Latitudinal migration of sunspots based on the ESAI database

作     者：Juan Zhang Fu-Yu Li Wen Feng 

作者机构：Yunnan Observatories Chinese Academy of Sciences Kunming 650011 China Research Center of Analysis and Measurement Kunming University of Science and Technology Kunming 650093 China University of Chinese Academy of Sciences Beijing 100049 China Key Laboratory of Solar Activity National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China State Key Laboratory of Space Weather Chinese Academy of Sciences Beijing 100190 China 

出 版 物：《Research in Astronomy and Astrophysics》 (天文和天体物理学研究（英文版）)

年 卷 期：2018年第18卷第1期

页      面：83-94页

核心收录：

学科分类：090801[农学-水产养殖] 0709[理学-地质学] 0908[农学-水产] 07[理学] 09[农学] 0708[理学-地球物理学] 070401[理学-天体物理] 0704[理学-天文学] 0825[工学-航空宇航科学与技术] 

基　　金：supported by the National Natural Science Foundation of China(11573065 and 11633008) the Specialized Research Fund for State Key Laboratories and the Chinese Academy of Sciences 

主　　题：Sun：activity Sun：general Sun：sunspots methods：data analysis 

摘      要：The latitudinal migration of sunspots toward the equator,which implies there is propagation of the toroidal magnetic flux wave at the base of the solar convection zone,is one of the crucial observational bases for the solar dynamo to generate a magnetic field by shearing of the pre-existing poloidal magnetic field through differential rotation.The Extended time series of Solar Activity Indices（ESAI）elongated the Greenwich observation record of sunspots by several decades in the past.In this study,ESAI＇s yearly mean latitude of sunspots in the northern and southern hemispheres during the years 1854 to 1985 is utilized to statistically test whether hemispherical latitudinal migration of sunspots in a solar cycle is linear or nonlinear.It is found that a quadratic function is statistically significantly better at describing hemispherical latitudinal migration of sunspots in a solar cycle than a linear function.In addition,the latitude migration velocity of sunspots in a solar cycle decreases as the cycle progresses,providing a particular constraint for solar dynamo models.Indeed,the butterfly wing pattern with a faster latitudinal migration rate should present stronger solar activity with a shorter cycle period,and it is located at higher latitudinal position,giving evidence to support the Babcock-Leighton dynamo mechanism.