Global variation of meteor trail plasma turbulence

Dyrud, L. P.; Urbina, Julio; Fentzke, J. T.; Hibbit, E.; Hinrichs, Johannes

doi:10.5194/angeo-29-2277-2011

Cited by 13 publications

(23 citation statements)

References 38 publications

(51 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Kim et al (2010) have argued that chemistry in summer, through water cluster ions, could have a similar effect. Another weak/strong effect was proposed by Dyrud et al (2011), who modelled plasma turbulence created by the meteor itself and found a day (smaller) to night (larger) difference in generated turbulence. Here the strong trails decay faster than ambipolar diffusion would predict.…”

Section: Introductionmentioning

confidence: 99%

Eureka, 80° N, SKiYMET meteor radar temperatures compared with Aura MLS values

et al. 2013

View full text Add to dashboard Cite

The meteor trail echo decay rates are analysed on-site to provide daily temperatures near 90 km. In order to get temperatures from trail decay times, either knowledge of the pressure or the background temperature height gradient near 90 km is required (Hocking, 1999). Hocking et al. (2004) have developed an empirical 90 km temperature gradient model depending only on latitude and time of year, which is used in the SKiYMET on-site meteor temperature analysis.

Here we look at the sensitivity of the resulting temperature to the assumed gradient and compare it and the temperatures with daily AuraMLS averages near Eureka. Generally there is good agreement between radar and satellite for winter temperatures and their short-term variations. However there is a major difference in mid-summer both in the temperatures and the gradients. Increased turbulence in summer, which may overwhelm the ambipolar diffusion even at 90 km, is likely a major factor.

These differences are investigated by generating ambipolar-controlled decay times from satellite pressure and temperature data at a range of heights and comparing with radar measurements. Our study suggests it may be possible to use these data to estimate eddy diffusion coefficients at heights below 90 km. Finally the simple temperature analysis (using satellite pressures), and a standard meteor wind analysis are used to compare mean diurnal variations of temperature (T) with those of zonal wind (U) and meridional wind (V) in composite multi-year monthly intervals

show abstract

Section: Introductionmentioning

confidence: 99%

Eureka, 80° N, SKiYMET meteor radar temperatures compared with Aura MLS values

et al. 2013

View full text Add to dashboard Cite

show abstract

“…On the other hand, massive meteor trails have been observed by various radars (Briczinski et al, 2009;Ceplecha et al, 1998;Dyrud et al, 2011;Janches et al, 2001;Sugar et al, 2010;Zeng and Yi, 2011;Zhou and Perillat, 1998). Furthermore, there is some experimental evidence for a correlation between Na s and Es layer occurrence and meteor rates (Batista et al, 1989;Dou et al, 2010;Hansen and von Zahn, 1990;Hoeffner and Friedman, 2005;Höffner and Friedman, 2004), combined with the similar quasi-periodic oscillation and spatially localized scattering regions in Na s , Es and meteor trails, so that a possible role of meteor deposition in the formation of Na s layers should not be discarded.…”

Section: The Quasi-periodic Oscillation Phenomenon In Na S Layersmentioning

confidence: 98%

“…In this respect it should be noted that the metallic atoms detected were potassium and calcium, and these two metallic atoms have far lower abundances than those of sodium and iron in the meteor ablation region. Alternatively, the duration of these trails might be too short, on the order of milliseconds, to be detected by a lidar with a relative low repetition rate (Briczinski et al, 2009;Dyrud et al, 2011;Pfrommer et al, 2009). Only those metallic atomic trails strong enough and lasting long enough relative to the lidar would be discerned easily.…”

Section: The Quasi-periodic Oscillation Phenomenon In Na S Layersmentioning

confidence: 99%

“…Every day, billions of microgram-sized extraterrestrial particles from sporadic meteor activity enter and ablate in the upper layers of the earth's atmosphere, which gives rise to the upper atmospheric ion and metallic layers observed by incoherent scatter radars (ISR) and lidars, respectively (Ceplecha et al, 1998;Dyrud et al, 2011;Janches et al, 2006). The Mesosphere and Lower Thermosphere (MLT) region shows various types of fine structure, like the polar mesospheric or noctilucent clouds (PMC/NLC), which are believed to consist of ice crystals with the nuclei of extraterrestrial meteoric dust (Clemesha, 2004;Janches et al, 2004), the sporadic-Eion (Es) layers believed to consist of metallic ions of meteoric origin, concentrated into a thin layer by the effect of wind-shear in the presence of the earth's magnetic field (Mathews, 1998;Whitehead, 1989), and the less well understood thin layers of meteoric metals known as sporadic neutral (Ns) layers.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Comparison of sporadic sodium layer characteristics observed at different time resolutions

et al. 2013

View full text Add to dashboard Cite

Abstract. Sporadic sodium (Na s ) layers, occurring in roughly the same height range as ionospheric sporadic-E layers, were first detected by lidar some 30 yr ago. Na s layers have a typical thickness of a few hundred meters to a few km, with peak atom concentrations several times that of the background layer. Despite a great deal of excellent work over the past decades, the source of Na s layers is still not altogether clear, partly as a result of our incomplete knowledge of Na s layer characteristics. In this paper we concentrate on some typical case studies chosen from the ∼ 127 h of sporadic sodium layer observations made at a time resolution of 1.5 s at Yanqing (115.97 • E, 40.47 • N), Beijing, China. This is a much better time resolution than what has been employed in most earlier measurements. The results show that the Na s layer peak heights are dispersed at slightly different although adjacent heights. When averaged over several minutes, as has been the case with most earlier measurements, the height scatter results in an apparent layer thickness of a few km. We conclude, therefore, that these dispersed peaks at different but adjacent heights constitute the 5 min Na s layer. Similar to the observations of sporadic-E-ion (Es) layers and meteor rate, we observe quasi-periodic fluctuations on a timescale on the order of several minutes in the peak height and the peak density of sporadic layers, which is a universal feature but concealed by the lower temporal resolution previously adopted. Spatially localized multiple scatterers and multiple thin layers with similar apparent movement in Na s layers are also found. We discuss the possible formation mechanism by the direct deposition of large swarms of micrometeoroids and demonstrate a typical example of meteor trails evolving into a Na s layer, which suggests that this mechanism might indeed occur.

show abstract

“…The model trail grows to the size of 10 m, when its surface brightness becomes too low for further observational consideration. The trail duration can vary significantly and it depends on many factors: the meteor velocity, the trail density, the ionosphere electron density, the presence of background winds and electric fields resulting from the ionospheric electrojets (Dyrud et al 2011), etc. The basic assumption is that trails diffuse into disappearance exponentially in time as e −t/τ , with τ less than a second or just a few seconds (Hocking et al 2016), although sometimes they can remain glowing for minutes (Dyrud, Kudeki and Oppenheim 2007).…”

Section: Defocussing Of Meteor Trailsmentioning

confidence: 99%

Linear feature detection algorithm for astronomical surveys – II. Defocusing effects on meteor tracks

Bektesevic¹,

Vinković²,

Rasmussen

et al. 2017

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

Given the current limited knowledge of meteor plasma micro-physics and its interaction with the surrounding atmosphere and ionosphere, meteors are a highly interesting observational target for high-resolution wide-field astronomical surveys. Such surveys are capable of resolving the physical size of meteor plasma heads, but they produce large volumes of images that need to be automatically inspected for possible existence of long linear features produced by meteors. Here we show how big aperture sky survey telescopes detect meteors as defocused tracks with a central brightness depression. We derive an analytic expression for a defocused point source meteor track and use it to calculate brightness profiles of meteors modeled as uniform brightness disks. We apply our modeling to meteor images as seen by the SDSS and LSST telescopes. The expression is validated by Monte Carlo ray-tracing simulations of photons traveling through the atmosphere and the LSST telescope optics. We show that estimates of the meteor distance and size can be extracted from the measured FWHM and the strength of the central dip in the observed brightness profile. However, this extraction becomes difficult when the defocused meteor track is distorted by the atmospheric seeing or contaminated by a long lasting glowing meteor trail. The FWHM of satellites tracks is distinctly narrower than meteor values, which enables removal of a possible confusion between satellites and meteors.

show abstract

Global variation of meteor trail plasma turbulence

Cited by 13 publications

References 38 publications

Eureka, 80° N, SKiYMET meteor radar temperatures compared with Aura MLS values

Eureka, 80° N, SKiYMET meteor radar temperatures compared with Aura MLS values

Comparison of sporadic sodium layer characteristics observed at different time resolutions

Linear feature detection algorithm for astronomical surveys – II. Defocusing effects on meteor tracks

Contact Info

Product

Resources

About