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Title: MERIDIONAL CIRCULATION IN THE SOLAR CONVECTION ZONE: TIME–DISTANCE HELIOSEISMIC INFERENCES FROM FOUR YEARS OF HMI/SDO OBSERVATIONS

Abstract

We present and discuss results from time–distance helioseismic measurements of meridional circulation (MC) in the solar convection zone using 4 yr of Doppler velocity observations by the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory. Using a built-in mass conservation constraint in terms of the stream function, we invert helioseismic travel times to infer the MC in the solar convection zone. We find that the return flow that closes the MC is possibly beneath the depth of 0.77 R{sub ⊙}. We discuss the significance of this result in relation to other helioseismic inferences published recently and possible reasons for the differences in the results. Our results show clearly the pitfalls involved in the measurements of material flows in the deep solar interior given the current limits on the signal-to-noise ratio and our limited understanding of systematics in the data. We also discuss the implications of our results for the dynamics of solar interior and popular solar dynamo models.

Authors:
 [1]
  1. Indian Institute of Astrophysics, Koramangala II Block, Bangalore (India)
Publication Date:
OSTI Identifier:
22521931
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 813; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CONVECTION; DISTANCE; OSCILLATIONS; SEISMICITY; SIGNAL-TO-NOISE RATIO; STAR MODELS; STREAMS; SUN; VELOCITY; ZONES

Citation Formats

Rajaguru, S. P., and Antia, H. M., E-mail: rajaguru@iiap.res.in. MERIDIONAL CIRCULATION IN THE SOLAR CONVECTION ZONE: TIME–DISTANCE HELIOSEISMIC INFERENCES FROM FOUR YEARS OF HMI/SDO OBSERVATIONS. United States: N. p., 2015. Web. doi:10.1088/0004-637X/813/2/114.
Rajaguru, S. P., & Antia, H. M., E-mail: rajaguru@iiap.res.in. MERIDIONAL CIRCULATION IN THE SOLAR CONVECTION ZONE: TIME–DISTANCE HELIOSEISMIC INFERENCES FROM FOUR YEARS OF HMI/SDO OBSERVATIONS. United States. https://doi.org/10.1088/0004-637X/813/2/114
Rajaguru, S. P., and Antia, H. M., E-mail: rajaguru@iiap.res.in. 2015. "MERIDIONAL CIRCULATION IN THE SOLAR CONVECTION ZONE: TIME–DISTANCE HELIOSEISMIC INFERENCES FROM FOUR YEARS OF HMI/SDO OBSERVATIONS". United States. https://doi.org/10.1088/0004-637X/813/2/114.
@article{osti_22521931,
title = {MERIDIONAL CIRCULATION IN THE SOLAR CONVECTION ZONE: TIME–DISTANCE HELIOSEISMIC INFERENCES FROM FOUR YEARS OF HMI/SDO OBSERVATIONS},
author = {Rajaguru, S. P. and Antia, H. M., E-mail: rajaguru@iiap.res.in},
abstractNote = {We present and discuss results from time–distance helioseismic measurements of meridional circulation (MC) in the solar convection zone using 4 yr of Doppler velocity observations by the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory. Using a built-in mass conservation constraint in terms of the stream function, we invert helioseismic travel times to infer the MC in the solar convection zone. We find that the return flow that closes the MC is possibly beneath the depth of 0.77 R{sub ⊙}. We discuss the significance of this result in relation to other helioseismic inferences published recently and possible reasons for the differences in the results. Our results show clearly the pitfalls involved in the measurements of material flows in the deep solar interior given the current limits on the signal-to-noise ratio and our limited understanding of systematics in the data. We also discuss the implications of our results for the dynamics of solar interior and popular solar dynamo models.},
doi = {10.1088/0004-637X/813/2/114},
url = {https://www.osti.gov/biblio/22521931}, journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 813,
place = {United States},
year = {Tue Nov 10 00:00:00 EST 2015},
month = {Tue Nov 10 00:00:00 EST 2015}
}