Publications

Vortex in observational data

Murabito, M. et al.,  Unveiling the magnetic nature of chromospheric vortices, A&A, 2020

Results: Authors present the detection of spectropolarimetric signals that manifest the magnetic nature of rotating structures in the chromosphere. Our observations show two long-lived structures of plasma that each rotate clockwise inside a 10 arcsec2 quiet-Sun region. Their circular polarisation signals are five to ten times above the noise level. Line-of-sight Doppler velocity and horizontal velocity maps from the observations reveal clear plasma flows at and around the two structures. A magnetohydrodynamics simulation shows these two structures are plausibly magnetically connected. Wave analysis suggests that the observed rotational vortex pattern could be due to a combination of slow actual rotation and a faster azimuthal phase speed pattern of a magnetoacoustic mode.

Conclusions: The results imply that the vortex structures observed in the Sun's chromosphere are magnetic in nature and that they can be connected locally through the chromosphere

Richardson, R. S. The Nature of Solar Hydrogen Vortices, ApJ, 93, 24, 1941

Antonello Provenzale, Transport by coherent barotropic vortices, Annual Review of Fluid Mechanics 31(1), 1999 DOI: 10.1146/annurev.fluid.31.1.55

Vortex identification

Vortex theory