scholarly journals Contribution of meteor flux in the occurrence of sporadic-E (Es) layers over the Arabian Peninsula

2021 ◽  
Vol 39 (3) ◽  
pp. 471-478
Author(s):  
Muhammad Mubasshir Shaikh ◽  
Govardan Gopakumar ◽  
Aisha Abdulla Al-owais ◽  
Maryam Essa Sharif ◽  
Ilias Fernini
Keyword(s):  
Layered Structure ◽  
Arabian Peninsula ◽  
Lower Ionosphere ◽  
Early Summer ◽  
Upper Atmosphere ◽  
Metallic Ions ◽  
Metal Atoms ◽  
Sporadic E ◽  
Using Data ◽  
Free Metal

Abstract. A sporadic-E (Es) layer is generally associated with a thin-layered structure present in the lower ionosphere, mostly consisting of metallic ions. This metallic ion layer is formed when meteors burn in the upper atmosphere, resulting in the deposition of free metal atoms and ions. Many studies have attributed the presence of the Es layer to the metallic ion layer, specifically when the layer is observed during the nighttime. Using data from a network of meteor monitoring towers and a collocated digital ionosonde radar near the Arabian Peninsula, in this paper, we report our observations of Es layer occurrences together with the meteor count. The trend of monthly averages of Es layer intensity shows a maximum in late spring and early summer months and a minimum in winter months, whereas the meteor counts were highest in winter months and lowest in spring and early summer months. This shows that the presence of the Es layer and the meteor counts have no correlation in time, both diurnally and seasonally. This leads us to conclude that the presence of meteors is not the main cause of the presence of the Es layer over the Arabian Peninsula.

scholarly journals Contribution of Meteor Flux in the Occurrence of Sporadic-E over Arabian Peninsula

2020 ◽  
Author(s):  
Muhammad Mubasshir Shaikh ◽  
Govardan Gopakumar ◽  
Aisha Abdulla Alowais ◽  
Maryam Essa Sharif ◽  
Ilias Fernini
Keyword(s):  
Layered Structure ◽  
Count Data ◽  
Arabian Peninsula ◽  
Lower Ionosphere ◽  
Upper Atmosphere ◽  
Metallic Ions ◽  
Metal Atoms ◽  
Sporadic E ◽  
Using Data ◽  
Free Metal

Abstract. Sporadic-E (Es) is generally associated with a thin-layered structure present in the lower ionosphere mostly consisted of metallic ions. This metallic ion layer is formed when meteors burn in the upper atmosphere resulting in the deposition of free metal atoms and ions. Many studies have attributed to the presence of Es due to metallic ion layer, specifically during the nighttime. Using data from a network of meteor monitoring towers and a collocated digital ionosonde radar near Arabian Peninsula, in this paper, we are reporting our observations of Es together with the meteor count. It has been observed that the presence of Es and the meteor count data have no correlation in time, both diurnally and seasonally, leading us to conclude that presence of meteors is not the main cause for the presence of Es over Arabian Peninsula.

scholarly journals The intensification of metallic layered phenomena above thunderstorms through the modulation of atmospheric tides

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Bingkun Yu ◽  
Xianghui Xue ◽  
Chengling Kuo ◽  
Gaopeng Lu ◽  
Christopher J. Scott ◽  
...  
Keyword(s):  
Lower Ionosphere ◽  
Atmospheric Tides ◽  
Metallic Ions ◽  
Number Density ◽  
Mesopause Region ◽  
Lidar Observation ◽  
Metal Atoms ◽  
Chemical Coupling ◽  
Coupling Processes ◽  
Neutral Metal

AbstractWe present a multi-instrument experiment to study the effects of tropospheric thunderstorms on the mesopause region and the lower ionosphere. Sodium (Na) lidar and ionospheric observations by two digital ionospheric sounders are used to study the variation in the neutral metal atoms and metallic ions above thunderstorms. An enhanced ionospheric sporadic E layer with a downward tidal phase is observed followed by a subsequent intensification of neutral Na number density with an increase of 600 cm−3 in the mesosphere. In addition, the Na neutral chemistry and ion-molecule chemistry are considered in a Na chemistry model to simulate the dynamical and chemical coupling processes in the mesosphere and ionosphere above thunderstorms. The enhanced Na layer in the simulation obtained by using the ionospheric observation as input is in agreement with the Na lidar observation. We find that the intensification of metallic layered phenomena above thunderstorms is associated with the atmospheric tides, as a result of the troposphere-mesosphere-ionosphere coupling.

scholarly journals First simulations of day-to-day variability of mid-latitude sporadic E layer structures

2020 ◽  
Vol 72 (1) ◽  
Author(s):  
Satoshi Andoh ◽  
Akinori Saito ◽  
Hiroyuki Shinagawa ◽  
Mitsumu K. Ejiri
Keyword(s):  
Three Dimensional ◽  
Lower Ionosphere ◽  
Atmospheric Tides ◽  
Ionospheric Model ◽  
Radio Waves ◽  
Metallic Ions ◽  
Long Distance ◽  
Distance Communication ◽  
Sporadic E ◽  
Realistic Information

Abstract We present the first simulations that successfully reproduce the day-to-day variability of the mid-latitude sporadic E ($$E_s$$ E s ) layers. $$E_s$$ E s layers appearing in the lower ionosphere have been extensively investigated to monitor and forecast their effects on long-distance communication by radio waves. Although it is widely accepted that the atmospheric tides are important in generating the $$E_s$$ E s layers, no simulations to date have reproduced the $$E_s$$ E s layers observed on a certain day. This is due to the lack of the combination of realistic information on the atmospheric tides in the lower ionosphere and a three-dimensional numerical ionospheric model that can simulate the precise transport of metallic ions. We developed a numerical ionospheric model coupled with the neutral winds from the GAIA (Ground-to-topside model of Atmosphere and Ionosphere for Aeronomy). The fundamental structures and the day-to-day variations of the $$E_s$$ E s layers observed by a $$\hbox {Ca}^+$$ Ca + lidar are well-reproduced in the simulations.

scholarly journals The intensification of metallic layered phenomena above thunderstorms through the modulation of atmospheric tides

2018 ◽  
Author(s):  
Bingkun Yu ◽  
Xianghui Xue ◽  
Chengling Kuo ◽  
Gaopeng Lu ◽  
Xiankang Dou ◽  
...  
Keyword(s):  
Lower Ionosphere ◽  
Atmospheric Tides ◽  
Metallic Ions ◽  
Mesopause Region ◽  
Lidar Observation ◽  
Chemical Coupling ◽  
Sporadic E Layer ◽  
Sporadic E ◽  
Coupling Processes ◽  
Neutral Metal

Abstract. We present a multi-instrument experiment to study the effects of tropospheric thunderstorms on the mesopause region and the lower ionosphere. The sodium (Na) lidar observation and the ionospheric observation by two digital ionospheric sounders are used to study the variation of the neutral metal atoms and metallic ions above thunderstorms. The enhanced ionospheric sporadic E layer with a downward tidal phase is observed followed by a subsequent intensification of neutral Na density with an increase of 600 cm−3 in the mesosphere. In addition, the Na neutral chemistry and ion-molecule chemistry reactions are considered in the Na chemistry model to simulate the dynamical and chemical coupling processes in the mesosphere and ionosphere above thunderstorms. The enhanced Na layer in the simulation using the ionospheric observation as input is in agreement with the Na lidar observation. We find that the intensification of metallic layered phenomena above thunderstorms is associated with the atmospheric tides, as a result of the troposphere-mesosphere-ionosphere coupling.

Effects of reactive gas addition on ionization of metal atoms in droplet-free metal ion sources

2007 ◽  
Vol 201 (15) ◽  
pp. 6655-6659 ◽  
Author(s):  
Keiji Nakamura ◽  
Akira Wakayama ◽  
Ken Yukimura
Keyword(s):  
Metal Ion ◽  
Ion Sources ◽  
Metal Atoms ◽  
Free Metal ◽  
Free Metal Ion ◽  
Reactive Gas

scholarly journals Enhanced sporadic <i>E</i> occurrence rates during the Geminid meteor showers 2006–2010

2013 ◽  
Vol 11 ◽  
pp. 313-318 ◽  
Author(s):  
C. Jacobi ◽  
C. Arras ◽  
J. Wickert
Keyword(s):  
Northern Hemisphere ◽  
Strong Correlation ◽  
Wind Shear ◽  
Radio Occultation ◽  
Semidiurnal Tide ◽  
Metallic Ions ◽  
Meteor Radar ◽  
Meteor Showers ◽  
Short Delay ◽  
Sporadic E

Abstract. Northern Hemisphere midlatitude sporadic E (Es) layer occurrence rates derived from FORMOSAT-3/COSMIC GPS radio occultation (RO) measurements during the Geminid meteor showers 2006–2010 are compared with meteor rates obtained with the Collm (51.3° N, 13.0° E) VHF meteor radar. In most years, Es rates increase after the shower, with a short delay of few days. This indicates a possible link between meteor influx and the production of metallic ions that may form Es. There is an indication that the increase propagates downward, probably partly caused by tidal wind shear. However, the correlation between Es rates and meteor flux varies from year to year. A strong correlation is found especially in 2009, while in 2010 Es rates even decrease during the shower. This indicates that additional processes significantly influence Es occurrence also during meteor showers. A possible effect of the semidiurnal tide is found. During years with weaker tidal wind shear, the correlation between Es and meteor rates is even weaker.

scholarly journals Type-1 echoes from the mid-latitude E-Region ionosphere

1997 ◽  
Vol 15 (7) ◽  
pp. 908-917 ◽  
Author(s):  
C. Haldoupis ◽  
D. T. Farley ◽  
K. Schlegel
Keyword(s):  
Doppler Radar ◽  
Spectral Component ◽  
Equatorial Electrojet ◽  
Metallic Ions ◽  
Sporadic E Layers ◽  
E Region ◽  
Sporadic E ◽  
The Right

Abstract. This paper presents more data on the properties of type-1 irregularities in the nighttime mid-latitude E-region ionosphere. The measurements were made with a 50-MHz Doppler radar system operating in Crete, Greece. The type-1 echoes last from several seconds to a few minutes and are characterized by narrow Doppler spectra with peaks corresponding to wave phase velocities of 250–350 m/s. The average velocity of 285 m/s is about 20% lower than nominal E-region ion-acoustic speeds, probably because of the presence of heavy metallic ions in the sporadic-E-layers that appear to be associated with the mid-latitude plasma instabilities. Sometimes the type-1 echoes are combined with a broad spectrum of type-2 echoes; at other times they dominate the spectrum or may appear in the absence of any type-2 spectral component. We believe these echoes are due to the modified two-stream plasma instability driven by a polarization electric field that must be larger than 10 mV/m. This field is similar in nature to the equatorial electrojet polarization field and can arise when patchy nighttime sporadic-E-layers have the right geometry.

scholarly journals Interhemispheric transport of metallic ions within ionospheric sporadic E layers by the lower thermospheric meridional circulation

2020 ◽  
Author(s):  
Bingkun Yu ◽  
Xianghui Xue ◽  
Christopher J. Scott ◽  
Jianfei Wu ◽  
Xinan Yue ◽  
...  
Keyword(s):  
Large Scale ◽  
Climate Model ◽  
Meridional Circulation ◽  
Strong Support ◽  
Metallic Ions ◽  
Meridional Transport ◽  
Summer Circulation ◽  
Sporadic E Layers ◽  
Sporadic E ◽  
Interhemispheric Transport

Abstract. Long-lived metallic ions in the Earth's atmosphere/ionosphere have been investigated for many decades. Although the seasonal variation in ionospheric sporadic E layers was first observed in the 1960s, the mechanism driving the variation remains a long-standing mystery. Here we report a study of ionospheric irregularities using scintillation data from COSMIC satellites and identify a large-scale horizontal transport of long-lived metallic ions, combined with the simulations of the Whole Atmosphere Community Climate Model with the chemistry of metals and ground-based observations from two meridional chains of stations from 1975–2016. We find that the lower thermospheric meridional circulation influences the meridional transport and seasonal variations of metallic ions within sporadic E layers. The winter-to-summer, meridional velocity of ions is estimated to vary between −1.08 and 7.45 m/s at altitudes of 107–118 km between 10°–60° N latitude. Our results not only provide strong support for the lower thermospheric meridional circulation predicted by a whole atmosphere chemistry-climate model, but also emphasise the influences of this winter-to-summer circulation on the large-scale interhemispheric transport of composition in the thermosphere/ionosphere.

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