Deactivation of vibrationally excited nitrogen molecules by collision with nitrogen atoms

1987 ◽  
Vol 91 (2) ◽  
pp. 312-314 ◽  
Author(s):  
A. Lagana ◽  
E. Garcia ◽  
L. Ciccarelli
Keyword(s):  
Vibrationally Excited ◽  
Excited Nitrogen

scholarly journals The role of vibrationally excited oxygen and nitrogen in the ionosphere during the undisturbed and geomagnetic storm period of 6-12 April 1990

1998 ◽  
Vol 16 (5) ◽  
pp. 589-601 ◽  
Author(s):  
A. V. Pavlov
Keyword(s):  
Loss Rate ◽  
Boltzmann Distribution ◽  
Rate Coefficients ◽  
Ion Chemistry ◽  
Vibrationally Excited ◽  
Model Calculations ◽  
F Region ◽  
Neutral Temperature ◽  
The Difference ◽  
Excited Nitrogen

Abstract. We present a comparison of the observed behavior of the F-region ionosphere over Millstone Hill during the geomagnetically quiet and storm periods of 6–12 April 1990 with numerical model calculations from the IZMIRAN time-dependent mathematical model of the Earth's ionosphere and plasmasphere. The major enhancement to the IZMIRAN model developed in this study is the use of a new loss rate of O+(4S) ions as a result of new high-temperature flowing afterglow measurements of the rate coefficients K1 and K2 for the reactions of O+(4S) with N2 and O2. The deviations from the Boltzmann distribution for the first five vibrational levels of O2(v) were calculated, and the present study suggests that these deviations are not significant. It was found that the difference between the non-Boltzmann and Boltzmann distribution assumptions of O2(v) and the difference between ion and neutral temperature can lead to an increase of up to about 3 or a decrease of up to about 4 of the calculated NmF2 as a result of a respective increase or a decrease in K2. The IZMIRAN model reproduces major features of the data. We found that the inclusion of vibrationally excited N2(v > 0) and O2(v > 0) in the calculations improves the agreement between the calculated NmF2 and the data on 6, 9, and 10 April. However, both the daytime and nighttime densities are reproduced by the IZMIRAN model without the vibrationally excited nitrogen and oxygen on 8 and 11 April better than the IZMIRAN model with N2(v > 0) and O2(v > 0). This could be due to possible uncertainties in model neutral temperature and densities, EUV fluxes, rate coefficients, and the flow of ionization between the ionosphere and plasmasphere, and possible horizontal divergence of the flux of ionization above the station. Our calculations show that the increase in the O+ + N2 rate factor due to N2(v > 0) produces a 5-36 decrease in the calculated daytime peak density. The increase in the O++ O2 loss rate due to vibrational-ly excited O2 produces 8-46 reductions in NmF2. The effects of vibrationally excited O2 and N2 on Ne and Te are most pronounced during the daytime.Key words. Ion chemistry and composition · Ionosphere – atmosphere interactions · Ionospheric disturbances

Vibrationally excited nitrogen in stable auroral red arcs and its effect on ionospheric recombination

1974 ◽  
Vol 79 (25) ◽  
pp. 3807-3818 ◽  
Author(s):  
George P. Newton ◽  
James C. G. Walker ◽  
P. H. E. Meijer
Keyword(s):  
Vibrationally Excited ◽  
Excited Nitrogen

scholarly journals Mechanisms of the electron density depletion in the SAR arc region

1996 ◽  
Vol 14 (2) ◽  
pp. 211-221 ◽  
Author(s):  
A. V. Pavlov
Keyword(s):  
Electric Field ◽  
Magnetic Storm ◽  
Electron Density ◽  
Drift Velocity ◽  
Recovery Phase ◽  
Electron Densities ◽  
Model Framework ◽  
Vibrationally Excited ◽  
Plasma Drift ◽  
Excited Nitrogen

Abstract. This study compares the measurements of electron density and temperature and the integral airglow intensity at 630 nm in the SAR arc region and slightly south of this (obtained by the Isis 2 spacecraft during the 18 December 1971 magnetic storm), with the model results obtained using the time dependent one-dimensional mathematical model of the Earth\\'s ionosphere and plasmasphere. The explicit expression in the third Enskog approximation for the electron thermal conductivity coefficient in the multicomponent mixture of ionized gases and a simplified calculation method for this coefficient presents an opportunity to calculate more exactly the electron temperature and density and 630 nm emission within SAR arc region are used in the model. Collisions between N2 and hot thermal electrons in the SAR arc region produce vibrationally excited nitrogen molecules. It appears that the loss rate of O+(4S) due to reactions with the vibrationally excited nitrogen is enough to explain electron density depression by a factor of two at F-region heights and the topside ionosphere density variations within the SAR arc if the erosion of plasma within geomagnetic field tubes, during the main phase of the geomagnetic storm and subsequent filling of geomagnetic tubes during the recovery phase, are considered. To explain the disagreement by a factor 1.5 between the observed and modeled SAR arc electron densities an additional plasma drift velocity ~–30 m s–1 in the ion continuity equations is needed during the recovery phase. This additional plasma drift velocity is likely caused by the transition from convecting to corotating flux tubes on the equatorward wall of the trough. The electron densities and temperatures and 630 nm integral intensity at the SAR arc and slightly south of this region as measured for the 18 December 1971 magnetic storm were correctly described by the model without perpendicular electric fields. Within this model framework the effect of the perpendicular electric field ~100 mv m–1 with a duration ~1 h on the SAR arc electron density profiles was found to be large. However, this effect is small if ~1–2 h have passed after the electric field was set equal to zero.

A Simulation Study on the Role of the Vibrationally Excited Nitrogen in the Ionosphere

2004 ◽  
Vol 47 (4) ◽  
pp. 652-659
Author(s):  
Man-Lian ZHANG ◽  
Jian-Kui SHI ◽  
She-Ping SHANG
Keyword(s):  
Simulation Study ◽  
Vibrationally Excited ◽  
Excited Nitrogen

Threshold photoelectron spectroscopy of vibrationally excited nitrogen

2013 ◽  
Vol 46 (4) ◽  
pp. 045002 ◽  
Author(s):  
Fabrizio Innocenti ◽  
Marie Eypper ◽  
Stefano Stranges ◽  
John B West ◽  
George C King ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Vibrationally Excited ◽  
Excited Nitrogen

Vibrational nitrogen concentration in the ionosphere and its dependence on season and solar cycle

1995 ◽  
Vol 13 (11) ◽  
pp. 1164-1171 ◽  
Author(s):  
A. E. Ennis ◽  
G. J. Bailey ◽  
R. J. Moffett
Keyword(s):  
Mathematical Model ◽  
Solar Cycle ◽  
Electron Density ◽  
Geomagnetic Field ◽  
Nitrogen Concentration ◽  
Time Dependent ◽  
Electron Content ◽  
Vibrationally Excited ◽  
F Region ◽  
Excited Nitrogen

Abstract. A fully time-dependent mathematical model, SUPIM, of the Earth's plasmasphere is used in this investigation. The model solves coupled time-dependent equations of continuity, momentum and energy balance for the O+, H+, He+, N+2, O+2, NO+ ions and electrons; in the present study, the geomagnetic field is represented by an axial-centred dipole. Calculation of vibrationally excited nitrogen molecules, which has been incorporated into the model, is presented here. The enhanced model is then used to investigate the behaviour of vibrationally excited nitrogen molecules with F10.7 and solar EUV flux, during summer, winter and equinox conditions. The presence of vibrational nitrogen causes a reduction in the electron content. The diurnal peak in electron content increases linearly up to a certain value of F10.7, and above this value increases at a lesser rate, in agreement with previous observations and modelling work. The value of F10.7 at which this change in gradient occurs is reduced by the presence of vibrational nitrogen. Vibrational nitrogen is most effective at F-region altitudes during summer daytime conditions when a reduction in the electron density is seen. A lesser effect is seen at equinox, and in winter the effect is negligible. The summer reduction in electron density due to vibrational nitrogen therefore reinforces the seasonal anomaly.

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