11 research outputs found
Photospheric Magnetic Field: Relationship Between North-South Asymmetry and Flux Imbalance
Photospheric magnetic fields were studied using the Kitt Peak synoptic maps
for 1976-2003. Only strong magnetic fields (B>100 G) of the equatorial region
were taken into account. The north-south asymmetry of the magnetic fluxes was
considered as well as the imbalance between positive and negative fluxes. The
north-south asymmetry displays a regular alternation of the dominant hemisphere
during the solar cycle: the northern hemisphere dominated in the ascending
phase, the southern one in the descending phase during Solar Cycles 21-23. The
sign of the imbalance did not change during the 11 years from one polar-field
reversal to the next and always coincided with the sign of the Sun's polar
magnetic field in the northern hemisphere. The dominant sign of leading
sunspots in one of the hemispheres determines the sign of the magnetic-flux
imbalance. The sign of the north-south asymmetry of the magnetic fluxes and the
sign of the imbalance of the positive and the negative fluxes are related to
the quarter of the 22-year magnetic cycle where the magnetic configuration of
the Sun remains constant (from the minimum where the sunspot sign changes
according to Hale's law to the magnetic-field reversal and from the reversal to
the minimum). The sign of the north-south asymmetry for the time interval
considered was determined by the phase of the 11-year cycle (before or after
the reversal); the sign of the imbalance of the positive and the negative
fluxes depends on both the phase of the 11-year cycle and on the parity of the
solar cycle. The results obtained demonstrate the connection of the magnetic
fields in active regions with the Sun's polar magnetic field in the northern
hemisphere.Comment: 24 pages, 12 figures, 2 table
Theoretical and Experimental Studies of the Rigidity Spectrum of the 27-Day Variation of the Galactic Cosmic Ray Intensity in Different Epochs of Solar Activity
Photospheric Magnetic Field: Relationship Between North–South Asymmetry and Flux Imbalance
Different space weather effects in anomalies of the high and low orbital satellites
Preliminary results of the EU INTAS Project 00810, which aims to improve the methods of safeguarding satellites in the Earth's
magnetosphere from the negative effects of the space environment, are presented. Anomaly data from the ‘‘Kosmos’’ series satellites
in the period 1971–1999 are combined in one database, together with similar information on other spacecraft. This database contains,
beyond the anomaly information, various characteristics of the space weather: geomagnetic activity indices (Ap, AE and Dst),
fluxes and fluences of electrons and protons at different energies, high energy cosmic ray variations and other solar, interplanetary
and solar wind data. A comparative analysis of the distribution of each of these parameters relative to satellite anomalies was carried
out for the total number of anomalies (about 6000 events), and separately for high (~5000 events) and low (about 800 events) altitude
orbit satellites. No relation was found between low and high altitude satellite anomalies. Daily numbers of satellite anomalies,
averaged by a superposed epoch method around sudden storm commencements and proton event onsets for high (>1500 km) and
low (<1500 km) altitude orbits revealed a big difference in a behavior. Satellites were divided on several groups according to the
orbital characteristics (altitude and inclination). The relation of satellite anomalies to the environmental parameters was found
to be different for various orbits that should be taken into account under developing of the anomaly frequency models.
© 2004 COSPAR. Published by Elsevier Ltd. All rights reserved