Study On The Correlation Between Coronal Stream Activity And Solar Activity Cycles

One of the important research topics in solar physics is how the solar activity cycle modulates the formation and evolution of the solar atmospheric structure.This paper focuses on the long-term changes in the frequency and latitude of coronal extended structures(coronal streamers),and explores their relationship with the solar activity cycle.Using continuous coronal observations from SOHO/LASCO between 1998 and 2015(including a complete solar activity cycle and the transition period between solar activity cycles 23 and 24),this paper carries out the following research:(1)develops an independent 3D inversion method for coronal streamers based on a single observational instrument and applies it to continuous coronal observation data spanning 18 years;(2)statistically studies the long-term variations in the occurrence rate of coronal streamers and investigates the role of the solar activity cycle in these changes;(3)studies the long-term evolution of the latitude of coronal streamers and their correlation with the solar activity cycle.Through the above research,this paper makes the following innovative discoveries:(1)during the high solar activity years,the number of coronal streamers is significantly higher than during the low solar activity years,and the Pearson correlation coefficient between coronal streamers and sunspot numbers reaches 0.57,indicating a significant correlation between the two.The linear fitting results between the number of coronal mass ejections and sunspot numbers show a positive correlation,and the occurrence rate of coronal mass ejections is about four times that of sunspots;(2)Most coronal streamers occur near the solar equator,but highlatitude coronal streamers(up to 75 degrees)may also appear,and the frequency of high-latitude coronal streamers is higher during high solar activity years.During the high solar activity years,more high-latitude coronal streamers appear,and during the declining solar activity years,the latitude range where coronal streamers can occur shrinks towards the equator as sunspots migrate towards the equator,resulting in a time-latitude distribution of coronal streamers that exhibits similar characteristics to the Maunder butterfly diagram.During the ascending phase of the solar activity cycle,even if sunspots appear at higher latitudes,high-latitude coronal streamers are still rare.Based on the research,this paper concludes that:(1)the open field system and closed field system carried by emerging active regions jointly modulate the occurrence of coronal streamers;(2)the occurrence of coronal streamers is a result of the mutual balance between the open and closed field systems of active regions and the open field system of the solar polar regions;(3)the interaction between the open field system of active regions and the background closed field system during the latitudinal migration may be one of the important drivers for the formation of the solar wind.This paper’s research provides important references for understanding the long-term evolution of coronal streamers and also provides methodological references and data preparations for further study of the physical processes that modulate coronal streamer activity during solar activity cycles.