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| Titel |
Validation of ACE and OSIRIS ozone and NO2 measurements using ground-based instruments at 80° N |
| VerfasserIn |
C. Adams, K. Strong, R. L. Batchelor, P. F. Bernath, S. Brohede, C. Boone, D. Degenstein, W. H. Daffer, J. R. Drummond, P. F. Fogal, E. Farahani, C. Fayt, A. Fraser, F. Goutail, F. Hendrick, F. Kolonjari, R. Lindenmaier, G. Manney, C. T. McElroy, C. A. McLinden, J. Mendonca, J.-H. Park, B. Pavlovic, A. Pazmino, C. Roth, V. Savastiouk, K. A. Walker, D. Weaver, X. Zhao |
| 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 ; 5, no. 5 ; Nr. 5, no. 5 (2012-05-04), S.927-953 |
| Datensatznummer |
250002858
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| Publikation (Nr.) |
 copernicus.org/amt-5-927-2012.pdf |
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| Zusammenfassung |
| The Optical Spectrograph and Infra-Red Imager System (OSIRIS) and the
Atmospheric Chemistry Experiment (ACE) have been taking measurements from
space since 2001 and 2003, respectively. This paper presents intercomparisons
between ozone and NO2 measured by the ACE and OSIRIS satellite
instruments and by ground-based instruments at the Polar Environment
Atmospheric Research Laboratory (PEARL), which is located at Eureka, Canada
(80° N, 86° W) and is operated by the Canadian Network for
the Detection of Atmospheric Change (CANDAC). The ground-based instruments
included in this study are four zenith-sky differential optical absorption
spectroscopy (DOAS) instruments, one Bruker Fourier transform infrared
spectrometer (FTIR) and four Brewer spectrophotometers. Ozone total columns
measured by the DOAS instruments were retrieved using new Network for the
Detection of Atmospheric Composition Change (NDACC) guidelines and agree to
within 3.2%. The DOAS ozone columns agree with the Brewer
spectrophotometers with mean relative differences that are smaller than
1.5%. This suggests that for these instruments the new NDACC data
guidelines were successful in producing a homogenous and accurate ozone
dataset at 80° N. Satellite 14–52 km ozone and 17–40 km NO2
partial columns within 500 km of PEARL were calculated for ACE-FTS Version
2.2 (v2.2) plus updates, ACE-FTS v3.0, ACE-MAESTRO (Measurements of Aerosol
Extinction in the Stratosphere and Troposphere Retrieved by Occultation) v1.2
and OSIRIS SaskMART v5.0x ozone and Optimal Estimation v3.0 NO2 data
products. The new ACE-FTS v3.0 and the validated ACE-FTS v2.2 partial columns
are nearly identical, with mean relative differences of 0.0 ± 0.2%
and −0.2 ± 0.1% for v2.2 minus
v3.0 ozone and NO2, respectively. Ozone
columns were constructed from 14–52 km satellite and 0–14 km ozonesonde
partial columns and compared with the ground-based total column measurements.
The satellite-plus-sonde measurements agree with the ground-based ozone total
columns with mean relative differences of 0.1–7.3%. For NO2, partial
columns from 17 km upward were scaled to noon using a photochemical model.
Mean relative differences between OSIRIS, ACE-FTS and ground-based
NO2 measurements do not exceed 20%. ACE-MAESTRO measures more
NO2 than the other instruments, with mean relative differences of
25–52%. Seasonal variation in the differences between
NO2 partial columns is
observed, suggesting that there are systematic errors in the measurements
and/or the photochemical model corrections. For
ozone spring-time measurements, additional coincidence criteria based on
stratospheric temperature and the location of the polar vortex were found to
improve agreement between some of the instruments. For ACE-FTS v2.2 minus
Bruker FTIR, the 2007–2009 spring-time mean relative difference improved
from −5.0 ± 0.4% to −3.1 ± 0.8% with the dynamical
selection criteria. This was the largest improvement, likely because both
instruments measure direct sunlight and therefore have well-characterized
lines-of-sight compared with scattered sunlight measurements. For NO2,
the addition of a ±1° latitude coincidence criterion improved
spring-time intercomparison results, likely due to the sharp latitudinal
gradient of NO2 during polar sunrise. The differences between satellite
and ground-based measurements do not show any obvious trends over the
missions, indicating that both the ACE and OSIRIS instruments continue to
perform well. |
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