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A recent study demonstrated that freedom of convection and strength of magnetic field in the photospheric feet of active-region (AR) coronal loops, together, can engender or quench heating in them. Other studies stress that magnetic flux cancellation at the loop-feet potentially drives heating in loops. We follow 24-hour movies of a bipolar AR, using EUV images from SDO/AIA and line-of-sight (LOS) magnetograms from SDO/HMI, to examine magnetic polarities at the feet of 23 of the brightest coronal loops. We derived FeXVIII emission (hot-94) images (using the Warren et al. method) to select the hottest/brightest loops, and confirm their footpoint locations via non-force-free field extrapolations. From 6$times$6 boxes centered at each loop foot in LOS magnetograms we find that $sim$40% of the loops have both feet in unipolar flux, and $sim$60% of the loops have at least one foot in mixed-polarity flux. The loops with both feet unipolar are $sim$15% shorter lived on average than the loops having mixed-polarity foot-point flux, but their peak-intensity averages are equal. The presence of mixed-polarity magnetic flux in at least one foot of majority of the loops suggests that flux cancellation at the footpoints may drive most of the heating. But, the absence of mixed-polarity magnetic flux (to the detection limit of HMI) in $sim$40% of the loops suggests that flux cancellation may not be necessary to drive heating in coronal loops -- magnetoconvection and field strength at both loop feet possibly drive much of the heating, even in the cases where a loop foot presents mixed-polarity magnetic flux.
Surprisingly few solar coronal loops have been observed simultaneously with TRACE and SOHO/CDS, and even fewer analyses of these loops have been conducted and published. The SOHO Joint Observing Program 146 was designed in part to provide the simulta
Here we report on the unique observation of flaring coronal loops at the solar limb using high resolution imaging spectropolarimetry from the Swedish 1-meter Solar Telescope. The vantage position, orientation and nature of the chromospheric material
Employing Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) multi-wavelength images, we report the coronal condensation during the magnetic reconnection (MR) between a system of open and closed coronal loops. Higher-lying magnetical
There is evidence for coronal plasma flows to break down into fragments and to be laminar. We investigate this effect by modeling flows confined along magnetic channels. We consider a full MHD model of a solar atmosphere box with a dipole magnetic fi
A joint campaign of various space-borne and ground-based observatories, comprising the Japanese Hinode mission (HOP~338, 20,--,30~September 2017), the GREGOR solar telescope, and the textit{Vacuum Tower Telescope} (VTT), investigated numerous targets