Speaker
Sara Esteban Pozuelo
(ISP)
Description
While the photospheric Evershed flow has been studied in-depth, the origin of its
chromospheric counterpart, the inverse Evershed effect, remains unclear. The siphon
flow mechanism has been proposed as the driver of the inverse Evershed flow, which
has been observed as a subsonic flow that becomes supersonic at the top of the
superpenumbral fibrils and then suddenly returns to subsonic velocities due to a
shock in lower layers (e.g., Maltby 1975; Beck et al. 2015). Recently, some authors
have studied the chromospheric fine-structure over sunspots to characterize their
magnetic structure (e.g., de la Cruz Rodriguez & Socas Navarro 2011; Schad et al.
2015) and noticed a mismatching between superpenumbral fibrils and the magnetic field
vector. Specifically, Schad et al. (2015) found that the magnetic field is not as
fine-structured as fibrils in intensity. We study the depth stratification of the
line-of-sight velocities derived from non-LTE inversions. We make use of a stable
temporal sequence of high spatial resolution spectropolarimetric data of a sunspot
acquired with the CRISP instrument at the Ca II 854.2 nm spectral line.
Primary author
Sara Esteban Pozuelo
(ISP)
