Coordinated sporadic E layer observations made with Chung-Li 30MHz radar, ionosonde and FORMOSAT-3/COSMIC satellites

Chu, Yen Hsyang; Brahmanandam, P. S.; Wang, Chien Ya; Su, Ching Lun; Kuong, Ruey Ming

doi:10.1016/j.jastp.2010.10.004

Cited by 42 publications

(36 citation statements)

References 40 publications

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“…(8)) of the AGW evolving in the horizontal shear flow are consistent with results given byChu et al, (2011). According toChu et al (2011) the observed vertical shears of the radar Doppler velocity in the Es layers were due to the upward propagating gravity waves with vertical wavelength of approximately 10-20 km and mean period of about 5-6 min. Note that to characterize AGW that evolves in the horizontal shear flow and causes the formation of Es layers (see Figs 6-7) we can use dispersion relation, Eq.…”

supporting

confidence: 88%

Formation of sporadic-E (Es) layers under the influence of AGWs evolving in a horizontal shear flow

Didebulidze

Dalakishvili

Lomidze

et al. 2015

Journal of Atmospheric and Solar-Terrestrial Physics

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supporting

confidence: 88%

Formation of sporadic-E (Es) layers under the influence of AGWs evolving in a horizontal shear flow

Didebulidze

Dalakishvili

Lomidze

et al. 2015

Journal of Atmospheric and Solar-Terrestrial Physics

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“…Another important characteristic of our observed FAIs is the periodic Doppler fluctuation. The oscillations in the Doppler velocity are associated with the modulation of the gravity waves and the wave‐induced polarization electric fields [ Chu et al ., ]. A wave‐like structure was observed at the altitude from approximately 100 to 115 km in Sporadic E Experiment over Kyushu 2 (SEEK‐2) experiment [ Larsen et al ., ], implying that the KH instability, the E s layer instability, or the gravity wave‐induced polarization electric field possibly constructed the quasiperiodic structures [ Pfaff et al ., ].…”

Section: Discussionmentioning

confidence: 99%

Daytime E region field‐aligned irregularities observed during a solar eclipse

Chen

Zhao

et al. 2014

JGR Space Physics

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The driving mechanism of the midlatitude field-aligned irregularities (FAIs) has been in dispute for many years. The experimental observations were carried out during the solar eclipse of 22 July 2009 in Wuhan, China, to study the possibility of the wave-driven irregularities. A high-frequency coherent scatter radar was used to detect the E region irregularities. An ionosonde was applied to record the trace of gravity waves in ionosphere. The E region FAIs occurred at the end of the solar eclipse with fluctuant Doppler. At the same time, the oscillations on the fE s (maximum reflecting frequency of E s ) curve and in the Doppler velocity of the echoes from the E s layer were also recorded. The data analysis and comparison show that the gravity waves and the FAIs occurred at the same time with the in-phase variations in amplitude and phase. Thus, the solar eclipse and the gravity waves may play important roles in the occurrence of the irregularities. A schematic diagram of one-period gravity wave is used to explain the possible gravity wave-driven mechanism and the Doppler fluctuation in the irregularities. The daytime FAI in midlatitude is a rare phenomenon, even in the condition of solar eclipse. There are only four cases of the E region FAIs observed during a solar eclipse, including our observations. The unique feature of our observations is the synchronized oscillations in the irregularities and in the E s layer, which will help address the outstanding question of the source of the midlatitude E region FAIs.

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“…Widely accepted generation mechanisms of Es under the presence of vertical shear of zonal winds include atmospheric gravity waves Didebulidze and Lomidze 2010;Chu et al 2011;Liu et al 2014), shear instability (Larsen 2000;Bernhardt 2002;Larsen et al 2007;Hysell et al 2009), and the Es-layer instability Tsunoda 2002, 2004). At the moment, it is difficult to tell which mechanism is dominant because of the scarcity of observed cases.…”

Section: Introductionmentioning

confidence: 99%

Morphology and dynamics of daytime mid-latitude sporadic-E patches revealed by GPS total electron content observations in Japan

Maeda

Heki

2015

Earth Planet Sp

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Morphological characteristics of daytime mid-latitude sporadic-E (Es) patches are studied by two-dimensional total electron content (TEC) maps drawn using the Japanese dense network of Global Positioning System (GPS) receivers. By analyzing over 70 cases, we found that their horizontal shapes are characterized by frontal structure typically elongated in east-west by~100 km. They are observed to migrate mainly northward in the morning and southward in the afternoon with speeds of 30-100 m/s. This may reflect the velocities of neutral winds controlled by the atmospheric tides. Such frontal structures are often found to include smaller scale structures.

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Coordinated sporadic E layer observations made with Chung-Li 30MHz radar, ionosonde and FORMOSAT-3/COSMIC satellites

Cited by 42 publications

References 40 publications

Formation of sporadic-E (Es) layers under the influence of AGWs evolving in a horizontal shear flow

Formation of sporadic-E (Es) layers under the influence of AGWs evolving in a horizontal shear flow

Daytime E region field‐aligned irregularities observed during a solar eclipse

Morphology and dynamics of daytime mid-latitude sporadic-E patches revealed by GPS total electron content observations in Japan

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