The formation of the Ca ii K line in a spinning spicule

The emission of the Ca ii K line from a spinning cylindrical spicule model is considered. In order to reproduce the observed spicule K line profiles, the model must have both radial and axial gradients in N _e and T _e. The rotating spicule model is optically thin at all heights and is hotter and more dense than a stationary model computed in a previous paper. It is proposed that the so-called Type I and Type II spicules may be structurally the same features, with different rotational velocities.The National Center for Atmospheric Research is sponsored by the National Science Foundation.