The Full-disk vector Magneto Graph(FMG)instrument will carry out polarization observations at one wavelength position of the Fe I 5324.179?spectral line.This paper describes how to choose this single wavelength positi...The Full-disk vector Magneto Graph(FMG)instrument will carry out polarization observations at one wavelength position of the Fe I 5324.179?spectral line.This paper describes how to choose this single wavelength position,the relevant data-processing and the magnetic field calibrations based on the measured polarization signals at one single wavelength position.It is found that solar radial Doppler velocity,which can cause the spectral line to shift,is a disadvantageous factor for the linear calibration at one wavelength position.Observations at two symmetric wavelength positions may significantly reduce the wavelength shift effect(~75%),but simulations show that such polarization signals located at the solar limbs(e.g.,beyond the longitude range of±30°)are not free from the effect completely.In future work,we plan to apply machine learning techniques to calibrate vector magnetic fields,or employ full Stokes parameter profile inversion techniques to obtain accurate vector magnetic fields,in order to complement the linear calibration at the single wavelength position.展开更多
Light bridges(LBs)are bright lanes that divide one sunspot umbra into two or more parts.Though frequently observed in sunspots,their formation mechanisms have rarely been studied and thus are not well understood.Here ...Light bridges(LBs)are bright lanes that divide one sunspot umbra into two or more parts.Though frequently observed in sunspots,their formation mechanisms have rarely been studied and thus are not well understood.Here we present results from the first statistical investigation on the formation of LBs.Using observations with the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory,we identified 144 LBs within 71 active regions(ARs)over the whole year of 2014.The formation processes of these LBs can be categorized into three groups:penumbral intrusion(type-A),sunspot merging(typeB)and umbral-dot emergence(type-C).The numbers of events in these three categories are 74,57 and 13,respectively.The duration of the LB formation process is mostly less than 40 hours,with an average of~20 hours.Most LBs have a maximum length of less than 20.For type-A LBs,we found a positive correlation between the LB length and the duration of the LB formation process,suggesting a similar speed of penumbral intrusion in different sunspots.展开更多
基金supported by the Strategic Priority Research Program on Space Science, the Chinese Academy of Sciences (Grant Nos. XDA15320302, XDA15052200 and XDA15320102)the National Natural Science Foundation of China (Grant Nos. 11773038, 11703042, U1731241, 11427901, 11427803, 11473039 and U1831107)the 13th Fiveyear Informatization Plan of the Chinese Academy of Sciences (Grant No. XXH13505-04)
文摘The Full-disk vector Magneto Graph(FMG)instrument will carry out polarization observations at one wavelength position of the Fe I 5324.179?spectral line.This paper describes how to choose this single wavelength position,the relevant data-processing and the magnetic field calibrations based on the measured polarization signals at one single wavelength position.It is found that solar radial Doppler velocity,which can cause the spectral line to shift,is a disadvantageous factor for the linear calibration at one wavelength position.Observations at two symmetric wavelength positions may significantly reduce the wavelength shift effect(~75%),but simulations show that such polarization signals located at the solar limbs(e.g.,beyond the longitude range of±30°)are not free from the effect completely.In future work,we plan to apply machine learning techniques to calibrate vector magnetic fields,or employ full Stokes parameter profile inversion techniques to obtain accurate vector magnetic fields,in order to complement the linear calibration at the single wavelength position.
基金supported by the National Natural Science Foundation of China(Grant Nos.11803002,11825301 and 11790304)the Strategic Priority Research Program of Chinese Academy of Sciences(XDA17040507)。
文摘Light bridges(LBs)are bright lanes that divide one sunspot umbra into two or more parts.Though frequently observed in sunspots,their formation mechanisms have rarely been studied and thus are not well understood.Here we present results from the first statistical investigation on the formation of LBs.Using observations with the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory,we identified 144 LBs within 71 active regions(ARs)over the whole year of 2014.The formation processes of these LBs can be categorized into three groups:penumbral intrusion(type-A),sunspot merging(typeB)and umbral-dot emergence(type-C).The numbers of events in these three categories are 74,57 and 13,respectively.The duration of the LB formation process is mostly less than 40 hours,with an average of~20 hours.Most LBs have a maximum length of less than 20.For type-A LBs,we found a positive correlation between the LB length and the duration of the LB formation process,suggesting a similar speed of penumbral intrusion in different sunspots.
