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| Titel |
Atomic oxygen retrievals in the MLT region from SCIAMACHY nightglow limb measurements |
| VerfasserIn |
O. Lednyts'kyy, C. von Savigny, K.-U. Eichmann, M. G. Mlynczak |
| 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 ; 8, no. 3 ; Nr. 8, no. 3 (2015-03-04), S.1021-1041 |
| Datensatznummer |
250116198
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| Publikation (Nr.) |
 copernicus.org/amt-8-1021-2015.pdf |
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| Zusammenfassung |
| Vertical distributions of atomic oxygen concentration ([O]) in the mesosphere
and lower thermosphere (MLT) region were retrieved from sun-synchronous
SCIAMACHY/Envisat (SCanning Imaging Absorption spectroMeter for Atmospheric
CHartographY on board the Environmental
Satellite) limb measurements of the oxygen 557.7 nm
green line emission in the terrestrial nightglow. A band pass filter
was applied to eliminate contributions from other emissions, the impact
of measurement noise and auroral activity. Vertical volume emission rate
profiles were retrieved from integrated limb-emission rate profiles under
the assumption that each atmospheric layer is horizontally homogeneous
and absorption and scattering can be neglected. The radiative transfer
problem was solved using regularized total least squares minimization
in the inversion procedure. Atomic oxygen concentration
profiles were retrieved from data collected for altitudes in the range
85–105 km with approximately 4 km vertical
resolution during the time period from August 2002 to April 2012
at approximately 22:00 local time. The retrieval of [O]
profiles was based on the generally accepted two-step Barth transfer scheme
including consideration of quenching processes and the use of different
available sources of temperature and atmospheric density profiles.
A sensitivity analysis was performed for the retrieved [O] profiles
to estimate maximum uncertainties assuming independent contributions of
uncertainty components. Errors in photochemical model parameters depending
on temperature uncertainties and random errors of model parameters
contribute less than 50% to the overall [O] retrieval error.
The retrieved [O] profiles were compared with reference [O]
profiles provided by SABER/TIMED (Sounding of the Atmosphere using Broadband Emission Radiometry
instrument on board the Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics satellite) or by the NRLMSISE-00
(Naval Research Laboratory Mass Spectrometer and Incoherent Scatter radar Extended model, year: 2000) and SD-WACCM4 (Whole Atmosphere Community
Climate Model with Specified Dynamics, version 4).
A comparison of the retrieved [O] profiles with the reference
[O] profiles led to the conclusion that the photochemical model
taking into account quenching of O(1S) by O2, O(3P),
and N2 and the SABER/TIMED model as a source of temperature and density
profiles are the most appropriate choices for our case. The retrieved
[O] profile time series exhibits characteristic seasonal variations
in agreement with satellite observations based on analysis of OH Meinel
band emissions and atmospheric models. A pronounced 11-year solar cycle
variation can also be identified in the retrieved atomic oxygen concentration
time series. |
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