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dc.contributor.authorChae, Jongchulen_NZ
dc.contributor.authorKang, Juhyungen_NZ
dc.contributor.authorLitvinenko, Yuri E.en_NZ
dc.date.accessioned2020-03-15T20:54:14Z
dc.date.available2019-09-20en_NZ
dc.date.available2020-03-15T20:54:14Z
dc.date.issued2019en_NZ
dc.identifier.citationChae, J., Kang, J., & Litvinenko, Y. E. (2019). Linear acoustic waves in a nonisothermal atmosphere. II. photospheric resonator model of three-minute umbral oscillations. Astrophysical Journal, 883(1). https://doi.org/10.3847/1538-4357/ab3d2den
dc.identifier.issn0004-637Xen_NZ
dc.identifier.urihttps://hdl.handle.net/10289/13511
dc.description.abstractThe velocity oscillations observed in the chromosphere of sunspot umbrae resemble a resonance in that their power spectra are sharply peaked around a period of about three minutes. In order to describe the resonance that leads to the observed 3-minute oscillations, we propose the photospheric resonator model of acoustic waves in the solar atmosphere. The acoustic waves are driven by the motion of a piston at the lower boundary, and propagate in a nonisothermal atmosphere that consists of the lower layer (photosphere), where temperature rapidly decreases with height, and the upper layer (chromosphere), where temperature slowly increases with height. We have obtained the following results: (1) The lower layer (photosphere) acts as a leaky resonator of acoustic waves. The bottom end is established by the piston, and the top end by the reflection at the interface between the two layers. (2) The temperature minimum region partially reflects and partially transmits acoustic waves of frequencies around the acoustic cutoff frequency at the temperature minimum. (3) The resonance occurs in the photospheric layer at one frequency around this cutoff frequency. (4) The waves escaping the photospheric layer appear as upwardpropagating waves in the chromosphere. The power spectrum of the velocity oscillation observed in the chromosphere can be fairly well reproduced by this model. The photospheric resonator model was compared with the chromospheric resonator model and the propagating wave model.
dc.format.mimetypeapplication/pdf
dc.language.isoenen_NZ
dc.publisherIOP Publishing LTDen_NZ
dc.rightsThis article is published in the Astrophysical Journal. © 2019 The American Astronomical Society.
dc.subjectScience & Technologyen_NZ
dc.subjectPhysical Sciencesen_NZ
dc.subjectAstronomy & Astrophysicsen_NZ
dc.subjectmagnetohydrodynamics (MHD)en_NZ
dc.subjectwavesen_NZ
dc.subjectSun: atmosphereen_NZ
dc.subjectSun: chromosphereen_NZ
dc.subjectSun: oscillationsen_NZ
dc.subjectSun: photosphereen_NZ
dc.subjectsunspotsen_NZ
dc.subjectPHOTOELECTRIC OBSERVATIONSen_NZ
dc.subjectLOCAL OSCILLATIONSen_NZ
dc.subjectPROPAGATIONen_NZ
dc.subjectSUNSPOTSen_NZ
dc.titleLinear acoustic waves in a nonisothermal atmosphere. II. photospheric resonator model of three-minute umbral oscillationsen_NZ
dc.typeJournal Article
dc.identifier.doi10.3847/1538-4357/ab3d2den_NZ
dc.relation.isPartOfAstrophysical Journalen_NZ
pubs.elements-id241159
pubs.issue1en_NZ
pubs.publication-statusPublisheden_NZ
pubs.volume883en_NZ
dc.identifier.eissn1538-4357en_NZ
uow.identifier.article-noARTN 72


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