Slow magnetoacoustic gravity waves in an equilibrium stratified solar atmosphere: cut-off periods through the transition region

COSTA, A; SCHNEITER, M; ZURBRIGGEN, E

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2018

0035-8711

ssuming the thin flux tube approximation, we introduce an analyticalmodel that contemplates the presence of: a non-isothermal temperature; avarying magnetic field and a non-uniform stratified medium inhydrostatic equilibrium due to a constant gravity acceleration. Thisallows the study of slow magnetoacoustic cut-off periods across thesolar transition region, from the base of the solar chromosphere to thelower corona. The used temperature profile approaches the VAC solaratmospheric model. The periods obtained are consistent withobservations. Similar to the acoustic cut-off periods, the resultingmagnetoacoustic gravity ones follow the sharp temperature profile, butshifted towards larger heights; in other words, at a given height themagnetoacoustic cut-off period is significantly lower than thecorresponding acoustic one. Along a given longitude of an inclined thinmagnetic tube, the greater its inclination the softener the temperaturegradient it crosses. Changes in the magnetic field inte