The Role of Magnetic Field Disturbances in the Heating of Active Region Loops

Abstract Hot emissions from coronal plasma with T > 4 MK are examined in two active regions observed by the Atmospheric Imaging Assembly (AIA) on the Solar Dynamic Observatory (SDO). The intensity maps in Fe XVIII 94 ˚A are created and the emission intensity in the brightest loops in these regions are measured. The corresponding magnetic maps of these active regions are constructed using the magnetograms from Helioseismic and Magnetic Imager onboard SDO. The photospheric magnetic field is characterized in terms of magnetic disturbances, such as flux emergence and flux cancellations in the surrounding sunspots, and the total magnetic flux is measured. The energy giving rise to high-temperature plasma is found to be deposited in the corona as a result of magnetic reconnection, likely caused by the dynamics of the magnetic field at the photosphere. The observations confirm that the hot plasma is strongly correlated with magnetic flux emergence or cancellation.