Modelling explosive events in the solar atmosphere

High-resolution ultraviolet (UV) spectra of the outer solar atmosphere show transient brightenings often referred to as explosive events. These are lo calized regions of small spatial extent that show sudden enhancements in th e intensities of lines formed between 20,000 and 200,000 K, accompanied by strong non-gaussian profiles. The present work is an attempt to extract observational consequences from c omputational simulations of the dynamic response of a coronal loop to energ y perturbations. Explosive events are simulated in semi-circular magnetic f lux tubes. Thermal energy perturbations drive flows along the flux tube giv ing rise to thermodynamic phenomena. The temporal evolution of the thermody namic state of the loop is converted into C IV lambda 1538.2 Angstrom line profiles in (non)-equilibrium ionization, Time dependent carbon ion populat ions are obtained in the nonequilibrium conditions derived from the thermod ynamic variables by means of an adaptive grid code. Most important, departu res from ionization equilibrium are assessed for the first time under condi tions such as those encountered in explosive events.