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SUMMARY:The role of the chromospheric canopy in the formation of a penumbr
 a
DTSTART;VALUE=DATE-TIME:20230509T131000Z
DTEND;VALUE=DATE-TIME:20230509T132500Z
DTSTAMP;VALUE=DATE-TIME:20240704T115653Z
UID:indico-contribution-312@meetings.aip.de
DESCRIPTION:Speakers: Philip Lindner (Leibniz-Institut fuer Sonnenphysik (
 KIS))\nWhile it is being conjectured that a chromospheric canopy plays a r
 ole in penumbra formation\, it has been difficult to find observational ev
 idence of the connectivity between the photosphere and the chromosphere. \
 n\nWe investigate the existence of a chromospheric canopy as a necessary c
 ondition for the formation of a penumbra and aim to find the origin of the
  inclined magnetic fields. Spectropolarimetric observations of NOAA AR 127
 76 from the GRIS@GREGOR instrument were analyzed. Atmospheric parameters w
 ere obtained from the deep photospheric Ca I 10839 Å line (VFISV inversio
 n code)\, the mostly photospheric Si I 10827 Å line (SIR inversion code) 
 and the chromospheric He I 10830 Å triplet (HAZEL inversion code). \n\nIn
  the deepest atmospheric layers\, we find that the magnetic properties (in
 clination and field strength distribution) measured on the sunspot sector 
 with fully fledged penumbra are similar to those measured on the sector wi
 thout penumbra. Yet\, in higher layers\, magnetic properties are different
 . In the region showing no penumbra\, almost vertical chromospheric magnet
 ic fields are observed. Additionally\, thin filamentary structures with a 
 maximum width of 0.1 arcsec are seen in photospheric high-resolution TiO-b
 and images in this region. \n\nThe existence of a penumbra is found to be 
 discriminated by the conditions in the chromosphere. This indicates that a
  chromospheric canopy is a necessary condition for the formation of a penu
 mbra. However\, our results demonstrate that inclined fields in the chromo
 spheric canopy are not needed for the development of inclined fields in th
 e photosphere. We question the `fallen-magnetic-flux-tubes' penumbra forma
 tion scenario and favor a scenario\, in which inclined fields emerge from 
 below the surface and are blocked by the overlying chromospheric canopy.\n
 \nhttps://meetings.aip.de/event/24/contributions/312/
LOCATION:Haus H\, Telegrafenberg
URL:https://meetings.aip.de/event/24/contributions/312/
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