The O2(b1Σ) dayglow emissions: application to middle and upper atmosphere remote sensing1This article is part of a Special issue that honours the work of Dr. Donald M. Hunten FRSC who passed away in December 2010 after a very illustrious career.

2012 ◽  
Vol 90 (8) ◽  
pp. 769-784 ◽  
Author(s):  
Jeng-Hwa Yee ◽  
R. DeMajistre ◽  
F. Morgan
Keyword(s):  
Remote Sensing ◽  
Cross Sections ◽  
Upper Atmosphere ◽  
Lower Atmosphere ◽  
Spectral Parameters ◽  
Sources And Sinks ◽  
Atmospheric Remote Sensing ◽  
Compositional Structures ◽  
Important Means ◽  
Band Transition

The O2atmospheric band transition is observed in the altitude region between ∼40 and 200 km in the dayglow and between ∼80 and 100 km in the nightglow. Wallace and Hunten (J. Geophys. Res. 73, 4813 (1968)) presented the first detailed analysis of the sources and sinks of this O2airglow emitting state. Because of its extended altitude coverage, bright signal, and spectral and photometric properties, this emission provides an important means to remotely sense the thermal, dynamical, and compositional structures of the upper atmosphere. In this paper we present a photochemical and emission–absorption model that calculates the spectral brightnesses of the four brightest vibrational manifolds of this band system that, for the first time, extends from the mesosphere to the thermosphere. This model incorporates the latest rate constants, cross sections, and spectral parameters relevant to this emission, some of which were not considered in previous remote sensing retrieval applications. The model results are compared with our previous rocket experiments to assess the utility of this emission for upper atmospheric remote sensing and to identify key future measurement challenges. This model, together with improved instrument capabilities, permits us to study the atmosphere from 40 up to 200 km, a region where the strongest coupling between the lower atmosphere and upper atmosphere occurs.

scholarly journals The Radiative Transfer Characteristics of the O2 Infrared Atmospheric Band in Limb-Viewing Geometry

2019 ◽  
Vol 11 (22) ◽  
pp. 2702 ◽  
Author(s):  
Weiwei He ◽  
Kuijun Wu ◽  
Yutao Feng ◽  
Di Fu ◽  
Zhenwei Chen ◽  
...  
Keyword(s):  
Thermal Characteristics ◽  
Spectroscopic Properties ◽  
Upper Atmosphere ◽  
Transfer Model ◽  
Spectral Brightness ◽  
Spectral Parameters ◽  
Line Shapes ◽  
Compositional Structures ◽  
Important Means ◽  
Significant Region

The O2(a1Δg) emission near 1.27 μm provides an important means to remotely sense the thermal characteristics, dynamical features, and compositional structures of the upper atmosphere because of its photochemistry and spectroscopic properties. In this work, an emission–absorption transfer model for limb measurements was developed to calculate the radiation and scattering spectral brightness by means of a line-by-line approach. The nonlocal thermal equilibrium (non-LTE) model was taken into account for accurate calculation of the O2(a1Δg) emission by incorporating the latest rate constants and spectral parameters. The spherical adding and doubling methods were used in the multiple scattering model. Representative emission and absorption line shapes of the O 2 ( a 1 Δ g , υ ′ = 0 ) → O 2 ( X Σ g 3 , υ ″ = 0 ) band and their spectral behavior varying with altitude were examined. The effects of solar zenith angle, surface albedo, and aerosol loading on the line shapes were also studied. This paper emphasizes the advantage of using infrared atmospheric band for remote sensing of the atmosphere from 20 up to 120 km, a significant region where the strongest coupling between the lower and upper atmosphere occurs.

scholarly journals Titan's exosphere and its interaction with Saturn's magnetosphere

2008 ◽  
Vol 367 (1889) ◽  
pp. 743-752 ◽  
Author(s):  
Iannis Dandouras ◽  
Philippe Garnier ◽  
Donald G Mitchell ◽  
Edmond C Roelof ◽  
Pontus C Brandt ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Remote Sensing ◽  
Charge Exchange ◽  
Mass Spectrometer ◽  
Upper Atmosphere ◽  
Neutral Atoms ◽  
Energetic Ions ◽  
Imaging Instrument ◽  
Singly Charged

Titan's nitrogen-rich atmosphere is directly bombarded by energetic ions, due to its lack of a significant intrinsic magnetic field. Singly charged energetic ions from Saturn's magnetosphere undergo charge-exchange collisions with neutral atoms in Titan's upper atmosphere, or exosphere, being transformed into energetic neutral atoms (ENAs). The ion and neutral camera, one of the three sensors that comprise the magnetosphere imaging instrument (MIMI) on the Cassini/Huygens mission to Saturn and Titan, images these ENAs like photons, and measures their fluxes and energies. These remote-sensing measurements, combined with the in situ measurements performed in the upper thermosphere and in the exosphere by the ion and neutral mass spectrometer instrument, provide a powerful diagnostic of Titan's exosphere and its interaction with the Kronian magnetosphere. These observations are analysed and some of the exospheric features they reveal are modelled.

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