Solar flares with long soft X-ray decays: Energy balance in giant loops

Solar flares with long X-ray decays (Long-Decay Flars, LDF) are studied. X- ray and radio observations can be used to trace the active phase of an LDF and the subsequent development of a system of giant coronal loops. The ener gy balance in a giant loop is modeled for the events of January 24, 1992 (a n elementary LDF, considered earlier), November 2, 1991, and March 15, 1993 ; the modeling shows that energy flow into the loop over the entire life ti me of the LDF is necessary to account for the duration of the events. The t otal energy of the LDF was confined within rather narrow limits and was com parable to the energy of major impulsive flares. The results are consistent with the concept (developed in connection with Yohkoh observations) that a n LDF in a posteruptive process results in magnetic reconnection in a verti cal current sheet, with the subsequent formation of new loops and their spe cific evolution. (C) 2000 MAIK "Nauka/Interperiodica".