Light Walls Around Sunspots Observed by the Interface Region Imaging   Spectrograph
  The Interface Region Imaging Spectrograph (IRIS) mission provides high-resolution observations of the chromosphere and transition region. We try to determine whether the light walls exist somewhere else in active regions besides light bridges. Employing half-year high tempo-spatial data from the IRIS, we find lots of light walls either around sunspots or above light bridges. For the first time, we report one light wall near an umbral-penumbral boundary and another along a neutral line between two small sunspots. These new observations reveal that these light walls are multi-layer and multi-thermal structures which occur along magnetic neutral lines in active regions. 
Y. J. Hou, T. Li, S. H. Yang and J. Zhang
astro-ph.SR