Sporadic Enhancement of the Mesospheric Sodium during the Perseids .GAMMA. Meteor Shower.

Uchiumi, Masaharu; Nagasawa, Chikao; Hirono, Motokazu; Fujiwara, Motowo; Maeda, Mitsuo

doi:10.5636/jgg.45.393

Cited by 6 publications

(4 citation statements)

References 29 publications

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“…Throughout the literature, many discussions have focused either on these permanent metal layers or on infrequent events, such as sporadic layers or single meteor trails, and their influences on the average metal layers (Hacke et al, 1972;Me´gie and Blamont, 1977;Uchiumi et al, 1993;Gerding et al, 1999; Chu et al, 2000;Raizada et al, 2004). Even though it has been known for a long time that free metal atoms are occasionally observable for short periods of time at altitudes above 110 km, the presence of a permanent metal layer at those altitudes has not received attention.…”

Section: Introductionmentioning

confidence: 97%

The mesospheric metal layer topside: Examples of simultaneous metal observations

Höffner

Friedman

2005

Journal of Atmospheric and Solar-Terrestrial Physics

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Section: Introductionmentioning

confidence: 97%

The mesospheric metal layer topside: Examples of simultaneous metal observations

Höffner

Friedman

2005

Journal of Atmospheric and Solar-Terrestrial Physics

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“…Proving that meteor showers can change the average properties of metal layers has turned out to be even more difficult. Some authors have found a correlation (Hake et al, 1972;Megie and Blamont, 1977;Uchiumi et al, 1993;Gerding et al, 1999;Höffner et al, 1999) and others not (Chu et al, 2000;Höffner et al, 2000). Often such experiments were performed only one time and during the meteor shower itself, and thus lack information about the always present natural variability.…”

Section: Introductionmentioning

confidence: 99%

Metal layers at high altitudes: A possible connection to meteoroids

Höffner¹,

Friedman²

2004

Preprint

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Abstract. In the past, many studies have been carried out to demonstrate the influence of meteoroids on the atmospheric metal layer, observed roughly in the altitude range 80–105 km. Even with the capability of present day resonance lidars to measure metal densities within single meteor trails, it has been difficult to prove any influence of meteors on the average metal layer. In contrast to approaches taken earlier, we discuss here the seasonal characteristics of potassium, calcium, calcium ion, iron and sodium above 110 km altitude where the average nocturnal densities are so low that the existence of a baseline level of metal atoms and ions is often overlooked. By comparing simultaneous and common-volume observations of different metal layers at one location, we demonstrate that despite their different seasonal characteristics at lower altitudes remarkably similar seasonal characteristics are observed at higher altitudes. In addition, for potassium at different latitudes a qualitative agreement is also found. A comparison of metal densities at 113 km altitude with known meteor showers indicates a strong influence of shower meteoroids on the topside of the metal layers. Simultaneous observations of K along with Ca, Fe and/or Na permits the calculation of abundance ratios. We find that these ratios at 113 km altitude are quite similar to values measured in single meteor trails by ground based lidars. Given these evidences, we contend that there is a direct influence of ablating meteoroids on the topside of the mesospheric metal layer. Furthermore, the increase in densities throughout summer with similar abundance ratios as observed during meteor showers is a strong evidence for the influence of sporadic meteoroids on the high metal layers.

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“…There have been some studies investigating a possible correlation between neutral metal densities and the influx of meteor material during meteor showers. Some of the authors report an influence (Uchiumi et al, 1993;Gerding et al, 1999;Höffner et al, 1999), but mostly for a very short time. From four hours of lidar measurements, a fourfold increase in Na density was reported by Hake et al (1972).…”

Section: Published By Copernicus Publications On Behalf Of the Europementioning

confidence: 99%

“…Clemesha et al (1999) concluded the ion-recombination mechanism to be the most likely cause for sporadic Na layers. Other studies of sporadic Na layers by lidar at high latitudes have suggested mechanisms for their generation unrelated to direct meteor input: von Zahn et al (1987), von Zahn and Hansen (1988), Hansen and von Zahn (1990), Heinselman et al (1998), Nesse et al (2008), Heinrich et al (2008). We will first describe our instruments, briefly investigate the atmospheric conditions during the lidar measurements and then concentrate on the Na layer properties and their relation to meteor flux rates and meteoric smoke particles.…”

Section: Published By Copernicus Publications On Behalf Of the Europementioning

confidence: 99%

Development of the mesospheric Na layer at 69° N during the Geminids meteor shower 2010

et al. 2013

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Abstract. The ECOMA sounding rocket campaign in 2010 was performed to investigate the charge state and number density of meteoric smoke particles during the Geminids meteor shower in December 2010. The ALOMAR Na lidar contributed to the campaign with measurements of sodium number density, temperature and line-of-sight wind between 80 and 110 km altitude over Andøya in northern Norway. This paper investigates a possible connection between the Geminids meteor shower and the mesospheric sodium layer. We compare with data from a meteor radar and from a rocketborne in situ particle instrument on three days. Our main result is that the sodium column density is smaller during the Geminids meteor shower than the winter average at the same latitude. Moreover, during two of the three years considered, the sodium column density decreased steadily during these three weeks of the year. Both the observed decrease of Na column density by 30 % and of meteoric smoke particle column density correlate well with a corresponding decrease of sporadic meteor echoes. We found no correlation between Geminids meteor flux rates and sodium column density, nor between sporadic meteors and Na column density (R = 0.25). In general, we found the Na column density to be at very low values for winter, between 1.8 and 2.6 × 10 13 m −2 . We detected two meteor trails containing sodium, on 13 December 2010 at 87.1 km and on 19 December 2010 at 84 km. From these meteor trails, we estimate a global meteoric Na flux of 121 kg d −1 and a global total meteoric influx of 20.2 t d −1 .

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Sporadic Enhancement of the Mesospheric Sodium during the Perseids .GAMMA. Meteor Shower.

Cited by 6 publications

References 29 publications

The mesospheric metal layer topside: Examples of simultaneous metal observations

The mesospheric metal layer topside: Examples of simultaneous metal observations

Metal layers at high altitudes: A possible connection to meteoroids

Development of the mesospheric Na layer at 69° N during the Geminids meteor shower 2010

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