Property of emerging flux regions and corresponding response of the upper atmosphere

Abstract

Using data from the Helioseismic and Magnetic Imager and the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory, we study the property of emerging flux regions and the response of upper solar atmosphere to the flux emergence. Property of the EFRs is delineated by the total emerged flux, flux growth rate, the maximum area, the duration of the emergence and the separation speed of the opposite polarities. The response of the upper atmosphere is addressed by the response of the atmosphere at different wavelengths (and thus at different temperatures). The total emerged fluxes are in the range of (0.48−11.2) × 10¹⁹Mx while the maximum area ranges from 17 to 182 arcsec². The durations of the emergence are between 1 and 12 hours and positively correlated to both the total emerged flux and the maximum area. The maximum distances between the opposite polarities are 7−25 arcsec and the separation speeds are from 0.05 to 1.08 km s^-1, negatively correlated to the duration. The derived flux growth rates are (0.1−1.1)  × 10¹⁹Mx/hr, which are positively correlated to the total emerging flux. The upper atmosphere responds to the flux emergence in the 1600 Å chromospheric line first, and then tens and hundreds of seconds later, in coronal lines, such as the 171 Å (T = 10^5.8K) and 211 Å (T = 10^6.3K) lines almost simultaneously, suggesting the successively heating of atmosphere from the chromosphere to the corona.