Concerning molecular nitrogen in the upper atmosphere

1962 ◽  
Vol 9 (7) ◽  
pp. 437
Keyword(s):  
Molecular Nitrogen ◽  
Upper Atmosphere

scholarly journals The emission of the negative system of nitrogen from the upper atmosphere and the significance of the twilight flash in the theory of the ionosphere

1949 ◽  
Vol 196 (1047) ◽  
pp. 562-591 ◽  
Keyword(s):  
Transition Probability ◽  
Molecular Nitrogen ◽  
Charged Particles ◽  
High Energy ◽  
Upper Atmosphere ◽  
Ionization Mechanisms ◽  
Direct Excitation ◽  
Negative Band ◽  
Resonance Emission ◽  
Excitation Mechanisms

The cause of the emission of the negative band system of nitrogen from the upper atmosphere during twilight is investigated. A study is made of the two possible excitation mechanisms, N 2 ( X 1 Ʃ g + ) + hv →N 2 + ( B 2 Ʃ u + ) + e and N 2 + ( X 2 Ʃ g + ) + hv →N 2 + ( B 2 Ʃ u + ). It is shown that the latter is far more effective than the former, irrespective of the assumptions adopted regarding the solar flux in the unobservable spectral region. From the transition probability associated with it (which is evaluated in the appendix) combined with various intensity estimates, an upper limit is obtained for the number of N 2 + ions normally present in the E and F layers during twilight. It appears that N 2 + ions form but a minute fraction of the total ion content. The significance of this in the theory of the formation of the ionized layers is discussed. The simplest interpretation is that ionization of molecular nitrogen is unimportant; and a reasonable scheme that invokes only the ionization of oxygen atoms and molecules is available. However, by introducing certain arbitrary assumptions a more elaborate interpretation is conceivable so that the view that the E layer arises from the action of high-energy coronal photons, which ionize all atmospheric constituents, cannot be finally rejected. Various aspects of the layers are discussed, and observational and experimental work, which might yield evidence on the ionization mechanisms operative, is suggested. It is pointed out that the remarkable rarity of N 2 + ions proves conclusively that recombination between the charged particles present in the ionosphere cannot be the origin of the nocturnal radiation of the nitrogen band systems. On some occasions the resonance emission at twilight is of unusually high intensity. It is presumed that this is due to incident charged particles increasing the concentration of N 2 + ions. The possible contribution that these charged particles may make to the night-sky light by direct excitation collisions is briefly examined. Sunlit aurorae (which are essentially similar to the twilight flash) are also discussed.

Method of monitoring atomic oxygen and molecular nitrogen composition in the upper atmosphere on XUV images of the Sun

2010 ◽  
Vol 50 (5) ◽  
pp. 679-685 ◽  
Author(s):  
V. G. Mordovskaya ◽  
A. P. Ignat’ev ◽  
S. I. Boldyrev ◽  
S. A. Boldyrev ◽  
G. S. Ivanov-Kholodnyi ◽  
...  
Keyword(s):  
Atomic Oxygen ◽  
Molecular Nitrogen ◽  
Upper Atmosphere ◽  
The Sun

THE SIMULATION OF VIBRATIONAL POPULATIONS OF ELECTRONICALLY EXCITED N2 IN TITAN’S UPPER ATMOSPHERE DURING PRECIPITATIONS OF HIGH-ENERGETIC PARTICLES

2021 ◽  
Vol 44 ◽  
pp. 122-125
Author(s):  
A.S. Kirillov ◽  
◽  
R. Werner ◽  
V. Guineva ◽  
◽  
...  
Keyword(s):  
Molecular Nitrogen ◽  
Excitation Energy Transfer ◽  
Electron Excitation ◽  
Energetic Particles ◽  
Upper Atmosphere ◽  
Radiative Processes ◽  
Calculated Volume ◽  
Ion Production ◽  
Electronically Excited ◽  
Volume Emission

We study the electronic kinetics of singlet molecular nitrogen in Titan’s upper atmosphere during precipitations of high-energetic particles. Both radiative processes and processes of electron excitation energy transfer during inelastic collisions with N2 and CH4 molecules were considered in the calculation of vibrational populations of electronically excited singlet states a'1Σu–, a1Πg, w1Δu of molecular nitrogen in the upper atmosphere of Titan. It is shown that the calculated volume emission intensities of the Lyman-Birge-Hopfield bands correlate with the profiles of the ion production rate in the atmosphere of Titan during the considered cases of electron precipitation for considered interval of the energies 30-1000 eV of magnetospheric electrons. This fact is explained by the negligible contribution of collisional processes to the vibrational populations a1Πg(v'=0-6) in the considered range of heights above 900 km.

Changes in the middle and upper atmosphere parameters during the January 2013 sudden stratospheric warming

2018 ◽  
Vol 4 (4) ◽  
pp. 62-75
Author(s):  
Анна Ясюкевич ◽  
Anna Yasyukevich ◽  
Максим Клименко ◽  
Maksim Klimenko ◽  
Юрий Куликов ◽  
...  
Keyword(s):  
Molecular Nitrogen ◽  
Stratospheric Ozone ◽  
Upper Atmosphere ◽  
Electron Content ◽  
Stratospheric Warming ◽  
Sudden Stratospheric Warming ◽  
Total Electron ◽  
Model Calculations ◽  
Long Time ◽  
Critical Frequency Fof2

We present the results of complex obser-vations of various parameters of the middle and upper atmosphere over Siberia in December 2012 – January 2013, during a major sudden stratospheric warming (SSW) event. We analyze variations in ozone concentration from microwave measurements, in stratosphere and lower mesosphere temperatures from lidar and satellite measurements, in the F2-layer critical frequency (foF2), in the total electron content (TEC), as well as in the ratio of concentrations of atomic oxygen to molecular nitrogen (O/N2) in the thermosphere. To interpret the observed disturbances in the upper atmosphere, the experimental measurements are compared with the results of model calculations obtained with the Global Self-consistent Model of Thermosphere—Ionosphere—Protonosphere (GSM TIP). The response of the upper atmosphere to the SSW event is shown to be a decrease in foF2 and TEC during the evolution of the warming event and a prolonged increase in O/N2, foF2, and TEC after the SSW maximum. For the first time, we observe the relation between the increase in stratospheric ozone, thermospheric O/N2, and ionospheric electron density for a fairly long time (up to 20 days) after the SSW maximum at midlatitudes.

scholarly journals New observations of molecular nitrogen in the Martian upper atmosphere by IUVS on MAVEN

2015 ◽  
Vol 42 (21) ◽  
pp. 9050-9056 ◽  
Author(s):  
M. H. Stevens ◽  
J. S. Evans ◽  
N. M. Schneider ◽  
A. I. F. Stewart ◽  
J. Deighan ◽  
...  
Keyword(s):  
Molecular Nitrogen ◽  
Upper Atmosphere

VUV photochemistry simulation of planetary upper atmosphere using synchrotron radiation

2013 ◽  
Vol 20 (4) ◽  
pp. 587-590 ◽  
Author(s):  
Nathalie Carrasco ◽  
Alexandre Giuliani ◽  
Jean-Jacques Correia ◽  
Guy Cernogora
Keyword(s):  
Synchrotron Radiation ◽  
Preliminary Report ◽  
Vacuum Ultraviolet ◽  
Molecular Nitrogen ◽  
Gas Mixtures ◽  
Upper Atmosphere ◽  
Atmospheric Photochemistry ◽  
Dense Media ◽  
Set Up ◽  
Gas Pressures

The coupling of a gas reactor, named APSIS, with a vacuum-ultraviolet (VUV) beamline at the SOLEIL synchrotron radiation facility, for a photochemistry study of gas mixtures, is reported. The reactor may be irradiated windowless with gas pressures up to hundreds of millibar, and thus allows the effect of energetic photons below 100 nm wavelength to be studied on possibly dense media. This set-up is perfectly suited to atmospheric photochemistry investigations, as illustrated by a preliminary report of a simulation of the upper atmospheric photochemistry of Titan, the largest satellite of Saturn. Titan's atmosphere is mainly composed of molecular nitrogen and methane. Solar VUV irradiation with wavelengths no longer than 100 nm on the top of the atmosphere enables the dissociation and ionization of nitrogen, involving a nitrogen chemistry specific to nitrogen-rich upper atmospheres.

scholarly journals On the wave-length of the green auroral line in the oxygen spectrum

1927 ◽  
Vol 115 (772) ◽  
pp. 515-527 ◽  
Keyword(s):  
Molecular Nitrogen ◽  
Wave Length ◽  
Accurate Determination ◽  
Upper Atmosphere ◽  
Night Sky

It is well known that the spectrum of the aurora is characterised by two outstanding features, the first of which is a set of bands with heads at or near λ = 3914 A, λ = 4278 A, and λ = 4708 A. The second is a strong narrow sharply-defined line close to λ = 5577 A. As to the bands, Lord Rayleigh, Dr. Slipher, Prof. Vegard and others have shown them to be identical with the so-called “negative” bands obtained with molecular nitrogen in the singlyionised state. Nitrogen in this state must, therefore, be one of the main con­stituents of that portion of the upper atmosphere in which auroral displays occur. As to the line λ = 5577 A, it is the strongest constituent of the spectrum of the aurora. Lord Rayleigh, Dr. Slipher, Dr. Babcock and others have shown that it can be obtained as well in the spectrum of the light of the night sky. In 1923 Dr. Babcock made an accurate determination of its wave-length with a Fabry and Perot interferometer and found it to be 5577·350 ± 0·005 I. A.

scholarly journals Electronically excited molecular nitrogen and molecular oxygen in the high-latitude upper atmosphere

2008 ◽  
Vol 26 (5) ◽  
pp. 1159-1169 ◽  
Author(s):  
A. S. Kirillov
Keyword(s):  
High Latitude ◽  
Molecular Nitrogen ◽  
Upper Atmosphere ◽  
Wavelength Shift ◽  
Auroral Ionosphere ◽  
Not Given ◽  
Auroral Electron ◽  
Vibrational Levels ◽  
Electronically Excited ◽  
Vibrational Population

Abstract. Relative vibrational populations of triplet B3Πg, W3Δ,sub>u, B'3Σu− states of N2 and the b1Σg+ state of O2 are calculated for different altitudes of the high-latitude upper atmosphere during auroral electron precipitation. It is shown that collisional processes cause a wavelength shift in the distribution of relative intensities for 1PG Δv=3 sequence of N2. The calculation of relative populations for vibrational levels v=1–5 of the b1Σg+ state in the auroral ionosphere has not given an agreement with experimental results. Preliminary estimation of the contribution of the reaction O2++NO to the production of O2(b1Σg+) on the basis of a quantum-chemical approximation does not allow for an explanation of the observable vibrational population of the b1Σg+ state in the aurora.

scholarly journals Chemical interactions between Saturn’s atmosphere and its rings

Science ◽  
2018 ◽  
Vol 362 (6410) ◽  
pp. eaat2382 ◽  
Author(s):  
J. H. Waite ◽  
R. S. Perryman ◽  
M. E. Perry ◽  
K. E. Miller ◽  
J. Bell ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Volatile Compounds ◽  
Mass Spectrometer ◽  
Chemical Interaction ◽  
Molecular Nitrogen ◽  
Upper Atmosphere ◽  
Atmospheric Structure ◽  
Ring Composition ◽  
Methane Carbon

The Pioneer and Voyager spacecraft made close-up measurements of Saturn’s ionosphere and upper atmosphere in the 1970s and 1980s that suggested a chemical interaction between the rings and atmosphere. Exploring this interaction provides information on ring composition and the influence on Saturn’s atmosphere from infalling material. The Cassini Ion Neutral Mass Spectrometer sampled in situ the region between the D ring and Saturn during the spacecraft’s Grand Finale phase. We used these measurements to characterize the atmospheric structure and material influx from the rings. The atmospheric He/H2 ratio is 10 to 16%. Volatile compounds from the rings (methane; carbon monoxide and/or molecular nitrogen), as well as larger organic-bearing grains, are flowing inward at a rate of 4800 to 45,000 kilograms per second.

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