Photospheric magnetic field of the Sun: two patterns of the longitudinal distribution

Longitudinal distributions of the photospheric magnetic field studied on the base of National Solar Observatory (Kitt Peak) data (1976 - 2003) displayed two opposite patterns during different parts of the 11-year solar cycle. Heliolongitudinal distributions differed for the ascending phase and the maximum of the solar cycle on one hand, and for the descending phase and the minimum on the other, depicting maxima around two opposite Carrington longitudes (180 deg. and 0/360 deg.). Thus the maximum of the distribution shifted its position by 180 deg. with the transition from one characteristic period to the other. Two characteristic periods correspond to different situations occurring in the 22-year magnetic cycle of the Sun, in the course of which both global magnetic field and the magnetic field of the leading sunspot in a group change their sign. During the ascending phase and the maximum (active longitude 180 deg.) polarities of the global magnetic field and those of the leading sunspots coincide, whereas for the descending phase and the minimum (active longitude 0/360 deg.) the polarities are opposite. Thus the observed change of active longitudes may be connected with the polarity changes of Sun's magnetic field in the course of 22-year magnetic cycle

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

RISK FACTORS IN PATIENTS WITH CARDIOVASCULAR DISEASES

Introduction: Cardiovascular diseases (CVD) are a socially significant problem and are theleading cause of death worldwide. A number of studies prove that lifestyle changes related to weightreduction, active physical activity, control of arterial hypertension can delay and possibly prevent thedevelopment of CVD.Objective: To investigate the presence of risk factors in patients with cardiovascular diseases.179Material and methods: Analysis of literary sources, documentary and survey method (directindividual anonymous survey) are applied. The opinion of 54 patients treated at "Sveta Marina" UMBALEAD - Varna - Department of Invasive Cardiology and Department of Non-Invasive Cardiology at theSecond Clinic of Cardiology was studied. The research was conducted in the period April - May 2022.Graphical analysis was applied to visualize the observed processes and phenomena. The Microsoft OfficeExcel software package was used to create the graphs.Results and discussion: The results of the study prove the presence of family burden in themajority of patients. A significant part of the respondents answered that they do not follow a dietaryregime with restriction of cooking salt and do not consume fruits and vegetables daily. The majority ofrespondents indicate that they do not have daily physical activity. Two-thirds of the study participantshad been under stress in the past year and the same number were smokers.Conclusion: The study of the presence of risk factors in patients with cardiovascular diseases isan important prerequisite for active work in the direction of overcoming them. Nurses can significantlycontribute in this direction, through prophylactic activities for the prevention of cardiovascular diseases

Hemispheric Sunspot Numbers R_n and R_s: Catalogue and N-S asymmetry analysis

Sunspot drawings are provided on a regular basis at the Kanzelhoehe Solar Observatory, Austria, and the derived relative sunspot numbers are reported to the Sunspot Index Data Center in Brussels. From the daily sunspot drawings, we derived the northern, R_n, and southern, R_s, relative sunspot numbers for the time span 1975-2000. In order to accord with the International Sunspot Numbers R_i, the R_n and R_s have been normalized to the R_i, which ensures that the relation R_n + R_s = R_i is fulfilled. For validation, the derived R_n and R_s are compared to the international northern and southern relative sunspot numbers, which are available from 1992. The regression analysis performed for the period 1992-2000 reveals good agreement with the International hemispheric Sunspot Numbers. The monthly mean and the smoothed monthly mean hemispheric Sunspot Numbers are compiled into a catalogue. Based on the derived hemispheric Sunspot Numbers, we study the significance of N-S asymmetries and the rotational behavior separately for both hemispheres. We obtain that about 60% of the monthly N-S asymmetries are significant at a 95% level, whereas the relative contributions of the northern and southern hemisphere are different for different cycles. From the analysis of power spectra and autocorrelation functions, we derive a rigid rotation with about 27 days for the northern hemisphere, which can be followed for up to 15 periods. Contrary to that, the southern hemisphere reveals a dominant period of about 28 days, whereas the autocorrelation is strongly attenuated after 3 periods. These findings suggest that the activity of the northern hemisphere is dominated by an active zone, whereas the southern activity is mainly dominated by individual long-lived sunspot groups.Comment: 9 pages, 8 figures, data catalogue online available at http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/390/70

Ripples and Rush-to-the-Poles in the photospheric magnetic field

The distribution of magnetic fields of positive and negative polarities over the surface of the Sun was studied on the basis of synoptic maps NSO Kitt Peak (1978-2016). To emphasize the contribution of weak fields the following transformation of synoptic maps was made: for each synoptic map only magnetic fields with modulus less than 5 G (|B| < 5 G) were left unchanged on each synoptic map while larger or smaller fields were replaced by the corresponding limiting values +5 G or -5 G. Cyclic variations of the magnetic field polarity have been observed associated with two types of magnetic field flows in the photosphere. Rush-to-the-Poles (RTTP) form near the maximum of solar activity and have the same sign as the following sunspots. The lifetime of RTTP is 3 yrs, during which time they drift from latitudes 30 - 40 deg. to the pole, causing the polarity change of the Sun's polar field. We studied another type of variations which has the form of series of flows with individual flows of 0.5-1 yr and with alternating polarity (ripples). Ripples are located in time between two RTTP and drift from the equator to the latitudes of 50 deg. Magnetic field variations were considered in 6 time intervals along the latitudes +33 deg. in the northern and -33 deg. in the southern hemispheres. The time change of the field strength was approximated by the sinusoidal function. The period of variation of ripples was 1.1 yr for the N-hemisphere and 1.3 yr for the S-hemisphere. The amplitude of variation was higher for the time intervals where the polar field had a positive sign. Within the same flow, fields of positive and negative signs developed in anti-phase.Comment: 15 pages, 12 figure