Sources and distribution of odd nitrogen in the Venus daytime thermosphere

Gérard, Jean‐Claude; Deneye, E.; Lerho, M.

doi:10.1016/0019-1035(88)90135-2

Cited by 13 publications

(9 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We found that, with a fixed vertical profile of O density derived from VIRTIS O 2 ða 1 DÞ observations, the best fit parameters are / N ¼ 2:1 Â 10 9 cm À2 s À1 and A ¼ 1 Â 10 11 . Gérard et al (1988), Bougher et al (1990) and Brecht et al (2011) found a mean nightside N atom downward flux of 2:1 Â 10 9 ; 1 Â 10 9 and 2 Â 10 9 cm À2 s À1 respectively. In his nightside photochemical model, Krasnopolsky (2010) found a nightside U N equal to 1:2 Â 10 9 .…”

Section: One-dimensional Modelingmentioning

confidence: 98%

The vertical distribution of the Venus NO nightglow: Limb profiles inversion and one-dimensional modeling

Stiepen¹,

Soret²,

Gérard³

et al. 2012

Icarus

View full text Add to dashboard Cite

International audienceUltraviolet (UV) spectra of the δ (190-240 nm) and γ (225-270 nm) bands of the nitric oxide (NO) molecule have been measured on the nightside of the atmosphere of Venus with the Spectroscopy for Investigation of Characteristics of the Atmosphere of Venus (SPICAV) instrument on board Venus Express (VEX). Excited NO molecules on the nightside of the planet are created by radiative recombination of O(3P) and N(4S) atoms. The atoms are produced by photodissociation of CO2 and N2 molecules on the dayside and then transported on the nightside by the global circulation. We analyze all nightside limb profiles obtained since 2006 and provide a statistical study of the nitric oxide airglow layer and its variability. We also apply a spatial deconvolution and an Abel inversion method to the limb profiles to retrieve and quantify the volume emission rate distribution and its dependence on several factors. We also show that about 10% of the limb profiles exhibits a secondary peak located above or below the main airglow peak. Furthermore, a one-dimensional chemical-diffusive model is used to simultaneously model the globally averaged NO and O2(a1Δg) airglow vertical distributions using CO2 and O density profiles rooted in VIRTIS and SPICAV observation

show abstract

Section: One-dimensional Modelingmentioning

confidence: 98%

The vertical distribution of the Venus NO nightglow: Limb profiles inversion and one-dimensional modeling

Stiepen¹,

Soret²,

Gérard³

et al. 2012

Icarus

View full text Add to dashboard Cite

show abstract

“…Presumably, this problem has been resolved with the reduction in the observed emission intensities. Gerard et al (1988) re-examined this problem using a 1-D photochemical-diffusive model that calculated N(4S), N(2D), and NO at selected SZA over the dayside. The daytime ionosphere and odd-nitrogen chemistry were coupled to obtain N(4S) profiles and local time distributions for comparison with PV measurements obtained with the neutral mass spectrometer (Kasprzak et al, 1980;Hedin et al, 1983).…”

Section: No Nightglowmentioning

confidence: 99%

“…The results of the Gerard et al (1988) detailed photochemical model were subsequently used in a 3-D Venus thermospheric general circulation model (VTGCM) to parameterize the sources and sinks of atomic nitrogen in the Venus dayside thermosphere (Bougher et al, 1990a). The VTGCM (see Section 6.2), an adaptation of the terrestrial NCAR TGCM, calculates global distributions of CO2, CO, and O consistent with the 3-D model day-night temperature contrasts and corresponding large-scale winds.…”

Section: No Nightglowmentioning

confidence: 99%

“…The nightward hemispheric flux of N-atoms required to yield 340 to 580 R of dark-disk average airglow is ~ 2.5-3 x 109 cm -2 s-1, which is roughly 30~o of the total dayside N-atoms produced. This is realized for VTGCM cases using standard rate coefficients and branching ratios (Gerard et al, 1988), or slightly reduced NO production through a lower limit N(2D) + CO2 rate coefficient (3 x 10 -13 cm 3 s -~) (Piper etal., 1987). A similar nightglow intensity could be simulated for somewhat weaker NO production coupled with enhanced global mean eddy diffusion (K t _< 2 x 107 cm 2 s 1).…”

Section: No Nightglowmentioning

confidence: 99%

“…Recent measurements of this rate coefficient, however, have yielded values near 1 x 10-12 cm 3 s-1, a factor of 20 less than the Jusinski et al (1988) rate (Piper, 1989;Miller et al, 1988). Further (Venus) progress requires future simultaneous measurements of N(2D), N(4S), and NO in the Venus lower thermosphere (Gerard et al, 1988). NO densities can also be derived from Venus nightside ion chemistry for comparison to VTGCM model values.…”

Section: No Nightglowmentioning

confidence: 99%

See 2 more Smart Citations

Structure, luminosity, and dynamics of the Venus thermosphere

Fox

Bougher

1991

Space Sci Rev

View full text Add to dashboard Cite

We review here observations and models related to the chemical and thermal structures, airglow and auroral emissions and dynamics of the Venus thermosphere, and compare empirical models of the neutral densities based in large part on in situ measurements obtained by the Pioneer Venus spacecraft.Observations of the intensities of emissions are important as a diagnostic tool for understanding the chemical and physical processes taking place in the Venus thermosphere. Measurements, ground-based and from rockets, satellites, and spacecraft, and model predictions of atomic, molecular and ionic emissions, are presented and the most important sources are elucidated. Coronas of hot hydrogen and hot oxygen have been observed to surround the terrestrial planets. We discuss the observations of and production mechanisms for the extended exospheres and models for the escape of lighter species from the atmosphere. Over the last decade and a half, models have attempted to explain the unexpectedly cold temperatures in the Venus thermosphere; recently considerable progress has been made, although some controversies remain. We review the history of these models and discuss the heating and cooling mechanisms that are presently considered to be the most important in determining the thermal structure. Finally, we discuss major aspects of the circulation and dynamics of the thermosphere: the sub-solar to anti-solar circulation, superrotation, and turbulent processes.

show abstract

Nitric oxide nightglow and Martian mesospheric circulation from MAVEN/IUVS observations and LMD‐MGCM predictions

et al. 2017

View full text Add to dashboard Cite

We report results from a study of nitric oxide nightglow over the northern hemisphere of Mars during winter, the southern hemisphere during fall equinox, and equatorial latitudes during summer in the northern hemisphere based on observations of the δ and γ bands between 190 and 270 nm by the Imaging UltraViolet Spectrograph (IUVS) on the Mars Atmosphere and Volatile EvolutioN mission (MAVEN) spacecraft. The emission reveals recombination of N and O atoms dissociated on the dayside of Mars and transported to the nightside. We characterize the brightness (from 0.2 to 30 kR) and altitude (from 40 to 115 km) of the NO nightglow layer, as well as its topside scale height (mean of 11 km). We show the possible impact of atmospheric waves forcing longitudinal variability, associated with an increased brightness by a factor of 3 in the 140–200° longitude region in the northern hemisphere winter and in the −102° to −48° longitude region at summer. Such impact to the NO nightglow at Mars was not seen before. Quantitative comparison with calculations of the LMD‐MGCM (Laboratoire de Météorologie Dynamique‐Mars Global Climate Model) suggests that the model globally reproduces the trends of the NO nightglow emission and its seasonal variation and also indicates large discrepancies (up to a factor 50 fainter in the model) in northern winter at low to middle latitudes. This suggests that the predicted transport is too efficient toward the night winter pole in the thermosphere by ∼20° latitude north.

show abstract

Sources and distribution of odd nitrogen in the Venus daytime thermosphere

Cited by 13 publications

References 40 publications

The vertical distribution of the Venus NO nightglow: Limb profiles inversion and one-dimensional modeling

The vertical distribution of the Venus NO nightglow: Limb profiles inversion and one-dimensional modeling

Structure, luminosity, and dynamics of the Venus thermosphere

Nitric oxide nightglow and Martian mesospheric circulation from MAVEN/IUVS observations and LMD‐MGCM predictions

Contact Info

Product

Resources

About