Publication detail

Measuring Solar Differential Rotation with an Iterative Phase Correlation Method

HRAZDÍRA, Z. DRUCKMÜLLER, M. HABBAL, S.

English title

Measuring Solar Differential Rotation with an Iterative Phase Correlation Method

Type

journal article in Web of Science

Language

en

Original abstract

A reliable inference of the differential rotation rate of the solar photosphere is essential for models of the solar interior. The work presented here is based on a novel iterative phase correlation technique, which relies on the measurement of the local shift, at the central meridian, between two images separated by a given time interval. Consequently, it does not require any specific reference features, such as sunspots or supergranules, nor extended observations spanning several months. The reliability of the method is demonstrated by applying it to high spatial and temporal resolution continuum images of the solar photosphere, at 6173 A, acquired by the Solar Dynamics Observatory Helioseismic and Magnetic Imager over one complete Carrington rotation. The data selected covers the time period of 2020 January 1 to February 2. The method was applied to one day, and to the full time interval. The differential rotation rate derived using this feature-independent technique yields values that fall in the middle of the range of those published to date. Most importantly, the method is suited for the production of detailed rotation maps of the solar photosphere. It also enables the visual and quantitative identification of the north-south asymmetry in the solar differential rotation rate, when present.

English abstract

A reliable inference of the differential rotation rate of the solar photosphere is essential for models of the solar interior. The work presented here is based on a novel iterative phase correlation technique, which relies on the measurement of the local shift, at the central meridian, between two images separated by a given time interval. Consequently, it does not require any specific reference features, such as sunspots or supergranules, nor extended observations spanning several months. The reliability of the method is demonstrated by applying it to high spatial and temporal resolution continuum images of the solar photosphere, at 6173 A, acquired by the Solar Dynamics Observatory Helioseismic and Magnetic Imager over one complete Carrington rotation. The data selected covers the time period of 2020 January 1 to February 2. The method was applied to one day, and to the full time interval. The differential rotation rate derived using this feature-independent technique yields values that fall in the middle of the range of those published to date. Most importantly, the method is suited for the production of detailed rotation maps of the solar photosphere. It also enables the visual and quantitative identification of the north-south asymmetry in the solar differential rotation rate, when present.

Keywords in English

Solar rotation; Solar differential rotation; Astronomical techniques; Astronomical models; Analytical mathematics; Computational methods; Direct imaging; Astrometry; Astronomical methods; Astronomy software; Astronomy data analysis; Astronomy data visualization

Released

23.12.2020

Publisher

IOP PUBLISHING LTD

Location

BRISTOL

ISSN

0067-0049

Volume

252

Number

1

Pages from–to

1–8

Pages count

8

BIBTEX


@article{BUT167723,
  author="Zdeněk {Hrazdíra} and Miloslav {Druckmüller} and Shadia Rifai {Habbal},
  title="Measuring Solar Differential Rotation with an Iterative Phase Correlation Method",
  year="2020",
  volume="252",
  number="1",
  month="December",
  pages="1--8",
  publisher="IOP PUBLISHING LTD",
  address="BRISTOL",
  issn="0067-0049"
}