Effect of Solar Magnetic Field (SMF) on Solar Radio Flux

Effect of solar Magnetic Field (SMF) on solar piano tuner receiver Flux authorship published in the proceedings of Conference on Recent Trends of look for in Physics (CRTRP 2012) Page no. 85-91, 2012, ISBN 97881904362983.1. IntroductionThe solar use appears to be straightforwardly associated with the strong and complex solar charismatic subject subject area.The spacious solar charismatic subject field is a result of the f low-toned of plasma currents indoors the solarize, which impel charged protrudeicles to move roughly from one of the solarizes poles to another. The mean charismatic field is the strength of the longitudinal portion of the photospheric magnetic field averaged across nearly all the visible cerebral hemisphere of the Sun. The suns magnetic field has the remarkable property that it is not distributed uniformly, but concentrated in mix ropes which appear on the depict up of macular areas, plages and network. Hale first implant the depict of strong ma gnetic field in the macule from the Zeeman splitting (Hale 1908). Sunspots are the seats of the strong magnetic field and the field strength of a large macula discharge be as high as 3000 Gauss. Due to the strong magnetic field internal the sunspot, the convection is inhabited and the region becomes relatively cooler and therefore darker compared to its surrounding region. So sunspots can be treated as the stovepipe manifestation of the Suns magnetic field (Solanki 2003). accede 3.1.1. solar magnetic field (Image credit- http//www.nasa.gov)The variances of sunspot physical body permit well-established expirations of about 11 years (Hathaway et al.2002). The design of magnetic activity round of drinks is twice as that of sunspot oscillation, about 22 years on average (Hale et al. 1919). close to of the solar activity parameters vary consistently with the sunspot cycle. Among these parameter solar piano tuner move is one which has its own importance in Radio Astronomy a s the precise teaching about its dismission from its profligate region provides the details about the temperature, constituents, density, ionization, magnetic handle and the physical constitution of the various sources inside solar structure (Kundu, 1965).Thus to diagnose the solar standard pressure and the magnetic energy release in solar aureole, piano tuner observations serve as a powerful tool. The piano tuner conflate has its blood line from atmospheric layers high in the solar chromospheres and low in the solar corona, though the accurate level of origin is not yet richly known (Kane, 2003). Observations at contrasting receiving set frequencies provide the information about the various depths and the physical structure on the solar atmosphere.Accurate effortless(prenominal) tuner aggregatees at disparate frequencies are really useful for the pick out of solar physics of the distinguishable layers of solar atmosphere (Zieba, 2001). Many workers support per formed correlational statistics coefficiental statistics and spectral depth psychology of solar piano tuner feed variants (El-Raey and Scherrer, 1973). Watari (1996) canvass solar receiving set procession at several frequencies to investigate their irregularities, conviction variation and solar coronal activity at several(predicate) heights. Kane et al. (2001), Vats et al. (1998) and Mouradian et al. (2002) apply the solar radio liquifyes at different frequencies to ask the coronal rotation period at different heights and its differentiality as a office of the altitude. Meheta (2005) has analyse the relationship of rotation period with different phases of solar cycle.It is already evident in the literature that various absolute frequency bands in the spew starting from 245 megacycle to 15400 megacycle originate from different layers of solar atmosphere starting from lower chromospheres to upper corona as illustrated in the skirt 3.1. Thus study of radio amalga mate at different frequencies within this range provides the information about different layers of solar atmosphere.Table 3.1. distinguishable radio frequencies and their origin in solar atmosphereThe quiet Sun emission at different frequencies contains information about densities and temperatures in different layers of the solar atmosphere (Watari, 1996). It is one of the prime reasons of studying solar radio emission at different frequencies during the solarFigure 3.1.2. Monthly variation of sunspot number for the year 2009. (Image credit- http//www.greatdreams.com/solar/2009/ musculus quadriceps femoris-weather-december-2009.htm) stripped period which provides an probability to the scientific corporation to study the physical carriage of solar atmosphere. It in addition provides very useful information about the temperature and the conformity of the solar corona (Kundu, 1965). Thus the study of solar radio emission during the minimum period serves as an important tool for the study of solar corona. The current minimum of cycle 23-24 has been treated as a peculiar minimum characterized by reduced polar field strength, extremely low level of solar activity and extending for longer duration (Gopalswamy et al, 2012). Various solar indices like F10.7 cm, EUV flux, solar wind etc. behaved unusually during this minimum. Even the ionosphere also showed an anomalous behavior (Eduardo et al, 2011). The boundary between the Earths upper atmosphere and space also moved to an extraordinary low altitude (www.sciencedaily.com/releases/2008/12/081215121601.html) during the period. This fount of unusual behavior of this minimum has created the interest among the solar science community to receive a rigorous study on this period. The microwave ignitor temperature during this minimum was substantially diminished compared to the 22-23 minimum which is also consistent with the drop in solar magnetic field strength (Gopalswamy et al, 2012). Basu (2010) found the evid ence of difference of Suns internal structure during the current minimum from the minimum of previous cycle. During the minimum period, the 2800 MHz radio flux showed an anomalous behavior in its correlation with Sunspot number (Tapping, 2011). In the scope of above peculiarities of current solar minimum, it is interesting to see the variation of correlation of solar radio flux at several frequencies with sunspot number during this period.In this chapter the preliminary results regarding the study on the relation of solar radio flux and solar magnetic field parameters have been presented. Here the frequency dispersions of correlation coefficients of solar radio flux with sunspot number and solarmagnetic field have been investigated for solar minimum and maximum period. We have also make analysis of periodic variation of basal component of solar radio emissions.3.2. ObservationHere we studied the behavior of solar radio flux for the extended solar minima of solar cycle 23 (2009). F irstly, we calculated the correlation between the solar radio flux and Sunspot number which is the index number for measuring the variability of these two solar activity parameters. We have found the correlation coefficient at eight frequencies (245, 410, 610, 1415, 2695, 4995, 8800, 15400 MHz) using data from Sagamore Hills radio Solar observatories. For the calculation of correlation coefficient, we excluded the points from dataset of those radio fluxes, which are having values greater by 40% of the average flux value of a day. It has been do for neglecting sudden variation in flux collectable to several casual activities. The correlation coefficients are speckleted in figure. 3.2.13.2.2. correlation coefficient coefficient between the sunspot and radio flux Many workers (Das and Nag, 1999, Das and Nag, 1996) have shown that the frequency distribution of correlation coefficients of the solar radio flux and Sunspot numbers follows a pattern. We have calculated the correlation coefficients for solar maximum (2001) and minimum (2009) of solar cycle and found that the frequency distribution of the correlation coefficients does not show the similar pattern as has been describe in the literature. During the maximum period the correlation coefficient is highest for 1415 MHz but in minimum its highest for 2695 MHz. In literature also it has been reported that the correlation coefficient attains its maximum value at Figure 3.2.1 Frequency distribution of correlation coefficients of solar radio flux and sunspot number2695 MHz as it is very close to the 2800 MHz (Das and Nag, 1996). But during the solar maximum period the highest correlation has been found for 1415 MHz while at solar minimumperiod it is for 2695 MHz. or else that this subsequently 2695 MHz there is a decline in the correlation coefficient of high frequencies for maximum period where as for minimum period the trend isFigure 3.2.2 Frequency distribution of correlation coefficients of solar radi o flux and sunspot numbernot same as the 8800 MHz shows a correlation which is greater than for 4995 MHz.Rather than this the variation of correlation coefficient has also been chequered for different solar minimum period. Das and Nag, 1996 has already reported the correlation coefficient of the radio flux and the sunspot number for the 1975, 1986, 1996 minima. We have compared these correlation coefficients with the obtained ones for 2009 solar minimum. From the plot it can be noted that during this period the value of the correlation coefficient is very low in comparison to the value of the previous three minima.3.2.3. Correlation coefficient between the solar mean magnetic field and radio fluxLike the radio flux and sunspot number, the correlation between the radio flux and solar mean magnetic field has also been checked for this minimum period. It has been found that the values of the correlation co-efficient are very low and the there is a pattern in the variation of the frequ ency distribution of the correlation coefficients.Figure 3.2.2 Frequency distribution of correlation coefficients of solar radio flux and solar mean magnetic field3.3. DiscussionIn this chapter, the relation between the solar magnetic field and the solar radio flux has been investigated. In the foregoing analysis the correlation coefficient of radio emission and sunspot number, has been found to be low with respect to the correlations of other cycles. Where as the correlation of solar mean magnetic field and radio flux is also very low.During this minima period, the frequency distribution of correlation coefficient of radio flux and sunspot number and the periodic behavior of solar radio flux is haphazard whether it has a similar pattern for previous three minima (Das, 1998). The anomalousness in correlation of radio flux with sunspot number dexterity be due to the unusual behavior of the microwaves as it has been already reported for the correlation between 2800 MHz and sunspot n umber (Hudson, 2009).There was a change in activities between photospheric and chromospheric or coronal indices during the later part of cycle 23, through the extended minimum (Tapping, 2011) and the polar magnetic fields of Sun have an important role in shaping the Solar corona and heliosphere around the Solar minimum period when the polar dipole antenna moment becomes leading component of large scale magnetic field of the Sun (Wang and Sheeley, 2002).During this minima period, Suns polar field was 40% less compared to the previous three minima (Wang et al, 2009). Consistently, the corona also retained some complexness during the lowest activity level (Toma et al, 2010a). During the current minimum, the Solar corona neer reached at a simple dipolar configuration (De Toma et al, 2010b) rather the dwarf data showed higher order multi-polar structure (Judge 2010).Thus different magnetic configuration is supposed to give rise to a different geomorphology of Solar corona rather than from the previous three minima. Thus different magnetic configuration is supposed to give rise to a different morphology of Solar corona rather than from the previous three minima. The variation obtained in correlation coefficients pattern could also be due to this complex behavior of Solar corona and heliosphere.3.4. Concluding remarksThe preliminary study presented in this chapter points that during the recent solar minimum, the correlation coefficient of radio emission and sunspot number has been low with respect to the correlation coefficients of previous solar minima. Rather than this the correlation of solar mean magnetic field and radio flux is also found to be very low during this minimum period. During this minima period, the frequency distribution of correlation coefficient of radio flux and sunspot number is ergodic whether it has a similar pattern for previous three minima (Das and Nag 1998).The frequencies studied at the present work for analyzing the characteristics o f Solar radio flux, provide information about the complex behavior of Solar corona and different shape of corona with respect to the previous minima during (Toma et al, 2010b). However we believe that detail investigating with more independent analysis using different parameters is required to critically analyze different Solar features especially during the current minima period to have more insight about the physical processes going on inside the Sun at different conviction scales.ReferencesHale, G. E. 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