Sunspot waves and triggering of homologous active region jets

Abstract

We present and discuss multiwavelength observations of five homologous recurrent solar jets that occurred in active region NOAA 11133 on 2010 December 11. These jets were well observed by the Solar Dynamic observatory (SDO) with high spatial and temporal resolution. The speed of the jets ranged between 86 and 267 km s−1. A type III radio burst was observed in association with all the five jets. The investigation of the overall evolution of magnetic field in the source regions suggested that the flux was continuously emerging on longer term. However, all the jets but J5 were triggered during a local dip in the magnetic flux, suggesting the launch of the jets during localized submergence of magnetic flux. Additionally, using the PFSS modelling of the photospheric magnetic field, we found that all the jets were ejected in the direction of open field lines. We also traced sunspot oscillations from the sunspot interior to foot-point of jets and found presence of ∼3 min oscillations in all the SDO/AIA (Atmospheric Imaging Assembly) passbands. The wavelet analysis revealed an increase in amplitude of the oscillations just before the trigger of the jets, that decreased after the jets were triggered. The observations of increased amplitude of the oscillation and its subsequent decrease provides evidence of wave-induced reconnection triggering the jets.