A Study of Rayed Structures in Auroras by Triangulation Methods: 1. Height Profiles of Volume Emission Rate

2021 ◽  
Vol 59 (4) ◽  
pp. 223-230
Author(s):  
B. V. Kozelov ◽  
Zh. V. Dashkevich ◽  
V. E. Ivanov
Keyword(s):  
Emission Rate ◽  
Volume Emission

scholarly journals Variations of the 630.0 nm airglow emission with meridional neutral wind and neutral temperature around midnight

2018 ◽  
Vol 36 (5) ◽  
pp. 1471-1481
Author(s):  
Chih-Yu Chiang ◽  
Sunny Wing-Yee Tam ◽  
Tzu-Fang Chang
Keyword(s):  
Emission Rate ◽  
Local Maximum ◽  
Neutral Wind ◽  
Emission Rates ◽  
Emission Layer ◽  
Neutral Winds ◽  
Neutral Temperature ◽  
Bright Spots ◽  
Different Temperatures ◽  
Volume Emission

Abstract. The ISUAL payload onboard the FORMOSAT-2 satellite has often observed airglow bright spots around midnight at equatorial latitudes. Such features had been suggested as the signature of the thermospheric midnight temperature maximum (MTM) effect, which was associated with temperature and meridional neutral winds. This study investigates the influence of neutral temperature and meridional neutral wind on the volume emission rates of the 630.0 nm nightglow. We utilize the SAMI2 model to simulate the charged and neutral species at the 630.0 nm nightglow emission layer under different temperatures with and without the effect of neutral wind. The results show that the neutral wind is more efficient than temperature variation in affecting the nightglow emission rates. For example, based on our estimation, it would require a temperature change of 145 K to produce a change in the integrated emission rate by 9.8 km-photons cm−3 s−1, while it only needs the neutral wind velocity to change by 1.85 m−1 s−1 to cause the same change in the integrated emission rate. However, the emission rate features a local maximum in its variation with the temperature. Two kinds of tendencies can be seen regarding the temperature that corresponds to the turning point, which is named the turning temperature (Tt) in this study: firstly, Tt decreases with the emission rate for the same altitude; secondly, for approximately the same emission rate, Tt increases with the altitude.

scholarly journals Accounting for O2 absorption in ionospheric UV volume emission rate tomography

2020 ◽  
Vol 17 (6) ◽  
pp. 153-158
Author(s):  
S.A. Kalashnikova ◽  
◽  
E.S. Andreeva ◽  
A.M. Padokhin ◽  
◽  
...  
Keyword(s):  
Emission Rate ◽  
Volume Emission

Long-term variation of OH peak emission altitude and volume emission rate over Indian low latitudes

2016 ◽  
Vol 138-139 ◽  
pp. 161-168 ◽  
Author(s):  
M. Sivakandan ◽  
T.K. Ramkumar ◽  
A. Taori ◽  
Venkateshwara Rao ◽  
K. Niranjan
Keyword(s):  
Emission Rate ◽  
Low Latitudes ◽  
Term Variation ◽  
Volume Emission ◽  
Peak Emission

Two day wave induced variations in the oxygen green line volume emission rate: WINDII observations

1997 ◽  
Vol 24 (9) ◽  
pp. 1127-1130 ◽  
Author(s):  
W. E. Ward ◽  
B. H. Solheim ◽  
G. G. Shepherd
Keyword(s):  
Emission Rate ◽  
Green Line ◽  
Volume Emission ◽  
Wave Induced

Tomographic retrieval of the oxygen infrared atmospheric band with the OSIRIS infrared imager

2004 ◽  
Vol 82 (7) ◽  
pp. 501-515 ◽  
Author(s):  
D A Degenstein ◽  
E J Llewellyn ◽  
N D Lloyd
Keyword(s):  
Spatial Resolution ◽  
Emission Rate ◽  
Two Dimensions ◽  
Line Of Sight ◽  
Two Dimensional ◽  
Retrieval Technique ◽  
The Earth ◽  
Infrared Imager ◽  
Retrieval Scheme ◽  
Volume Emission

The infrared imager (IRI) component of the optical spectrograph and infrared imager system (OSIRIS) onboard the Odin spacecraft provides a set of line-of-sight brightness measurements of the oxygen infrared atmospheric (OIRA) band. This set of measurements is unique in the fact that they are ideal inputs to a two-dimensional retrieval scheme that accurately recovers the volume emission rate of the OIRA band. The retrieval is done simultaneously in two dimensions, the angle along the satellite track and the distance from the centre of the Earth. The latter is easily converted to altitude above the surface of the Earth. In this work, we present the measurement set, the retrieval technique, and some preliminary results. We clearly demonstrate that the OSIRIS infrared imager provides maps of the OIRA band volume emission rate with unprecedented spatial resolution. PACS Nos.: 07.05.Pj, 07.60.Dq, 94.10.Fa, 94.10.Gb, 94.10.Rk

scholarly journals A Comparison of Einstein A Coefficients for OH Rotational Temperature Measurements Using a Large Astronomical Data Set

Atmosphere ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 569 ◽  
Author(s):  
Murdock Hart
Keyword(s):  
Emission Rate ◽  
Rotational Temperature ◽  
Galactic Evolution ◽  
Atmospheric Measurements ◽  
Data Set ◽  
Astronomical Data ◽  
Broadband Emission ◽  
Volume Emission ◽  
Evolution Experiment ◽  
The Difference

The Einstein A coefficients are considered to be a significant source of uncertainty in the measurement of OH rotational temperatures. Using simultaneous ground and spaced-based observations of OH emission, five sets of Einstein A coefficients were examined for their impact upon rotational temperature calculations. The ground-based observations are taken from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) instrument which is a high resolution, r = λ / Δ λ ≥ 20 , 000 , spectrograph operating in the H-band from approximately 1.5 to 1.7 μ m. APOGEE collected over one-hundred-and-fifty-thousand spectra of the night sky over a period from June 2011 to June 2013. The Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on board the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite has made simultaneous atmospheric measurements with the APOGEE spectrograph. SABER observes the OH volume emission rate (VER) around 1.6 μ m, providing measurements coincident with those of the OH emission in the APOGEE sky spectra. Four of the five sets of Einstein A coefficients tested yielded statistically identical mean rotational temperatures of approximately 195 K for the OH ( 4 − 2 ) transition. The Einstein A coefficients were found to have a significant impact upon the measured OH ( v ′ = 4 ) vibrational populations with some sets of coefficients yielding populations over 50% greater. Simultaneous SABER observations were used to determine which set of Einstein A coefficients best reflected atmospheric temperatures, and four of the five tested coefficients yielded nearly identical results. The difference between OH rotational temperatures and SABER temperatures was on average 1 K.

scholarly journals The OH (3-1) nightglow volume emission rate retrieved from OSIRIS measurements: 2001 to 2015

2021 ◽  
Vol 13 (11) ◽  
pp. 5115-5126
Author(s):  
Anqi Li ◽  
Chris Z. Roth ◽  
Adam E. Bourassa ◽  
Douglas A. Degenstein ◽  
Kristell Pérot ◽  
...  
Keyword(s):  
Emission Rate ◽  
Lower Thermosphere ◽  
Polar Regions ◽  
Night Time ◽  
Data Set ◽  
Infrared Imager ◽  
Data Products ◽  
Long Time ◽  
Volume Emission

Abstract. The OH airglow has been used to investigate the chemistry and dynamics of the mesosphere and the lower thermosphere (MLT) for a long time. The infrared imager (IRI) aboard the Odin satellite has been recording the night-time 1.53 µm OH (3-1) emission for more than 15 years (2001–2015), and we have recently processed the complete data set. The newly derived data products contain the volume emission rate profiles and the Gaussian-approximated layer height, thickness, peak intensity and zenith intensity, and their corresponding error estimates. In this study, we describe the retrieval steps for these data products. We also provide data screening recommendations. The monthly zonal averages depict the well-known annual oscillation and semi-annual oscillation signatures, which demonstrate the fidelity of the data set (https://doi.org/10.5281/zenodo.4746506, Li et al., 2021). The uniqueness of this Odin IRI OH long-term data set makes it valuable for studying various topics, for instance, the sudden stratospheric warming events in the polar regions and solar cycle influences on the MLT.

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