The influence of 10.7-cm solar-flux variations on midlatitude daytime ionospheric disturbance conditions

1996 ◽  
Vol 101 (A5) ◽  
pp. 10849-10854 ◽  
Author(s):  
G. G. Bowman
Keyword(s):  
Ionospheric Disturbance ◽  
Solar Flux ◽  
10.7 Cm Solar Flux

Solar cycle and seasonal variations in F-region vertical drifts over Kodaikanal, India

1995 ◽  
Vol 13 (6) ◽  
pp. 633-640 ◽  
Author(s):  
K. B. Ramesh ◽  
J. H. Sastri
Keyword(s):  
Solar Activity ◽  
Solar Cycle ◽  
Seasonal Variations ◽  
Normal Incidence ◽  
Magnetic Activity ◽  
Solar Flux ◽  
Seasonal Trend ◽  
F Region ◽  
Phase Path ◽  
10.7 Cm Solar Flux

Abstract. Measurements of the changes in phase path of F-region reflections at normal incidence at Kodaikanal (77° 28'E, 10° 14'N, dip 3°N) from February 1991 to February 1993 are used to determine the variation of the equatorial evening F-region vertical drifts (V z) with season, solar and magnetic activity. It is found that on average, at Kodaikanal, the post-sunset peak in Vz(Vzp) is higher in equinox and local winter months than in local summer. The day-to-day variability in V zp is highest in summer and lowest in winter. This seasonal trend persists even on magnetically quiet days (Ap \\leq14). Vzp is found to increase with 10.7 cm solar flux in all three seasons but tends to saturate for large flux values (>230 units) during local summer and winter months. Magnetic activity [represented by Ap as well as the time-weighted accumulations of a p and ap (τ)] does not seem to have any statistically significant effect on Vzp , except during equinoctial months of moderate solar activity, when Vzp decreases as magnetic activity increases.

The 10.7-cm Solar Flux and the 26-Month Oscillation

1966 ◽  
Vol 23 (3) ◽  
pp. 314-319 ◽  
Author(s):  
A. D. Belmont ◽  
D. G. Dartt ◽  
M. S. Ulstad
Keyword(s):  
Solar Flux ◽  
10.7 Cm Solar Flux

On the relationship between the 10.7 cm solar flux, surface pressure and air temperature over Greece

1992 ◽  
Vol 46 (1) ◽  
pp. 27-32 ◽  
Author(s):  
C. A. Varotsos ◽  
N. A. Dris ◽  
D. N. Asimakopoulos ◽  
C. Cartalis
Keyword(s):  
Air Temperature ◽  
Surface Pressure ◽  
Solar Flux ◽  
Flux Surface ◽  
The Relationship ◽  
10.7 Cm Solar Flux

scholarly journals Rate of change of total column ozone and monsoon rainfall - A co-variation with the variable component of 10.7 cm solar flux during pre-monsoon period

MAUSAM ◽  
2021 ◽  
Vol 62 (1) ◽  
pp. 91-96
Author(s):  
S. K. MIDYA ◽  
U. SAHA
Keyword(s):  
Monsoon Rainfall ◽  
Rate Of Change ◽  
Solar Flux ◽  
Variable Component ◽  
Monsoon Period ◽  
Total Column Ozone ◽  
Different Seasons ◽  
Positive Correlations ◽  
Column Ozone ◽  
10.7 Cm Solar Flux

A critical analysis is done on the variation of the rate of change of Total Column Ozone (TCO) over Dum Dum (22° 38 N, 88° 26 E) and Total Monsoon Rainfall over Gangetic West Bengal with the variable component of 10.7 cm solar flux during different seasons for the period 1997- 2005. An anti-correlation is observed between the variable component with the rate of change of TCO during the pre-monsoon and monsoon period and significant positive correlations during the post-monsoon and winter seasons. Quite insignificant positive correlations are observed between the variable component and Total Monsoon Rainfall during different seasons for this period. A co-variation is observed with the increase in the variable component of 10.7 cm solar flux throughout the period of study only during the pre-monsoon season. Possible explanations are also presented.

scholarly journals Solar flux dependence of coherence scales in scintillation patterns produced by ESF irregularities

2005 ◽  
Vol 23 (10) ◽  
pp. 3261-3266 ◽  
Author(s):  
B. Engavale ◽  
K. Jeeva ◽  
K. U. Nair ◽  
A. Bhattacharyya
Keyword(s):  
Initial Phase ◽  
General Trend ◽  
Linear Increase ◽  
Solar Flux ◽  
Radio Waves ◽  
Spread F ◽  
Decorrelation Scale ◽  
10.7 Cm Solar Flux ◽  
East West ◽  
Scale Length

Abstract. The coherence scale length, defined as the 50% decorrelation scale length along the magnetic east-west direction, in the ground scintillation pattern obtained at a dip equatorial location, due to scattering of VHF radio waves by equatorial spread F (ESF) irregularities, is calculated, using amplitude scintillation data recorded by two spaced receivers. The average east-west drift of the ground scintillation pattern, during the pre- and post-midnight periods, also calculated from the same observations, shows an almost linear increase with 10.7-cm solar flux. In the present paper the variability of the drift is automatically taken into account in the calculation of the coherence scale length of the ground scintillation pattern. For weak scintillations, the coherence scale depends on the Fresnel scale, which varies with the height of the irregularity layer, and also on the spectral index of the irregularity power spectrum. It is found that for weak scintillations, the coherence scales are much better organized according to the 10.7-cm solar flux, during the pre-midnight period, than during the post-midnight period, with a general trend of coherence scale length increasing with 10.7-cm solar flux except for cases with F 10.7-cm solar flux <100. This indicates that, during the initial phase of ESF irregularity development, the irregularity spectrum does not have much variability while further evolution of the spatial structure in ESF irregularities is controlled by factors other than the solar flux.

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