University of Oulu

Reconstructing solar magnetic fields from historical observations - II. Testing the surface flux transport model. I. O. I. Virtanen, I. I. Virtanen, A. A. Pevtsov, A. Yeates and K. Mursula. A&A, 604 (2017) A8. DOI:

Reconstructing solar magnetic fields from historical observations : II. Testing the surface flux transport model

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Author: Virtanen, I. O. I.1; Virtanen, I. I.1; Pevtsov, A. A.1,2;
Organizations: 1ReSoLVE Centre of Excellence, Space Climate research unit, University of Oulu
2National Solar Observatory
3Department of Mathematical Sciences, Durham University
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 4.8 MB)
Persistent link:
Language: English
Published: EDP Sciences, 2017
Publish Date: 2017-10-30


Aims: We aim to use the surface flux transport model to simulate the long-term evolution of the photospheric magnetic field from historical observations. In this work we study the accuracy of the model and its sensitivity to uncertainties in its main parameters and the input data.

Methods: We tested the model by running simulations with different values of meridional circulation and supergranular diffusion parameters, and studied how the flux distribution inside active regions and the initial magnetic field affected the simulation. We compared the results to assess how sensitive the simulation is to uncertainties in meridional circulation speed, supergranular diffusion, and input data. We also compared the simulated magnetic field with observations.

Results: We find that there is generally good agreement between simulations and observations. Although the model is not capable of replicating fine details of the magnetic field, the long-term evolution of the polar field is very similar in simulations and observations. Simulations typically yield a smoother evolution of polar fields than observations, which often include artificial variations due to observational limitations. We also find that the simulated field is fairly insensitive to uncertainties in model parameters or the input data. Due to the decay term included in the model the effects of the uncertainties are somewhat minor or temporary, lasting typically one solar cycle.

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Series: Astronomy and astrophysics
ISSN: 0004-6361
ISSN-E: 1432-0746
ISSN-L: 0004-6361
Volume: 604
Article number: A8
DOI: 10.1051/0004-6361/201730415
Type of Publication: A1 Journal article – refereed
Field of Science: 115 Astronomy and space science
Funding: We acknowledge the financial support by the Academy of Finland to the ReSoLVE Centre of Excellence (project No. 272157).
Academy of Finland Grant Number: 272157
Detailed Information: 272157 (Academy of Finland Funding decision)
Copyright information: © ESO, 2017. Published in this repository with the kind permission of the publisher.