Daytime Mesosphere and Lower Thermosphere Neutral Winds and their relationship with lower E region layers over Arecibo

Abstract. The main purpose of this study is to investigate the vertical coupling between the mesosphere and lower thermosphere (MLT) region and the ionosphere through ultra-fast Kelvin (UFK) waves in the equatorial atmosphere. The effect of UFK waves on the ionospheric parameters was estimated using an ionospheric model which calculates electrostatic potential in the E-region and solves coupled electrodynamics of the equatorial ionosphere in the E- and F-regions. The UFK wave was observed in the South American equatorial region during February–March 2005. The MLT wind data obtained by meteor radar at São João do Cariri (7.5° S, 37.5° W) and ionospheric F-layer bottom height (h'F) observed by ionosonde at Fortaleza (3.9° S; 38.4° W) were used in order to calculate the wave characteristics and amplitude of oscillation. The simulation results showed that the combined electrodynamical effect of tides and UFK waves in the MLT region could explain the oscillations observed in the ionospheric parameters.

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Foil chaff ejection systems for rocket-borne measurement of neutral winds in the mesosphere and lower thermosphere

Review of Scientific Instruments ◽

10.1063/1.1765755 ◽

2004 ◽

Vol 75 (7) ◽

pp. 2346-2350 ◽

Cited By ~ 4

Author(s):

Yoshiko Koizumi ◽

Manabu Shimoyama ◽

Koh-Ichiro Oyama ◽

Yasuhiro Murayama ◽

Toshitaka Tsuda ◽

...

Keyword(s):

Lower Thermosphere ◽

Neutral Winds ◽

Mesosphere And Lower Thermosphere

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The upper atmospheric responses to tidal and planetary waves

10.5194/egusphere-egu2020-12350 ◽

2020 ◽

Author(s):

Sheng-Yang Gu

Keyword(s):

Planetary Wave ◽

Lower Thermosphere ◽

Satellite System ◽

Planetary Waves ◽

Spatial Structures ◽

Ionospheric Effect ◽

Ion Drift ◽

E Region ◽

Mesosphere And Lower Thermosphere ◽

Tide Interaction

<p>Tidal and planetary waves (PWs) in the mesosphere and lower thermosphere region could have significant impact on the upper thermosphere/ionosphere system through direct propagations, E region wind dynamo, and the change of residual circulations. We would like to show some results from BeiDou and COSMIC observations, as well as TIME-GCM simulations, to illustrate the lower/upper atmospheric couplings through different mechanisms. Generally, the spatial structures of the ionospheric responses to planetary waves agree with the ionospheric fountain effect, which indicates the important roles of equatorial wind dynamos in transmitting planetary wave signals to the ionosphere. The TIME-GCM simulations show that the zonal and meridional components of the planetary waves could result in evident vertical ion drift perturbations, while the net ionospheric effect is related to both their latitudinal structures and phases. The simulations also show that the change of tidal amplitudes and secondary PWs generated by PW-tide interaction are also important to the ionospheric variabilities. Besides, the couplings through PW-induced residual circulations are exhibited by both model simulations and TEC observations from BeiDou satellite system.</p>

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First simultaneous lidar observations of sodium layers and VHF radar observations of E-region field-aligned irregularities at the low-latitude station Gadanki

Annales Geophysicae ◽

10.5194/angeo-27-3411-2009 ◽

2009 ◽

Vol 27 (9) ◽

pp. 3411-3419 ◽

Cited By ~ 5

Author(s):

S. Sridharan ◽

A. K. Patra ◽

N. Venkateswara Rao ◽

G. Ramkumar

Keyword(s):

Lower Thermosphere ◽

Low Latitude ◽

Vhf Radar ◽

Neutral Winds ◽

Zonal Winds ◽

Tidal Phase ◽

E Region ◽

The Relationship ◽

Lidar Observations ◽

Field Aligned Irregularities

Abstract. Simultaneous observations of atmospheric sodium (Na) made by a resonance lidar and E-region field-aligned-irregularities (FAI) made by the Indian MST radar, both located at Gadanki (13.5° N, 79.2° E) and horizontal winds acquired by a SKiYMET meteor radar at Trivandrum (8.5° N, 77° E) are used to investigate the relationship among sodium layer, FAI and neutral winds in the mesosphere and lower thermosphere region. The altitudes and descent rates of higher altitude (~95 km) Na layer and FAI agree quite well. The descending structures of the higher altitude Na layer and FAI are found to be closely related to the diurnal tidal phase structure in zonal winds observed over Trivandrum. At lower altitudes, the descent rate of FAI is larger than that of Na layer and zonal tidal phase. These observations support the hypothesis that the metallic ion layers are formed by the zonal wind shear associated with tidal winds and subsequently get neutralized to manifest in the form of descending Na layers. The descending FAI echoing layers are manifestation of the instabilities setting in on the ionization layer. In the present observations, the altitudes of occurrence of Na layer and FAI echoes being low, we surmise that it is quite possible that the FAI echoes are due to the descent of already formed irregularities at higher altitudes.

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Neutral winds and temperature in the tropical mesosphere and lower thermosphere during January 1993: Observation and comparison with TIME-GCM results

Journal of Geophysical Research Atmospheres ◽

10.1029/97ja00439 ◽

1997 ◽

Vol 102 (A6) ◽

pp. 11507-11519 ◽

Cited By ~ 23

Author(s):

Q. H. Zhou ◽

M. P. Sulzer ◽

C. A. Tepley ◽

C. G. Fesen ◽

R. G. Roble ◽

...

Keyword(s):

Lower Thermosphere ◽

Neutral Winds ◽

Mesosphere And Lower Thermosphere

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A comparison of mesosphere and lower thermosphere neutral winds as determined by meteor and medium-frequency radar at 70°N

Radio Science ◽

10.1029/2004rs003102 ◽

2005 ◽

Vol 40 (4) ◽

pp. n/a-n/a ◽

Cited By ~ 16

Author(s):

C. M. Hall ◽

T. Aso ◽

M. Tsutsumi ◽

S. Nozawa ◽

A. H. Manson ◽

...

Keyword(s):

Lower Thermosphere ◽

Medium Frequency ◽

Neutral Winds ◽

Mesosphere And Lower Thermosphere

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Large-Scale Waves in the Mesosphere and Lower Thermosphere Observed by SABER

Journal of the Atmospheric Sciences ◽

10.1175/jas3612.1 ◽

2005 ◽

Vol 62 (12) ◽

pp. 4384-4399 ◽

Cited By ~ 104

Author(s):

Rolando R. Garcia ◽

Ruth Lieberman ◽

James M. Russell ◽

Martin G. Mlynczak

Keyword(s):

Large Scale ◽

Middle Atmosphere ◽

Lower Thermosphere ◽

Normal Modes ◽

Zonal Winds ◽

Broadband Emission ◽

Summer Hemisphere ◽

Mean Structure ◽

Mesosphere And Lower Thermosphere ◽

The Tropics

Abstract Observations made by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on board NASA’s Thermosphere–Ionosphere–Mesosphere Energetics and Dynamics (TIMED) satellite have been processed using Salby’s fast Fourier synoptic mapping (FFSM) algorithm. The mapped data provide a first synoptic look at the mean structure and traveling waves of the mesosphere and lower thermosphere (MLT) since the launch of the TIMED satellite in December 2001. The results show the presence of various wave modes in the MLT, which reach largest amplitude above the mesopause and include Kelvin and Rossby–gravity waves, eastward-propagating diurnal oscillations (“non-sun-synchronous tides”), and a set of quasi-normal modes associated with the so-called 2-day wave. The latter exhibits marked seasonal variability, attaining large amplitudes during the solstices and all but disappearing at the equinoxes. SABER data also show a strong quasi-stationary Rossby wave signal throughout the middle atmosphere of the winter hemisphere; the signal extends into the Tropics and even into the summer hemisphere in the MLT, suggesting ducting by westerly background zonal winds. At certain times of the year, the 5-day Rossby normal mode and the 4-day wave associated with instability of the polar night jet are also prominent in SABER data.

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