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Related papers: Mutual Validation of Datasets for Analyzing Tilt A…

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A combination of diamagnetic pumping and a nonlocal alpha-effect of the Babcock-Leighton type in a solar dynamo model helps to reproduce observations of solar magnetic activity. The period of the solar cycle can be reproduced without…

Solar and Stellar Astrophysics · Physics 2015-05-30 L. L. Kitchatinov , S. V. Olemskoy

We compare two candidate nonlinearities for regulating the solar cycle within the Babcock-Leighton paradigm: tilt quenching (whereby the tilt of active regions is reduced in stronger cycles) and latitude quenching (whereby flux emerges at…

Solar and Stellar Astrophysics · Physics 2024-12-04 Anthony R. Yeates , Luca Bertello , Alexander A. Pevtsov , Alexei A. Pevtsov

Data from the Michelson Doppler Imager (MDI) and Helioseismic and Magnetic Imager (HMI) are analyzed from 1996 to 2023 to investigate tilt angles ($\gamma$) of bipolar magnetic regions and Joy's Law for Cycles 23, 24, and a portion of 25.…

Solar and Stellar Astrophysics · Physics 2024-10-07 Lucy W. Will , Aimee A. Norton , Jon Todd Hoeksema

The purpose of this letter is to address a blind-spot in our knowledge of solar active region statistics. To the best of our knowledge there are no published results showing the variation of the Mount Wilson magnetic classifications as a…

Solar and Stellar Astrophysics · Physics 2016-03-23 Sarah A. Jaeggli , Aimee A. Norton

There is a wide range of eruptions in the solar atmosphere which contribute to space weather, including the major explosions of radiation known as flares. To examine pre-event behavior in delta-spot regions, we use here a method based on…

Solar and Stellar Astrophysics · Physics 2019-01-21 Marianna B. Korsos , Shuhong Yang , Robert Erdelyi

Understanding the global rotational profile of the solar atmosphere and its variation is fundamental to uncovering a comprehensive understanding of the dynamics of the solar magnetic field and the extent of coupling between different layers…

Images of the Sun at millimeter wavelengths obtained by ALMA show a significant correspondence with the magnetograms. In this paper, we investigate this correspondence by comparing ALMA full-disk solar image taken at 1.2 mm with a SDO/HMI…

Solar and Stellar Astrophysics · Physics 2022-03-23 I. Skokić , D. Sudar , R. Brajša

In this study we present the study of solar active regions based on BOAO vector magnetograms and $H\alpha$ filtergrams. With the new calibration method we analyzed BOAO vector magnetograms taken from the SOFT observational system to compare…

Astrophysics · Physics 2007-05-23 Y. -J. Moon , Y. D. Park , H. S. Yun , E. -A. Cho

The multi-scaled solar magnetic field consists of two major components: active regions (ARs) and magnetic network. Unraveling the cycle-dependent properties and interrelations of these components is crucial for understanding the evolution…

Solar and Stellar Astrophysics · Physics 2024-06-13 Yukun Luo , Jie Jiang , Ruihui Wang

Tilt angles of close to 30,600 sunspots are determined using Mount Wilson daily averaged magnetograms taken from 1974 to 2012, and MDI/SoHO magnetograms taken from 1996 to 2010. Within a cycle, more than 90% of sunspots have a normal…

Solar and Stellar Astrophysics · Physics 2015-06-11 Jing Li , Roger K. Ulrich

The presence of fine structures in the sunspot vector magnetic fields has been confirmed from Hinode as well as other earlier observations. We studied 43 sunspots based on the data sets taken from ASP/DLSP, Hinode (SOT/SP) and SVM (USO). In…

Solar and Stellar Astrophysics · Physics 2015-05-13 Sanjiv Kumar Tiwari , P. Venkatakrishnan , K. Sankarasubramanian

We investigate various properties associated with the tilt of isolated magnetic bipoles in magnetograms taken at the solar surface. We show that bipoles can be divided into two groups which have tilts of opposite signs, and reveal similar…

Solar and Stellar Astrophysics · Physics 2015-06-23 E. Illarionov , A. Tlatov , D. Sokoloff

The emergence of tilted bipolar active regions and the dispersal of their flux, mediated via processes such as diffusion, differential rotation and meridional circulation is believed to be responsible for the reversal of the Sun's polar…

Solar and Stellar Astrophysics · Physics 2010-09-28 Andrés Muñoz-Jaramillo , Dibyendu Nandy , Petrus C. H. Martens , Anthony R. Yeates

Solar active regions (ARs) are areas on the Sun with very strong magnetic fields where various activities take place. Prominences are one of the typical solar features in the solar atmosphere, whose eruptions often lead to solar flares and…

Solar and Stellar Astrophysics · Physics 2024-02-22 T. Zhang , Q. Hao , P. F. Chen

The power spectra of the fluctuation noise of the solar active region (AR) areas and magnetic fluxes sequentially observed in time contain information about their geometrical features and the related fundamental physical processes. These…

Solar and Stellar Astrophysics · Physics 2024-03-14 G. Dumbadze , B. M. Shergelashvili , M. L. Khodachenko , S. Poedts

The zero point of measured photospheric Doppler shifts is uncertain for at least two reasons: instrumental variations (from, e.g., thermal drifts), and the convective blueshift, a known correlation between intensity and upflows. Calibrated…

Solar and Stellar Astrophysics · Physics 2015-06-03 Brian T. Welsch , George H. Fisher , Xudong Sun

Here, we analyzed magnetic elements of the solar active regions (ARs) observed in the line-of-sight magnetograms (the 6173 \AA~Fe \small{I} line) recorded with the Solar Dynamics Observatory (SDO)/Helioseismic and Magnetic Imager (HMI). The…

Solar and Stellar Astrophysics · Physics 2021-09-28 M. A. Moradhaseli , M. Javaherian , N. Fathalian , H. Safari

In recent decades our understanding of solar active regions (ARs) has improved substantially due to observations made with better angular resolution and wider spectral coverage. While prior AR observations have shown that these structures…

The average tilt angle of sunspot groups emerging throughout the solar cycle determines the net magnetic flux crossing the equator, which is correlated with the strength of the subsequent cycle. I suggest that a deep-seated, non-local…

Solar and Stellar Astrophysics · Physics 2015-10-28 Emre Işık

Aims. Our aim is to examine the solar cycle variability of magnetically simple and complex active region. Methods. We studied simple ($\alpha$ and $\beta$) and complex ($\beta\gamma$ and $\beta\gamma\delta$) active regions based on the…

Solar and Stellar Astrophysics · Physics 2019-09-11 Shabnam Nikbakhsh , Eija Tanskanen , Maarit Käpylä , Thomas Hackman