scholarly journals Anomalies in Ionosonde Records Due to Travelling Ionospheric Disturbances

1958 ◽  
Vol 11 (1) ◽  
pp. 79 ◽  
Author(s):  
LH Heisler
Keyword(s):  
Seasonal Distribution ◽  
Ionospheric Disturbances ◽  
Travelling Ionospheric Disturbances ◽  
F Region

Anomalies which frequently appear on ionosonde records of the F region during the passage of travelling disturbances are classified into four main types; and the diurnal and seasonal distribution of their occurrence is discussed.

scholarly journals A study of atmospheric gravity waves and travelling ionospheric disturbances at equatorial latitudes

1997 ◽  
Vol 15 (8) ◽  
pp. 1048-1056 ◽  
Author(s):  
R. L. Balthazor ◽  
R. J. Moffett
Keyword(s):  
Gravity Waves ◽  
Large Scale ◽  
Ionospheric Disturbance ◽  
Magnetic Equator ◽  
Ionospheric Disturbances ◽  
Atmospheric Gravity Waves ◽  
Opposite Hemisphere ◽  
Travelling Ionospheric Disturbances ◽  
F Region ◽  
Atmospheric Gravity

Abstract. A global coupled thermosphere-ionosphere-plasmasphere model is used to simulate a family of large-scale imperfectly ducted atmospheric gravity waves (AGWs) and associated travelling ionospheric disturbances (TIDs) originating at conjugate magnetic latitudes in the north and south auroral zones and subsequently propagating meridionally to equatorial latitudes. A 'fast' dominant mode and two slower modes are identified. We find that, at the magnetic equator, all the clearly identified modes of AGW interfere constructively and pass through to the opposite hemisphere with unchanged velocity. At F-region altitudes the 'fast' AGW has the largest amplitude, and when northward propagating and southward propagating modes interfere at the equator, the TID (as parameterised by the fractional change in the electron density at the F2 peak) increases in magnitude at the equator. The amplitude of the TID at the magnetic equator is increased compared to mid-latitudes in both upper and lower F-regions with a larger increase in the upper F-region. The ionospheric disturbance at the equator persists in the upper F-region for about 1 hour and in the lower F-region for 2.5 hours after the AGWs first interfere, and it is suggested that this is due to enhancements of the TID by slower AGW modes arriving later at the magnetic equator. The complex effects of the interplays of the TIDs generated in the equatorial plasmasphere are analysed by examining neutral and ion winds predicted by the model, and are demonstrated to be consequences of the forcing of the plasmasphere along the magnetic field lines by the neutral air pressure wave.

A Discussion on the early days of ionospheric research and the theory of electric and magnetic waves in the ionosphere and magnetosphere - Early work in Australia, New Zealand and at the Halley Stewart Laboratory, London

1975 ◽  
Vol 280 (1293) ◽  
pp. 35-46
Keyword(s):  
Magnetic Field ◽  
New Zealand ◽  
University Research ◽  
Ionospheric Disturbances ◽  
Pulse Technique ◽  
Postgraduate Students ◽  
Travelling Ionospheric Disturbances ◽  
F Region ◽  
King's College ◽  
Profound Influence

Ionospheric research began in Australia in 1927 after the formation of the Radio Research Board. A. L. Green, by measuring polarization of downcoming waves travelling in the opposite direction to the Earth’s magnetic field confirmed that electrons were the effective particles. Builder, Pulley and Wood designed equipment for the automatic recording of critical frequencies. Martyn & Pulley found evidence for high temperatures at F region levels. Munro discovered travelling ionospheric disturbances. In New Zealand the earliest measurements were made by Munro in 1927—8. The New Zealand Radio Research Board later supported the measurement of critical frequencies, absorption and collisional frequency of Peddie, White, Banwell and Straker. Australian and New Zealand postgraduate students contributed to Appleton’s group at King’s College and at the Halley Stewart Laboratory, London. Builder introduced the pulse technique and took part in the Polar Year (1932-3) expedition to Tromso. Pulley designed the first manual ionogram equipment. Both returned to work in Sydney. White measured reflexion coefficients and collisional frequencies of electrons and later returned to Canterbury University, New Zealand. The early ionospheric researches sponsored by the Australian and New Zealand Research Boards had a profound influence by expanding university research and the training of many postgraduate students.

scholarly journals Travelling Ionospheric Disturbances in the F Region

1958 ◽  
Vol 11 (1) ◽  
pp. 91 ◽  
Author(s):  
GH Munro
Keyword(s):  
Seasonal Variation ◽  
Radio Frequency ◽  
Diurnal Variation ◽  
Diurnal Variations ◽  
Ionospheric Disturbances ◽  
Frequency Of Occurrence ◽  
Travelling Ionospheric Disturbances ◽  
F Region ◽  
Seasonal And Diurnal Variations ◽  
Single Radio

Observations of the horizontal movements of travelling ionospheric disturbances recorded on a single radio frequency from April 1948 to March 1957 are analysed for seasonal and diurnal variations of occurrence and of direction and speed of travel. Recording was mainly in daylight hours but some limited night results are included. The average number of disturbances recorded was six per day over the period. Observing accuracy and significance of the deduced data are discussed. The frequency of occurrence has a diurnal variation with a marked midday maximum and a seasonal variation with minima at the equinoxes.

Discussion on the papers on atmospheric sciences

1977 ◽  
Vol 279 (963) ◽  
pp. 287-288
Keyword(s):  
Electric Fields ◽  
Gravity Waves ◽  
Ionospheric Disturbances ◽  
Vertical Movements ◽  
Atmospheric Sciences ◽  
Travelling Ionospheric Disturbances ◽  
F Region ◽  
Sudden Commencements ◽  
The Antarctic ◽  
Auroral Particle Precipitation

W. R. Piggott Although Dr Dudeney’s paper presents some preliminary results from the h.f. Doppler experiment in the Antarctic Peninsula which are interesting in themselves, the main objective of deploying the experiment in this part of the world was to take advantage of the special geophysical situation in the sector for a broader investigation. Our objectives included: ( a ) to study the relations between gravity waves and travelling ionospheric disturbances. ( b ) to see whether gravity waves could be associated with major weather systems, or with particular types of auroral particle precipitation. ( c ) to investigate whether F-region winds are modified during periods of auroral activity. ( d ) to search for possible F-region movements associated with magnetic field changes, e.g. sudden commencements. ( e ) if electric fields exist in the F-region in this zone, vertical movements due to them should be particularly easy to detect. The experiment thus forms part of the general British Antarctic Survey’s attack on the dynamics of the F-region.

The Observation of Large Scale Travelling Ionospheric Disturbances Based on GPS Network

2002 ◽  
Vol 45 (4) ◽  
pp. 469-475 ◽  
Author(s):  
Dong-He ZHANG ◽  
K. Igarashi ◽  
Zuo XIAO ◽  
Guan-Yi MA
Keyword(s):  
Large Scale ◽  
Ionospheric Disturbances ◽  
Travelling Ionospheric Disturbances ◽  
Gps Network
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