The 2. 7- Day Cosmic Ray Intensity Variations During Solar Minimum 2. Now that the new activity of the 2. Fortunately, measurements of solar activity and solar wind parameters are today very effectively performed by a large number of world- wide operating ground- based observatories and space probes. The values of solar activity indices in the relatively long- lasting minimum 2. The Sun was extremely quiet and had almost no sunspots on its surface (e. Smith 2. 01. 1). This unusually long and deep solar minimum has also been detected in a variety of other solar cycle indices, such as solar radio flux and total solar irradiance (e.
Orbiting Solar Observatory 2 launches into Earth orbit (552/636 km) February 4 U.S.
Fr. Simultaneously, the observations at the Wilcox Solar Observatory (WSO) reveal that the solar magnetic field is reduced across the whole surface of the Sun (Lee et al. Hoeksema 2. 00. 9). The mean value of the strength B of the interplanetary magnetic field (IMF) in the period of 2. The reason for the decrease in IMF in this minimum 2. ICMEs; Owens et al.
Namely, the maximum in power of the 27-day solar wind velocity variations (P 27 (V)) is observed A solar day is the day that we use to keep time on the planet earth. It is the time from when the sun is directly over head until the time the sun is directly over head again. This takes a rotation of about 361 degrees. YouTube Red Watch Queue Queue Watch Queue Queue Remove all Disconnect Loading. Sun Calculator Moon Calculator Moon Phases Eclipses Seasons Day and Night Map Moon Light Map Astronomy Articles Home Sun & Moon Eclipses May 30, 1965 — Total Solar Eclipse May 30. The amplitudes of the 399-day variations in solar-wind density, temperature, and speed were determined by superposed epoch analysis:~0.5cm-3~8000K, and 2.8 km.
Alternatively, Zhao and Fisk (2. The consequences of these weaker solar magnetic fields were visible in changes of the solar wind plasma flow through the interplanetary medium. Observations near the Earth orbit during the end- phase of solar cycle 2. IMF strength and solar wind density were about 3. At the same time, the Ulysses (Balogh et al. Bame et al. 1. 99.
It has been proposed that the extension of the meridional circulation and its speed determines the length of the solar cycle (Dikpati and Charbonneau 1. Dikpati (2. 01. 1) reported that the meridional circulation pattern behaved distinctly different during solar cycles. In particular, the Sun. Dikpati (2. 01. 1) furthermore noted that the highest average flow speed at the surface was the same during solar cycles 2. Altrock (2. 01. 0) showed that emission of active regions in the peculiar solar cycle 2.
These authors suggested that this difference might be a regular feature of the full . Lario and Roelof (2. In contrast to this, during the third (2. The polar coronal hole disappeared during the declining phase of cycle.
Consequently, the modulation of Galactic cosmic rays (GCR) in solar cycles. On the other hand, Zhao and Fisk (2. IMF remains valid. The GCR intensity modulation in the minimum 2. Heber et al. 2. 00. Mc. Donald, Webber, and Reames 2. Schwadron et al. 2.
Recently, Paouris et al. Therefore, the unusually weak IMF in the minimum 2. GCR intensities, which were observed by neutron monitors (e.
Moraal and Stoker 2. Mewaldt et al. 2. During solar minima, transient disturbances in the interplanetary space are infrequent and the regular IMF is well established. Therefore, it is relatively easy to distinguish the quasi- periodic variations caused by the Sun.
For the observer on the Earth the recurrence period of these variations (the synodic period) is about 2. The variations are caused by the inhomogeneous distribution of active regions on the Sun. This topic, first announced by Forbush (1. Richardson 2. 00. Generally, higher harmonics of the 2. GCR intensity variations (e. Alania and Shatashvili 1.
Particularly, the period of . This second harmonics was studied in detail, e. Mursula and Zieger (1. Recently, Sabbah and Kudela (2.
GCR time series in the period range of T< 2. The magnitude of the 2. Recently, Modzelewska and Alania (2. Gil, Modzelewska, and Alania (2.
GCR intensity variations and their dependence on the Sun. Moreover, we study their synodic quasi- periodicity as it is connected to the Sun. Based on spectral and wavelet analysis methods, we investigate the temporal variations of the synodic periodicity in the selected solar wind parameters. By combining these with the analysis of GCR intensity variations, possible evidence for the onset of the new 2.