THE RELATION OF CA-II K FEATURES TO MAGNETIC-FIELD

We studied quantitatively the relation between the intensity of Call K -line bright features and the intensity of the associated magnetic ele ments using two data sets obtained at the Big Bear Solar Observatory. Both network and intranetwork (IN) structures were considered. Magneti c held changes always affected the K-line emission; for example, the a ppearance of new bipoles was always followed by enhanced K-line emissi on. There is an almost linear correlation between the K-line intensity and the magnetic field strength of the stronger network elements (ele ments with absolute field strength higher than 11-19.5 G). We identifi ed two classes of intranetwork K-line elements: magnetic and non-magne tic ones. The number of the magnetic K-line IN elements above a I-sigm a threshold was only 5%-10% of the number of the non-magnetic ones. Th e magnetic K-line IN elements were almost 3 to 4 times brighter compar ed to the non-magnetic elements. On the other hand, the non-magnetic e lements were moving with typical velocities of 35-40 km s(-1) while th e velocities of the magnetic K-line elements were of the order of 1 km s(-1).