Conveners
Poster Session 1.1
- Etienne Pariat (LESIA, Observatoire de Paris)
The rotation rates of solar active and ephemeral regions depend on morphology and size of magnetic structures, although the reasons of the dependence are still being discussed. The aim of the work is to analyze the rotation rates of different types of magnetic tracers using magnetic field data rather than white-light images.
Magnetic field maps provided by the Helioseismic and Magnetic...
We use SOHO and SDO data to study 2046 active regions (ARs) of the 23rd and 1507 ARs of the 24th solar cycles. According to empiric regularities for sunspot groups (Hale’s polarity law, Joy’s law, etc.) and the magneto-morphological classification (MMC), all ARs were divided into three types: A-type – regular bipolar ARs; B-type – irregular ARs that violate at least one of empiric rules;...
We present a catalog of bipolar active regions (ARs) violating Hale's polarity law over the period 1989–2018. The catalog is compiled based on visual inspection of solar data in web applications Debrecen Photoheliographic Data, Helioviewer and Solar Monitor. Also, data from catalogs of the Mount Wilson Observatory, Crimean Astrophysical Observatory (CrAO) and USAF/NOAA SRS were used. The...
We investigate how representing active regions with bipolar magnetic regions (BMRs) affects the end-of-cycle polar field predicted by the surface flux transport model. Our study is based on a new database of BMRs derived from the SDO/HMI active region patch data between 2010 and 2020. An automated code is developed for fitting each active region patch with a BMR, matching both the magnetic...
In various classes of dynamo models, spot-producing magnetic fields are generated as axisymmetric toroidal flux-ropes. While mean-field models produce axisymmetric broad toroidal fields, full 3D convective models produce axisymmetric toroidal wreaths. All these models can reproduce various longitude-averaged features, such as solar-like butterfly diagrams. In recent simulations, we show that...
The regular observation of the solar magnetic field is available only for about last five cycles. Thus, to understand the origin of the variation of the solar magnetic field, it is essential to reconstruct the magnetic field for the past cycles, utilizing other datasets. Long-term uniform observations for the past 100 years as recorded at the Kodaikanal Solar Observatory (KoSO) provide such an...
We use statistical tools to analyse data from HMI to determine the magnetic flux distribution of photospheric magnetic features and its variation over a solar cycle. The nature of the observed flux distributions at different times during the solar cycle could be used to try and infer information about magnetic field generation mechanisms. In particular we compare whether the magnetic flux...
