Luc Rouppe van der Voort

In recent years, various chromospheric jet-like phenomena have been discovered in sunspots. There are impulsive penumbral and umbral microjets and slower, longer-lived, and more ubiquitous sunspot dynamic fibrils. Furthermore, surges and jest observed above sunspots light bridges. There have been strong indications that magnetic reconnection is the driving mechanism of the impulsive type of these phenomena. The more regular and cyclic occurring type of jets are attributed to magneto-acoustic waves leaking into the higher atmosphere. Comprehensive studies demonstrate the need for further multi-height investigation of the magnetic and dynamic structure through the photosphere and chromosphere, in order to identify heating mechanisms and the height at which energy is deposited. EST will be optimised for this type of analyses as it will provide simultaneously high spatial and temporal resolution observations of multiple spectral lines sampling different layers of the solar photosphere and chromosphere. Combined with high-sensitivity spectro-polarimetry, we will be able to fully characterise the different types of jets in sunspots and address their formation mechanisms.