Processes for meteoric elements in the E-region

Swider, W.

doi:10.1016/0032-0633(69)90014-2

Cited by 75 publications

(29 citation statements)

References 32 publications

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“…The photochemistry of layered metallic ions has ben extensively considered; first with regard to sodium (Blamont and Donahue, 1964;Hunten, 1967) and later for the E region species, silicon, magnesium and iron (Axford and Cunnold, 1966;Donahue, 1966;Whitehead, 1966;Gleeson, 1967;Ferguson and Fehsenfeld, 1968;Narcisi, 1968;Swider, 1969). Although temperate latitude sporadic E events appear to be highly complicated and rather variable in character, a somewhat simplified equilibrium model will be adopted to investigate the implications of the data on the ion-neutral ratio presented in the previous section.…”

Section: Interpretation Of Resultsmentioning

confidence: 99%

“…Attention will be directed primarily toward a determination of the charge transfer + + and.0,. rates between Mg and the ionized species NO Figure 11 represents a schematic of the reactions listed in Table I which constitute the twelve processes thought to be of primary importance (see Ferguson and Fehsenfeld, 1968;Narcisi , 1968 ;Swider, 1969) e Although the layering of metallic species is inherently a time-dependent problem (see Gleeson, 1967), diffusion will not be considered, Rather, an attempt will be made to draw conclusions concerning the rapid exchange reactions, which have characteristic times significantly less than the lifetime of the sporadic E layer. Presumably, the ultimate sink for the Mg atoms is downward diffusion and the ultimate source is meteor ablation.…”

Section: Interpretation Of Resultsmentioning

confidence: 99%

“…sec'l (Swider, 1969) 10-l' cm3 sec-1 (Estimate from 'Bates and Dalgarno, 1962) em3 sec-l (Estimate; Swider, 1969) IO-' cm3 sec'l (Estimate;, Swgder, 1969) + .…”

Section: -7mentioning

confidence: 99%

“…layer generally fitting the description of 1 Results will be interpreted in terms of the general reaction schemes which have recently emerged (for example Swider, 1969;Narcisi, 1968and Ferguson and.…”

Section: Introductionmentioning

confidence: 99%

“…Rate Reference k, = 2.5 x lom1' em6 see', k , = 2.3 x em3 sec-l k, = 1 x loTo cm3 sec-1 (Estimate; Swider, 1969) k*…”

Section: Pheres 1966)mentioning

confidence: 99%

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Rocket investigation of the Mg I and Mg II dayglow

Anderson¹,

Barth²

1971

J. Geophys. Res.

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0The 2800 A dayglow of ionized magnesium in a sporadic E layer was measured by a rocket borne ultraviolet spectrometer. of neutral magnesium was less than 10 Rayleighs while the ionized magnesium emission was measured I to be 360 Rayleighs, the ratio of Mg determined to be greater than 22. A model of the ion chemistry in.the sporadic E layer shows that neutral magnesium is ionized predominately by the + charge transfer reaction with NQ at a rate greater than 7 x 10"' cm3 sec-l or 1.5 x depending on the role MgO, plays in the chemistry.In this model, Mg' is converted back into Mg by radiative recombination. .

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Section: Interpretation Of Resultsmentioning

confidence: 99%

Section: Interpretation Of Resultsmentioning

confidence: 99%

“…sec'l (Swider, 1969) 10-l' cm3 sec-1 (Estimate from 'Bates and Dalgarno, 1962) em3 sec-l (Estimate; Swider, 1969) IO-' cm3 sec'l (Estimate;, Swgder, 1969) + .…”

Section: -7mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…Rate Reference k, = 2.5 x lom1' em6 see', k , = 2.3 x em3 sec-l k, = 1 x loTo cm3 sec-1 (Estimate; Swider, 1969) k*…”

Section: Pheres 1966)mentioning

confidence: 99%

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Rocket investigation of the Mg I and Mg II dayglow

Anderson¹,

Barth²

1971

J. Geophys. Res.

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The effects of deionization processes on meteor radar diffusion coefficients below 90 km

et al. 2014

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The decay times of VHF radar echoes from underdense meteor trails are reduced in the lower portions of the meteor region. This is a result of plasma neutralization initiated by the attachment of positive trail ions to neutral atmospheric molecules. Decreased echo decay times cause meteor radars to produce erroneously high estimates of the ambipolar diffusion coefficient at heights below 90 km, which affects temperature estimation techniques. Comparisons between colocated radars and satellite observations show that meteor radar estimates of diffusion coefficients are not consistent with estimates from the Aura Microwave Limb Sounder satellite instrument and that colocated radars operating at different frequencies estimate different values of the ambipolar diffusion coefficient for simultaneous detections of the same meteors. Loss of free electrons from meteor trails due to attachment to aerosols and chemical processes were numerically simulated and compared with observations to determine the specific mechanism responsible for low‐altitude meteor trail plasma neutralization. It is shown that three‐body attachment of positive metal ions significantly reduces meteor radar echo decay times at low altitudes compared to the case of diffusion only that atmospheric ozone plays little part in the evolution of low‐altitude underdense meteor trails and that the effect of three‐body attachment begins to exceed diffusion in echo decay times at a constant density surface.

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Impacts of meteoric sulfur in the Earth's atmosphere

et al. 2017

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A meteoric sulfur input function and a sulfur ion chemistry scheme have been incorporated into a chemistry‐climate model, in order to study the speciation of sulfur between the stratosphere and the thermosphere (~20–120 km) and the impact of the sulfur input from ablation of cosmic dust. The simulations have been compared to rocket observations of SO+ between 85 and 110 km, MIPAS observations of SO2 between 20 and 45 km, and stratospheric balloon‐borne measurements of H2SO4 vapor and sulfate aerosol. These observations constrain the present‐day global flux of meteoric sulfur to ≤1.0 t S d−1, i.e., 2 orders of magnitude smaller than the flux of S into the stratosphere from OCS photooxidation and explosive volcanic SO2 injection. However, the meteoric sulfur flux is strongly focused into the polar vortices by the meridional circulation, and therefore, the contribution of SO2 of meteoric origin to the polar upper stratosphere during winter is substantial (~ 30% at 50 km for a flux of 1.0 t S d−1). The Antarctic spring sulfate aerosol layer is found to be very sensitive to a moderate increase of the input rate of meteoric sulfur, showing a factor of 2 enhancement in total sulfate aerosol number density at 30 km for an input of 3.0 t S d−1. The input rate estimate of 1.0 t S d−1 suggests an enrichment of sodium relative to sulfur of 2.7 ± 1.5 and is consistent with a total cosmic dust input rate of 44 t d−1.

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Processes for meteoric elements in the E-region

Cited by 75 publications

References 32 publications

Rocket investigation of the Mg I and Mg II dayglow

Rocket investigation of the Mg I and Mg II dayglow

The effects of deionization processes on meteor radar diffusion coefficients below 90 km

Impacts of meteoric sulfur in the Earth's atmosphere

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