A study of the relation between ionospheric absorption and predicted HF propagation parameters at high latitudes

1994 ◽  
Author(s):  
V. Jodalen
Keyword(s):  
High Latitudes ◽  
Ionospheric Absorption ◽  
Hf Propagation ◽  
Propagation Parameters

Updated climatological model predictions of ionospheric and HF propagation parameters

Radio Science ◽  
1991 ◽  
Vol 26 (4) ◽  
pp. 1017-1024 ◽  
Author(s):  
M. H. Reilly ◽  
F. J. Rhoads ◽  
J. M. Goodman ◽  
M. Singh
Keyword(s):  
Model Predictions ◽  
Hf Propagation ◽  
Propagation Parameters ◽  
Climatological Model

Modeling of HF propagation at high latitudes on the basis of IRI

2016 ◽  
Vol 57 (3) ◽  
pp. 821-834 ◽  
Author(s):  
D.V. Blagoveshchensky ◽  
O.A. Maltseva ◽  
M.M. Anishin ◽  
D.D. Rogov ◽  
M.A. Sergeeva
Keyword(s):  
High Latitudes ◽  
Hf Propagation

A study of ionospheric absorption events at very high latitudes

1976 ◽  
Vol 38 (12) ◽  
pp. 1289-1297 ◽  
Author(s):  
J Vassal ◽  
J.J Berthelier ◽  
J Lavergnat ◽  
M Sylvain
Keyword(s):  
High Latitudes ◽  
Ionospheric Absorption ◽  
Very High

scholarly journals Peculiarities of the behavior of the ionosphere and HF propagation parameters in September 2017

2018 ◽  
Author(s):  
Donat Blagoveshchensky ◽  
Olga Maltseva ◽  
Tatyana Nikitenko ◽  
Gennady Zhbankov
Keyword(s):  
Hf Propagation ◽  
Propagation Parameters

Motions of neutral hydrogen at high latitudes

1967 ◽  
Vol 31 ◽  
pp. 265-278 ◽  
Author(s):  
A. Blaauw ◽  
I. Fejes ◽  
C. R. Tolbert ◽  
A. N. M. Hulsbosch ◽  
E. Raimond
Keyword(s):  
Surface Density ◽  
Velocity Dispersion ◽  
Neutral Hydrogen ◽  
Hydrogen Gas ◽  
High Latitudes ◽  
Low Velocity

Earlier investigations have shown that there is a preponderance of negative velocities in the hydrogen gas at high latitudes, and that in certain areas very little low-velocity gas occurs. In the region 100° <l< 250°, + 40° <b< + 85°, there appears to be a disturbance, with velocities between - 30 and - 80 km/sec. This ‘streaming’ involves about 3000 (r/100)2solar masses (rin pc). In the same region there is a low surface density at low velocities (|V| < 30 km/sec). About 40% of the gas in the disturbance is in the form of separate concentrations superimposed on a relatively smooth background. The number of these concentrations as a function of velocity remains constant from - 30 to - 60 km/sec but drops rapidly at higher negative velocities. The velocity dispersion in the concentrations varies little about 6·2 km/sec. Concentrations at positive velocities are much less abundant.

Long-term Cyclic Variations of Prominences, Green and Red Coronae over Solar Cycles

2000 ◽  
Vol 179 ◽  
pp. 201-204
Author(s):  
Vojtech Rušin ◽  
Milan Minarovjech ◽  
Milan Rybanský
Keyword(s):  
Emission Lines ◽  
High Latitudes ◽  
Green Line ◽  
Solar Cycles ◽  
The South ◽  
Coronal Emission ◽  
Local Maxima ◽  
The North ◽  
Cyclic Variations

AbstractLong-term cyclic variations in the distribution of prominences and intensities of green (530.3 nm) and red (637.4 nm) coronal emission lines over solar cycles 18–23 are presented. Polar prominence branches will reach the poles at different epochs in cycle 23: the north branch at the beginning in 2002 and the south branch a year later (2003), respectively. The local maxima of intensities in the green line show both poleward- and equatorward-migrating branches. The poleward branches will reach the poles around cycle maxima like prominences, while the equatorward branches show a duration of 18 years and will end in cycle minima (2007). The red corona shows mostly equatorward branches. The possibility that these branches begin to develop at high latitudes in the preceding cycles cannot be excluded.

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