A QUANTITATIVE-ANALYSIS OF THE SURGE OF MARCH 19, 1989

A large surge event appearing in AR 5395 was observed at the Yunnan Ob servatory on March 19, 1989. H alpha spectral profiles of the event ar e interpreted by using a two-cloud model and the contours of three par ameters: excitation temperature, T-exc, microturbulent velocity, V-t, and column density of hydrogen atoms at the second level, N-0,N-2, are obtained, respectively. The question about the unique feature of the solution obtained by the fitting method is also discussed. The results show that the surge is composed of some conglomerated materials with higher temperature and density; the mass ejection is probably intermit tent. Neither T-exc, nor N-0,N-2 vary with the height over the solar l imb but decrease from the center to the periphery of the surge. V-t va ries from 10 to 30 km s(-1) and decreases with height. Some other impo rtant parameters, such as electron density, n(e), and electron pressur e, P-e, etc., have also been estimated. In the surge, with N-0,N-2 abo ut 2.0 x 10(12) cm(-2) and T-exc about 8500 K on average, we obtained n(e) = 1.80 x 10(10) cm(-3) and P-e = 0.023 dyn cm(-2). The energy var iations of the surge during the ascending phase are estimated.