comparison of vlt/x-shooter oh and o2 rotational temperatures with consideration of timed/saber emission and temperature profiles
Clicks: 87
ID: 226563
2016
Article Quality & Performance Metrics
Overall Quality
Not rated
Combines reader engagement with the AI quality analysis. This
article has not been analysed, so there is no overall score —
reader engagement is measured and shown alongside.
Reader Engagement
Steady Performance
25.8
/100
87 views
2 readers
AI Quality Assessment
Not analyzed
Readership in this journal
SteadyRanked #694 of 850 articles by views in Journal of agricultural and food chemistry
Most read
Least read
Bar heights use a square-root scale. Only the 120 most-read articles are drawn; the journal has 850 in total.
Mint this article as an NFT
Not yet mintedCreate a permanent, verifiable on-chain record of this article on the Scimatic Network. The NFT is held in your Journament account, and you can withdraw it to your own wallet at any time.
5
SUSD
one-off · no wallet required
Abstract
Rotational temperatures Trot derived from lines of the
same OH band are an important method to study the dynamics
and long-term trends in the mesopause region near 87 km. To
measure realistic temperatures, the rotational level populations
have to be in local thermodynamic equilibrium (LTE). However, this
might not be fulfilled, especially at high emission altitudes. In
order to quantify possible non-LTE contributions to the OH
Trot as a function of the upper vibrational level
v′, we studied a sample of 343 echelle spectra taken with
the X-shooter spectrograph at the Very Large Telescope at Cerro
Paranal in Chile. These data allowed us to analyse 25 OH
bands in each spectrum. Moreover, we could measure lines of
O2b(0-1), which peaks at about 94 to
95 km, and O2a(0-0) with an emission peak
at about 90 km. The latter altitude is reached in the second
half of the night after a rise of several km because of the
decay of a daytime population of excited O2. Since the
radiative lifetimes for the upper levels of the two O2 bands
are relatively long, the derived Trot are not
significantly affected by non-LTE contributions. These bands are
well suited for a comparison with OH if the differences in
the emission profiles are corrected. For different sample averages,
we made these corrections by using OH emission,
O2a(0-0) emission, and CO2-based
temperature profile data from the multi-channel radiometer SABER on
the TIMED satellite. The procedure relies on differences of
profile-weighted SABER temperatures. For
an O2a(0-0)-based reference profile at
90 km, we found a good agreement of the O2 with the
SABER-related temperatures, whereas the OH temperatures,
especially for the high and even v′, showed significant
excesses with a maximum of more than 10 K for v′ = 8. The exact value depends on the selected lines and molecular
parameters. We could also find a nocturnal trend towards higher
non-LTE effects, particularly for high v′. The amplitude
of these variations can be about 2 K or less, which tends to
be significantly smaller than the total amount of the non-LTE
contributions. The variations revealed may be important for
dynamical studies based on Trot derived from OH
bands with high v′.
| Reference Key |
noll2016atmosphericcomparison
Use this key to autocite in the manuscript while using
SciMatic Manuscript Manager or Thesis Manager
|
|---|---|
| Authors | ;S. Noll;W. Kausch;W. Kausch;S. Kimeswenger;S. Kimeswenger;S. Unterguggenberger;A. M. Jones |
| Journal | Journal of agricultural and food chemistry |
| Year | 2016 |
| DOI |
10.5194/acp-16-5021-2016
|
| URL | |
| Keywords |
Citations
No citations found. To add a citation, contact the admin at info@scimatic.org
Comments
No comments yet. Be the first to comment on this article.