Geomagnetism during solar cycle 23: Characteristics

Abstract

On the basis of more than 48 years of morphological analysis of yearly and monthly values of the sunspot number, the aa index, the solar wind speed and interplanetary magnetic field, we point out the particularities of geomagnetic activity during the period 1996–2009. We especially investigate the last cycle 23 and the long minimum which followed it. During this period, the lowest values of the yearly averaged IMF (3 nT) and yearly averaged solar wind speed (364 km/s) are recorded in 1996, and 2009 respectively. The year 2003 shows itself particular by recording the highest value of the averaged solar wind (568 km/s), associated to the highest value of the yearly averaged aa index (37 nT). We also find that observations during the year 2003 seem to be related to several coronal holes which are known to generate high-speed wind stream. From the long time (more than one century) study of solar variability, the present period is similar to the beginning of twentieth century. We especially present the morphological features of solar cycle 23 which is followed by a deep solar minimum.

Solar Activity and Meteorological Fluctuations in West Africa: Temperatures and Pluviometry in Burkina Faso, 1970-2012

“…Placing now our study in the context of solar cycle phases (Minimum, Increasing, Maximum, and Decreasing) and geomagnetic classification proposed by Zerbo et al [7], we made interesting analysis: 1) During Minimum phase where Quiet activity (QA) is predominant [6][7][8], precipitations increase (Figure 1) and temperatures decreases (Figure 2). This phase is characterized by slow solar wind speed and high density of solar plasma 2) During Maximum phase where Shock Activity (SA) is predominant [6][7][8], precipitations increase (Figure 1) and temperatures fluctuates (Figure 2). Here Coronal mass ejections (CMEs) are the most important solar events with important energy dissipated in interplanetary medium modifying atmospheric circulation and chemistry (overpressure or depression).…”

“…Referring ourselves to previous works on solar and geomagnetic activities done by Lockwood et al [11] and by Zerbo et al [8], where it is showed that the interplanetary magnetic field (IMF) has doubled his intensity during this last century and that solar activity shows important gradual augmentation, we can presume the fact a link exists between solar activity and temperature variations as suggested by J. E. Solheim et al [12]. Figure 3 superimposes sunspot numbers and polar cap index (PCI).…”

“…These periods are characterized by high stream solar wind speed flowing from coronal holes [6][7][8] most disturbed magnetic field with important solar dynamo and joule effect. All that implies that there is no zero climate response to the non constant energy receive from sun (G. Tsiropoula [13]).…”

“…This heat radiation from the Sun is believed to be the primary factor of Earth climate conditions. Several studies have been made over the last decade on geomagnetic activities and weather variations (Delouis and Mayaud [1], Courtillot and Le Mouel [2]; Legrand and Simon [3], Simon and Legrand [4], Gonzalez et al [5], Ouattara et al [6], Zerbo et al [7,8]) and local magnetic observations (Patel. [9], Courtillot and Le Mouel [10]).…”

United Nations Basic Space Science Initiative (UNBSSI) 1991-2012 and Beyond

“…Kazakhstan (1) CALLISTO (1) 54. Kenya (8) CALLISTO (1), GPS_Africa(1), MAGDAS(1), SCINDA (2), SID(3) 55. Korea (2) SID (2) 56.…”