In the present work we introduce a new flare activity indicator, MAD and examine its characteristics by analyzing a set of successive three days' observations of a typical active region, AR2372. The computed MAD is compared with conventional activity indicator such as separator. It is found that. (1) MAD traces very well the separator, (2) it. singles out. local discontinuity of magnetic field lines and (3) it. is a good measure of describing the evolutionary status of active region.

• Y-J. MOON(Korea Astronomy Observatory/Department of Astronomy, Seoul National University)
• H. S. YUN(Department of Astronomy, Seoul National University)
• Y. D. PARK(Korea Astronomy Observatory)