Temporal Evolution of Three‐Dimensional Structures of Metal Ion Layer Around Japan Simulated by a Midlatitude Ionospheric Model

Andoh, Satoshi; Saito, Akinori; Shinagawa, Hiroyuki

doi:10.1029/2021ja029267

Cited by 15 publications

(22 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The wind‐shear effect on the Es occurrence rate and average S4 index is more pronounced above 100 km than below, consistent with the numerical work by Andoh et al. (2021). Below 100 km, frequent ion‐neutral collisions suppress the formation of an Es layer by the wind shear mechanism…”

Section: Discussionsupporting

confidence: 90%

“…The vertical shear of the meridional wind has little impact on Es for the height range of 90–120 km The wind‐shear effect on the Es occurrence rate and average S4 index is more pronounced above 100 km than below, consistent with the numerical work by Andoh et al. (2021). Below 100 km, frequent ion‐neutral collisions suppress the formation of an Es layer by the wind shear mechanism Es can be observed even in the absence of vertical wind shear.…”

Section: Discussionsupporting

confidence: 87%

“…Such a significant difference is not found in the results obtained for different periods or latitudes. The reduced wind-shear influence at the lower altitudes can be explained as the consequence of frequent ion-neutral collisions in the lower E region, which suppress the Es formation by the wind shear mechanism, as numerically demonstrated by Andoh et al (2021).…”

Section: Resultsmentioning

confidence: 73%

See 2 more Smart Citations

Examining the Wind Shear Theory of Sporadic E With ICON/MIGHTI Winds and COSMIC‐2 Radio Occultation Data

Yamazaki

Arras

Andoh

et al. 2021

Geophysical Research Letters

Self Cite

View full text Add to dashboard Cite

Metallic ion layers are commonly observed in the ionosphere. In particular, those which occur at E-region heights show high plasma concentrations, and they can cause anomalous high frequency (HF) radio propagation, known as Es. The characterization of the phenomenon and the formation mechanism for Es layers have been a subject of study for many decades (see, e.g., reviews by Haldoupis, 2011;Mathews, 1998;Whitehead, 1989). Observations of Es have been made using various instruments and techniques, including ionosondes (e.g., Taguchi, 1961), sounding rockets (e.g., Smith, 1966), incoherent scatter radars (e.g., Miller & Smith, 1978), lidars (e.g., Gardner et al., 1993, and radio occultation measurements (e.g., Hocke et al., 2001). It is now well established that Es layers occur most frequently at mid latitudes (20°-50° latitude) in the summer hemisphere at altitudes of 90-120 km.The formation of an Es layer requires the convergence of ion flux. The wind shear theory (Axford, 1963;Whitehead, 1961) suggests that the required ion flux convergence can be realized by the vertical shear of horizontal neutral winds. The following simple expression can be obtained for the vertical component of the ion velocity, under the assumption of balance between the Lorentz force due to ion motions across the ambient geomagnetic field and the frictional force due to ion-neutral collisions (e.g., Haldoupis, 2011):

show abstract

Section: Discussionsupporting

confidence: 90%

Section: Discussionsupporting

confidence: 87%

Section: Resultsmentioning

confidence: 73%

See 1 more Smart Citation

Examining the Wind Shear Theory of Sporadic E With ICON/MIGHTI Winds and COSMIC‐2 Radio Occultation Data

Yamazaki

Arras

Andoh

et al. 2021

Geophysical Research Letters

Self Cite

View full text Add to dashboard Cite

show abstract

“…Thus, the diurnal appearance of Es layers, LDLs, can be seen below 110 km around Arecibo. In contrast, LDLs are rarely seen in simulations at the mid‐latitudes (Andoh et al., 2021). Andoh et al.…”

Section: Resultsmentioning

confidence: 99%

“…Andoh et al. (2021) showed that the vertical winds could modify the structures of the Es layers below 100 km at the mid‐latitudes. The simulated LDLs at Arecibo descend to ∼95 km with the phase of diurnal tides and then disappear, due to three‐body reactions of metal ions, before modifying their structures intensely by the vertical winds.…”

Section: Resultsmentioning

confidence: 99%

Numerical Simulations on Day‐to‐Day Variations of Low‐Latitude Es Layers at Arecibo

Andoh

Saito

Shinagawa

2022

Geophysical Research Letters

Self Cite

View full text Add to dashboard Cite

To reveal mechanisms of day‐to‐day variations of the low‐latitude sporadic E (Es) layers, Es layer simulations were performed and compared to plasma layers observed by the Arecibo radar. Many studies have been conducted about the Es layers till now. However, few studies investigated the day‐to‐day variations of the Es layers especially at the low‐latitudes. Herein, for the first time, our numerical model generally succeeded in reproducing features of the day‐to‐day variations of the low‐latitude Es layers. We found that the day‐to‐day variations of the Es layers are created by a combination of day‐to‐day variations of zonal/meridional‐wind shears driven by the tides and the downward phase velocity of the tides. The wind‐driven mechanism generally explains the day‐to‐day variations of the low‐latitude Es layers.

show abstract

The possible effect of turbopause on formation of mid-latitude sporadic E layers

Zhang,

Hu,

et al. 2024

Advances in Space Research

View full text Add to dashboard Cite

Temporal Evolution of Three‐Dimensional Structures of Metal Ion Layer Around Japan Simulated by a Midlatitude Ionospheric Model

Abstract: The layered structure of metal ions formed in the lower ionosphere, called the metal ion layer (MIL), has recently attracted the attention of researchers (

Cited by 15 publications

References 52 publications

Examining the Wind Shear Theory of Sporadic E With ICON/MIGHTI Winds and COSMIC‐2 Radio Occultation Data

Examining the Wind Shear Theory of Sporadic E With ICON/MIGHTI Winds and COSMIC‐2 Radio Occultation Data

Numerical Simulations on Day‐to‐Day Variations of Low‐Latitude Es Layers at Arecibo

The possible effect of turbopause on formation of mid-latitude sporadic E layers

Contact Info

Product

Resources

About