TRANSITIONS FROM METASTABLE LEVELS EMITTED DURING SHORT-DURATION BURSTS - HOW VALID ARE THEIR CALCULATED INTENSITIES

Recent spectroscopic studies of the quiescent and transient phenomena that take place in the Sun's atmosphere suggest that short-duration bursts may play a significant role in the heating processes of the upper solar atmosphere. Accepting bursts as working processes, concepts of electron density diagnostics in the upper solar atmosphere, and element abundance determinations, methods which are based mostly on line ratios formed in steady state coronal equilibrium are being reexamined. A review of the Fe IX density diagnostics and the effects of high-temperature short-lived bursts on this unique atomic system is given. An account of some of the metastable emission lines used in solar plasma diagnostics, and the electron densities at which they may become affected as a result of short-lived bursts, is also given.