Spectral method of global minimum (MGM) and its application to problems of heliospheric and planetary physics

Time changes of solar activity, interplanetary magnetic field and solar wind velocity at the Earth's orbit in different spectral bands

“…The period of 26.7 d can then be interpreted as period of relative rotation of sunspots at mean latitude of their appearance j ¼ 15 with T 1 ¼ 25:28 d, combined with the rotation of the Sun at the base of convection zone, with T ¼ 1:3 yr at the same latitudes (Howe et al, 2000). Taking T 2 ¼ 1:3 yr ¼ 474:81 d and 1=T 12 ¼ 1=T 1 AE 1=T 2 , where alternative signs apply because rotation at T ¼ 1:3 yr occurs in opposite phase below and above the base of the convection zone (Howe et al, 2000), we obtain T 12 ¼ 26:7 or 24.0 d. We have previously found evidence that the 24 d period exists in IMF data measured in the solar wind near the Mars on board Phobos-2 (Kuznetsova et al, 1995;Tsirulnik et al, 1997a).…”

“…A description of the method by which the statistical significance of spectral components is estimated can be found in Tsirulnik et al (1997b). A complete description of MGM can be found in Kuznetsova et al (1995) and Tsirulnik et al (1997a). We used series of 27-day averaged jBj values of the IMF based on hourly mean values measured by various spacecrafts in the solar wind near the plane of the ecliptic at a distance of 1 AU during the time period 1964-1997 obtained from the OMNI database (http://www.omni.web.gsfc.nasa.…”

Solar cycles in global temperatures

“…MGM is capable of making a self-consistent selection of trends (polynomials or sinusoids) from a data set and singling out non-stationary sinusoids (with varying phase and amplitude). MGM and technique of removing a white noise from original time series is described by Tsirulnik et al 1997. We use data of annual sunspot numbers W for 1700 -2003; annual anomalies of Global Temperature (GT) for the period 1000 -1990 obtained from proxy data (Jones et al 1998).…”