The Mg II equatorial airglow altitude distribution

Gérard, Jean‐Claude; Monfils, A.

doi:10.1029/ja083ia09p04389

Cited by 25 publications

(16 citation statements)

References 7 publications

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“…Subsequent papers reinforced the fountain eect interpretation (Hanson et al, 1972) and revealed a strong correlation between equatorial spread-F (ESF) and the presence of Fe + . Other analyses of data from OGO-4 and OGO-6 (Taylor, 1973), ESRO TD-1A (Gerard, 1976;Gerard and Mon®ls, 1978), and AE-C and AE-E (Grebowsky and Brinton, 1978;Grebowsky and Reese, 1989) revealed similar ion densities, consistent with the idea of upward vertical transport near the magnetic equator. Recent observations by the GLO instrument on the Space Shuttle have provided the ®rst simultaneous observations of Mg and Mg + in the thermosphere (Gardner et al, 1995).…”

Section: Brief History Of Observational Workmentioning

confidence: 51%

Global transport and localized layering of metallic ions in the upper atmospherer

Carter

Forbes

1999

Ann. Geophys.

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Abstract. A numerical model has been developed which is capable of simulating all phases of the life cycle of metallic ions, and results are described and interpreted herein for the typical case of Fe + ions. This cycle begins with the initial deposition of metallics through meteor ablation and sputtering, followed by conversion of neutral Fe atoms to ions through photoionization and charge exchange with ambient ions. Global transport arising from daytime electric ®elds and poleward/ downward diusion along geomagnetic ®eld lines, localized transport and layer formation through descending convergent nulls in the thermospheric wind ®eld, and ®nally annihilation by chemical neutralization and compound formation are treated. The model thus sheds new light on the interdependencies of the physical and chemical processes aecting atmospheric metallics. Model output analysis con®rms the dominant role of both global and local transport to the ion's life cycle, showing that upward forcing from the equatorial electric ®eld is critical to global movement, and that diurnal and semidiurnal tidal winds are responsible for the formation of dense ion layers in the 90±250 km height region. It is demonstrated that the assumed combination of sources, chemical sinks, and transport mechanisms actually produces F-region densities and E-region layer densities similar to those observed. The model also shows that zonal and meridional winds and electric ®elds each play distinct roles in local transport, whereas the ion distribution is relatively insensitive to reasonable variations in meteoric deposition and chemical reaction rates.

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Section: Brief History Of Observational Workmentioning

confidence: 51%

Global transport and localized layering of metallic ions in the upper atmospherer

Carter

Forbes

1999

Ann. Geophys.

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“…Optical emissions from neutral and ionized magnesium were first observed in 1970 by a sounding rocket and later by several satellites and the space shuttle [ Anderson and Barth , 1971[link]; Gérard , 1976; Gérard and Monfils , 1974[link], 1978; Gérard et al , 1979[link]; Fesen and Hays , 1982[link]; Mende et al , 1985; Gardener et al , 1995[link]; Joiner and Aikin , 1996[link]]. The Mg + 2800 Å doublet and the Fe + 2600 Å lines were also observed by the Hubble Space Telescope during the impacts of Comet Shoemaker‐Levy 9 with Jupiter [ Noll et al , 1995[link]].…”

Section: Introductionmentioning

confidence: 99%

Middle ultraviolet emission from ionized iron

Dymond

Wolfram

Budzien

et al. 2003

Geophysical Research Letters

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We present middle ultraviolet spectra between 2300 and 2700 Å showing emissions due to singly ionized iron and magnesium. The spectra were observed by the Ionospheric Spectroscopy and Atmospheric Chemistry (ISAAC) instrument on the United States Air Force's Advanced Research and Global Observing Satellite (ARGOS). The emission from ionized magnesium has been previously observed and studied; however, the ionized iron lines near 2400 and 2600 Å are newly identified in the Earth's middle ultraviolet dayglow spectrum. Newly calculated fluorescence efficiencies for excitation of the optical emissions are also presented.

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“…Fesen et al (1983) showed that additionally neutral meridional winds have to be taken into account in order to explain vertical transport also at higher latitudes up to 30 • and this was experimentally shown, e.g. in Fesen and Hays (1982a, b) and Gérard and Monfils (1978).…”

Section: Langowski Et Al: Global Investigation Of the Mg Atom Andmentioning

confidence: 99%

“…No Mg signal above the instrumental noise was observed in these spectra. The region above the peak altitude from 150 km up to the F-layer and above was investigated by Gérard and Monfils (1978), Fesen and Hays (1982a), Mende et al (1985), Gardner et al (1995) and Gardner et al (1999) and typically shows less than 100 cm −3 Mg + ions at 150 km altitude. This is in good agreement with the profiles described in Sect.…”

Section: Comparison To Other Measurementsmentioning

confidence: 99%

Global investigation of the Mg atom and ion layers using SCIAMACHY/Envisat observations between 70 and 150 km altitude and WACCM-Mg model results

et al. 2015

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Abstract. Mg and Mg + concentration fields in the upper mesosphere/lower thermosphere (UMLT) region are retrieved from SCIAMACHY/Envisat limb measurements of Mg and Mg + dayglow emissions using a 2-D tomographic retrieval approach. The time series of monthly mean Mg and Mg + number density and vertical column density in different latitudinal regions are presented. Data from the limb mesosphere-thermosphere mode of SCIAMACHY/Envisat are used, which cover the 50 to 150 km altitude region with a vertical sampling of ≈ 3.3 km and latitudes up to 82• . The high latitudes are not observed in the winter months, because there is no dayglow emission during polar night. The measurements were performed every 14 days from mid-2008 until April 2012. Mg profiles show a peak at around 90 km altitude with a density between 750 cm −3 and 1500 cm −3 . Mg does not show strong seasonal variation at latitudes below 40 • . For higher latitudes the density is lower and only in the Northern Hemisphere a seasonal cycle with a summer minimum is observed. The Mg + peak occurs 5-15 km above the neutral Mg peak altitude. These ions have a significant seasonal cycle with a summer maximum in both hemispheres at mid and high latitudes. The strongest seasonal variations of Mg + are observed at latitudes between 20 and 40• and the density at the peak altitude ranges from 500 cm −3 to 4000 cm −3 . The peak altitude of the ions shows a latitudinal dependence with a maximum at mid latitudes that is up to 10 km higher than the peak altitude at the equator.The SCIAMACHY measurements are compared to other measurements and WACCM model results. The WACCM results show a significant seasonal variability for Mg with a summer minimum, which is more clearly pronounced than for SCIAMACHY, and globally a higher peak density than the SCIAMACHY results. Although the peak density of both is not in agreement, the vertical column density agrees well, because SCIAMACHY and WACCM profiles have different widths. The agreement between SCIAMACHY and WACCM results is much better for Mg + with both showing the same seasonality and similar peak density. However, there are also minor differences, e.g. WACCM showing a nearly constant altitude of the Mg + layer's peak density for all latitudes and seasons.

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The Mg II equatorial airglow altitude distribution

Cited by 25 publications

References 7 publications

Global transport and localized layering of metallic ions in the upper atmospherer

Global transport and localized layering of metallic ions in the upper atmospherer

Middle ultraviolet emission from ionized iron

Global investigation of the Mg atom and ion layers using SCIAMACHY/Envisat observations between 70 and 150 km altitude and WACCM-Mg model results

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