Multi-height Study of the Chromospheric Inverse Evershed Flow and its Association with Photospheric Flows

We analyzed the inverse Evershed flow (IEF) around a sunspot (NOAA 13131) using line scan observations in the Fe i 6173 Å and Ca ii 8542 Å spectral lines, complemented with data products from the Solar Dynamics Observatory's Helioseismic and Magnetic Imager. Line-of-sight (LOS) velocities were...

Full description

Saved in:
Bibliographic Details
Main Authors: Sandeep K. Dubey, Shibu K. Mathew, Christian Beck, Debi P. Choudhary
Format: Article
Language:English
Published: IOP Publishing 2025-01-01
Series:The Astrophysical Journal
Subjects:
Online Access:https://doi.org/10.3847/1538-4357/adc1cd
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850034192747855872
author Sandeep K. Dubey
Shibu K. Mathew
Christian Beck
Debi P. Choudhary
author_facet Sandeep K. Dubey
Shibu K. Mathew
Christian Beck
Debi P. Choudhary
author_sort Sandeep K. Dubey
collection DOAJ
description We analyzed the inverse Evershed flow (IEF) around a sunspot (NOAA 13131) using line scan observations in the Fe i 6173 Å and Ca ii 8542 Å spectral lines, complemented with data products from the Solar Dynamics Observatory's Helioseismic and Magnetic Imager. Line-of-sight (LOS) velocities were obtained for different bisector levels in both spectral lines. Additionally, the Ca ii 8542 Å spectra were inverted using the Non-LTE Inversion COde using the Lorien Engine (or NICOLE) to retrieve the temperature and velocity stratification over different layers of the lower solar atmosphere. The IEF evolved dynamically in time and with height in the solar atmosphere. The flow speed associated with the IEF channels was on the order of 8 km s ^−1 in the upper chromosphere, which decreased in the lower layers of the atmosphere. The flow was traced to the lower chromosphere in LOS velocity maps and the upper photosphere in intensity images. The temperature enhancements associated with the IEF were up to 300 K at log τ ≈ −2 and 800 K at log τ ≈ −6 near the end point of one channel. The overall appearance of the flow along the IEF channels seems consistent with a siphon flow model. We investigated the association of the IEF with the photospheric Evershed flow, but no obvious connection was found in our analysis. We also analyzed the effect of the IEF on moving magnetic features (MMF) selected near and away from IEF channels. MMFs moved radially outward with velocities in the 0.2–1 km s ^−1 range, with no apparent association with the IEF.
format Article
id doaj-art-1ba0e968f2764fdc8c81761e8f01c071
institution DOAJ
issn 1538-4357
language English
publishDate 2025-01-01
publisher IOP Publishing
record_format Article
series The Astrophysical Journal
spelling doaj-art-1ba0e968f2764fdc8c81761e8f01c0712025-08-20T02:57:55ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-01984216410.3847/1538-4357/adc1cdMulti-height Study of the Chromospheric Inverse Evershed Flow and its Association with Photospheric FlowsSandeep K. Dubey0https://orcid.org/0009-0003-5620-6163Shibu K. Mathew1https://orcid.org/0000-0002-9370-2591Christian Beck2https://orcid.org/0000-0001-7706-4158Debi P. Choudhary3https://orcid.org/0000-0002-9308-3639Udaipur Solar Observatory , Physical Research Laboratory, Udaipur, Rajasthan, 313001, India; Indian Institute of Technology , Gandhinagar, Palaj, Gujarat, 382055, IndiaUdaipur Solar Observatory , Physical Research Laboratory, Udaipur, Rajasthan, 313001, IndiaNational Solar Observatory (NSO) , 3665 Discovery Drive, Boulder, CO 80303, USADepartment of Physics and Astronomy, California State University, Northridge (CSUN) , CA 91330-8268, USAWe analyzed the inverse Evershed flow (IEF) around a sunspot (NOAA 13131) using line scan observations in the Fe i 6173 Å and Ca ii 8542 Å spectral lines, complemented with data products from the Solar Dynamics Observatory's Helioseismic and Magnetic Imager. Line-of-sight (LOS) velocities were obtained for different bisector levels in both spectral lines. Additionally, the Ca ii 8542 Å spectra were inverted using the Non-LTE Inversion COde using the Lorien Engine (or NICOLE) to retrieve the temperature and velocity stratification over different layers of the lower solar atmosphere. The IEF evolved dynamically in time and with height in the solar atmosphere. The flow speed associated with the IEF channels was on the order of 8 km s ^−1 in the upper chromosphere, which decreased in the lower layers of the atmosphere. The flow was traced to the lower chromosphere in LOS velocity maps and the upper photosphere in intensity images. The temperature enhancements associated with the IEF were up to 300 K at log τ ≈ −2 and 800 K at log τ ≈ −6 near the end point of one channel. The overall appearance of the flow along the IEF channels seems consistent with a siphon flow model. We investigated the association of the IEF with the photospheric Evershed flow, but no obvious connection was found in our analysis. We also analyzed the effect of the IEF on moving magnetic features (MMF) selected near and away from IEF channels. MMFs moved radially outward with velocities in the 0.2–1 km s ^−1 range, with no apparent association with the IEF.https://doi.org/10.3847/1538-4357/adc1cdSunspotsSunspot flowSolar chromosphereSolar photosphere
spellingShingle Sandeep K. Dubey
Shibu K. Mathew
Christian Beck
Debi P. Choudhary
Multi-height Study of the Chromospheric Inverse Evershed Flow and its Association with Photospheric Flows
The Astrophysical Journal
Sunspots
Sunspot flow
Solar chromosphere
Solar photosphere
title Multi-height Study of the Chromospheric Inverse Evershed Flow and its Association with Photospheric Flows
title_full Multi-height Study of the Chromospheric Inverse Evershed Flow and its Association with Photospheric Flows
title_fullStr Multi-height Study of the Chromospheric Inverse Evershed Flow and its Association with Photospheric Flows
title_full_unstemmed Multi-height Study of the Chromospheric Inverse Evershed Flow and its Association with Photospheric Flows
title_short Multi-height Study of the Chromospheric Inverse Evershed Flow and its Association with Photospheric Flows
title_sort multi height study of the chromospheric inverse evershed flow and its association with photospheric flows
topic Sunspots
Sunspot flow
Solar chromosphere
Solar photosphere
url https://doi.org/10.3847/1538-4357/adc1cd
work_keys_str_mv AT sandeepkdubey multiheightstudyofthechromosphericinverseevershedflowanditsassociationwithphotosphericflows
AT shibukmathew multiheightstudyofthechromosphericinverseevershedflowanditsassociationwithphotosphericflows
AT christianbeck multiheightstudyofthechromosphericinverseevershedflowanditsassociationwithphotosphericflows
AT debipchoudhary multiheightstudyofthechromosphericinverseevershedflowanditsassociationwithphotosphericflows