Chromospheric Ejections Associated with Type III Radio-Bursts

We study the dynamics of an IIα absorbing structure associated with a type III radioburst. We use a “Differential Cloud Model” to analyse the observed line profiles, in order to determine radial velocity and microturbulence (or shear) as functions of time.We assume that the material is flowing inside magnetic flux tubes, with a given velocity distribution. We analyse the motions in a phase-diagram (position x,velocity V). The evolution of velocity and microturbulcnce is compared to the observations. The model accounts qualitatively for the evolution of velocity, and qualitatively for the decrease of microturbulence.