TY - JOUR
T1 - Change of sunspot groups observed from 2002 to 2011 at butterstar observatory
AU - Sung-Jin, Oh
AU - Heon-Young, Chang
PY - 2012/9
Y1 - 2012/9
N2 - Since the development of surface magnetic features should reflect the evolution of the solar magnetic field in the deep interior of the Sun, it is crucial to study properties of sunspots and sunspot groups to understand the physical processes working below the solar surface. Here, using the data set of sunspot groups observed at the ButterStar observatory for 3,364 days from 2002 October 16 to 2011 December 31, we investigate temporal change of sunspot groups depending on their Zürich classification type. Our main findings are as follows: (1) There are more sunspot groups in the southern hemisphere in solar cycle 23, while more sunspot groups appear in the northern hemisphere in solar cycle 24. We also note that in the declining phase of solar cycle 23 the decreasing tendency is apparently steeper in the solar northern hemisphere than in the solar southern hemisphere. (2) Some of sunspot group types make a secondary peak in the distribution between the solar maximum and the solar minimum. More importantly, in this particular data set, sunspot groups which have appeared in the solar southern hemisphere make a secondary peak 1 year after a secondary peak occurs in the solar northern hemisphere. (3) The temporal variations of small and large sunspot group numbers are disparate. That is, the number of large sunspot group declines earlier and faster and that the number of small sunspot group begins torise earlier and faster. (4) The total number of observed sunspot is found to behave morelikewise as the small sunspot group does. Hence, according to our findings, behaviors andevolution of small magnetic flux tubes and large magnetic flux tubes seem to be differentover solar cycles. Finally, we conclude by briefly pointing out its implication on the space weather forecast.
AB - Since the development of surface magnetic features should reflect the evolution of the solar magnetic field in the deep interior of the Sun, it is crucial to study properties of sunspots and sunspot groups to understand the physical processes working below the solar surface. Here, using the data set of sunspot groups observed at the ButterStar observatory for 3,364 days from 2002 October 16 to 2011 December 31, we investigate temporal change of sunspot groups depending on their Zürich classification type. Our main findings are as follows: (1) There are more sunspot groups in the southern hemisphere in solar cycle 23, while more sunspot groups appear in the northern hemisphere in solar cycle 24. We also note that in the declining phase of solar cycle 23 the decreasing tendency is apparently steeper in the solar northern hemisphere than in the solar southern hemisphere. (2) Some of sunspot group types make a secondary peak in the distribution between the solar maximum and the solar minimum. More importantly, in this particular data set, sunspot groups which have appeared in the solar southern hemisphere make a secondary peak 1 year after a secondary peak occurs in the solar northern hemisphere. (3) The temporal variations of small and large sunspot group numbers are disparate. That is, the number of large sunspot group declines earlier and faster and that the number of small sunspot group begins torise earlier and faster. (4) The total number of observed sunspot is found to behave morelikewise as the small sunspot group does. Hence, according to our findings, behaviors andevolution of small magnetic flux tubes and large magnetic flux tubes seem to be differentover solar cycles. Finally, we conclude by briefly pointing out its implication on the space weather forecast.
KW - Data analysis.
KW - Sun
KW - Sunspot groups
UR - http://www.scopus.com/inward/record.url?scp=84870261741&partnerID=8YFLogxK
U2 - 10.5140/JASS.2012.29.3.245
DO - 10.5140/JASS.2012.29.3.245
M3 - Article
AN - SCOPUS:84870261741
SN - 2093-5587
VL - 29
SP - 245
EP - 251
JO - Journal of Astronomy and Space Sciences
JF - Journal of Astronomy and Space Sciences
IS - 3
ER -