الفهرس 
ContentsOnly 14 pages are availabe for public view
 |  | from | 16 |  |  |
| | | from | 16 | | |
Abstract
There are many researchers studied the effect of changing the magnetic polarity from north
to south or from south to north on the solar geomagnetic parameters such as (solar wind
speed (SWS), ion density (n), sunspot number (Rz), geomagnetic indicies (Kp and Ap),
solar radio flux (SF), and cosmic ray intensity (CRI) ) for many years; however, there are
still open questions. The thesis contains four chapters, Conclusions, (127) references,
English and Arabic summeries and the publication.
Chapter (1):-
This chapter introduces a general introduction contain:
1- magnetic field (IMF)
2- Interplanetary medium
3- Heliospheric current sheet (HCS)
4- Geomagnetic indices (Kp and Ap)
5- Cosmic rays (CR)
6- Aim of work
Chapter (2):-
This chapter contains main points about:
1-The sources of our data which are used in our study
2-Data treatments
3-Data analysis
Chapter (3):-
This chapter represents the study of the north-south asymmetry in solar, interplanetary and
geomagnetic indices. Data of interplanetary plasma (field magnitude, solar wind speed and
ion density), solar (sunspot number and solar radio flux), and geomagnetic indices (Kp and
Ap) over the period 1970–2010, have been used to examine the asymmetry between the
solar field north and south of the heliospheric current sheet (HCS). By separating the
hourly average values of IMF data according to the field polarity sense (away or toward),
we have calculated the daily averages of considered parameters. A persistent yearly northsouth
asymmetry of the field magnitude is clear over the considered period.
Chapter (4):-
To examine the dependence of the N-S asymmetry of cosmic-ray intensity variation (CRI
% ), at different rigidities and latitudes, on the IMF polarities (qA > 0 and qA < 0), we
classified the former period into five subsets; three sets for negative (1964-1968, 1981-
1988 and 2001-2008) and the other sets for positive magnetic polarity (1971-1978 and
1991-1998). Thus, each subset contains 8 years, after removing the years during which the
Sun’s polar field was reversing.
Ten neutron monitor measurements arranged according to the increasing in the cut-off rigidity over the period 1964-2012. The time interval covers several epochs of solar activity maxima, minima, and polar field reversals. The annual average cosmic ray solar
diurnal variations were separated into toward and away sectors of the IMF. The median
primary rigidities of response for these detectors cover the range 10 GV ≤ Rm ≤ 33 GV .
The yearly averages of the CRI variation difference between the two sectors are
determined to examine the north-south asymmetry of solar variations during the epochs of
asymmetry in the solar activity, as well as during epochs of positive and negative polarities
of the Sun’s magnetic field. Error estimates for the difference in variations were determined
by the standard technique of error propagation.