014.pdf |
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| Zusammenfassung |
| This paper evaluates the agreement between stratospheric NO2
retrievals from infrared limb sounders (Michelson Interferometer for Passive Atmospheric
Sounding (MIPAS) and High Resolution Dynamics Limb Sounder (HIRDLS)) and solar
UV/VIS backscatter sensors (Ozone Monitoring Instrument (OMI), Scanning Imaging Absorption
Spectrometer for Atmospheric Cartography (SCIAMACHY) limb and nadir) over the
2005–2007 period and across the seasons. The observational
agreement is contrasted with the representation of NO2
profiles in 3-D chemical transport models such as the Whole
Atmosphere Community Climate Model (WACCM) and TM4. A conclusion
central to this work is that the definition of a reference for
stratospheric NO2 columns formed by consistent agreement
among SCIAMACHY, MIPAS and HIRDLS limb records (all of which agree
to within 0.25 × 1015 molecules cm−2 or better
than 10%) allows us to draw attention to relative errors in
other data sets, e.g., (1) WACCM overestimates NO2
densities in the extratropical lower stratosphere, particularly in the
springtime and over
northern latitudes by up to 35% relative to limb observations,
and (2) there are remarkable discrepancies between stratospheric
NO2 column estimates from limb and nadir techniques, with
a characteristic seasonally and latitudinally dependent pattern. We find
that SCIAMACHY nadir and OMI stratospheric columns show overall biases of
−0.5 × 1015 molecules cm−2 (−20%) and
+0.6 × 1015 molecules cm−2 (+20%)
relative to limb observations, respectively. It is argued that additive biases in
nadir stratospheric columns are not expected to affect tropospheric
retrievals significantly, and that they can be attributed to errors
in the total slant column density, related either to algorithmic or
instrumental effects. In order to obtain accurate and long-term time
series of stratospheric NO2, an effort towards the harmonization
of currently used differential optical absorption spectroscopy (DOAS)
approaches to nadir retrievals becomes essential, as well as their
agreement to limb and ground-based observations, particularly now
that limb techniques are giving way to nadir observations as the
next generation of climate and air quality monitoring instruments pushes forth. |
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