Contents
Solar flares -3D MHD simulation and observations
Flare reconnection-driven magnetic field and Lorentz force variations at the Sun’s surface
Where:
(1) Sorbonne University, Paris Observatory, LESIA, Meudon, France;
When: 2018-2019;
Collaborators:
Prof. Guillaume Aulanier (Paris Observatory, LESIA, Paris, France),
Dr. Sophie Masson (Paris Observatory, LESIA, Paris, France),
Prof. Michael S. Wheatland (University of Sydney, Sydney, Australia);
Project description:
We discuss dependencies of magnetic field, electric current density and Lorentz force in erupting flare. In addition, we focus on different methods of Lorentz force calculation. The high-spatiotemporal resolution of the 3D simulation outputs allows us a detailed study of the morphology, evolution, and dynamics, giving us a new view of processes occur in the solar flares. We compare our results of the 3D simulation with observational studies.
Results:
We find that the contraction of the inflow of the magnetic fields is determined by the currents and Lorentz forces. Additionally, we show that the surface integral coming from the volume integral of the Maxwell stress tensor, as usually used in observational data analysis as the proxy of the Lorentz force, present a different behaviour than the Lorentz force itself. The Lorentz force characterises more complicated morphology than mentioned integrand. Moreover, based on the analysis of the induction equation in the simulation, we unveil that the increase of the horizontal magnetic filed around active region PILs during eruptions is solely and exclusively result of the flare reconnection-driven contraction of flare loops. Using our simulation and observations of several flares, we found clear decrease of jz at the footpoints of the flux rope. These findings can be important in flare diagnostic. These results are published:
- ApJ, 877, 67 (2019)
Small-scale structure in the upper atmosphere of the Sun
Miniature loops in the solar corona
Where: Max-Planck-Institute for Solar System Research (MPS), Goettingen, Germany
When: 2013-2016
Collaborators:
Prof. Dr. Hardi Peter (MPS, Goettingen),
Dr. Sabrina Savage (NASA)
Project description:
Short loops with lengths only 1 Mm are well established at transition region temperatures (0.1 MK), and we investigate if such miniature loops also exist at coronal temperatures (>1 MK). We analysed extreme UV imaging (EUV) observations from the High-resolution Coronal Imager (Hi-C), imaging and magnetogram data from the SDO and X-Ray Telescope (XRT) data from Hinode.
Results:
We find that the size, motion and temporal evolution of the loop-like features are consistent with photospheric motions, suggesting a close connection to the photospheric magnetic field. The Hi-C images aligned to magnetograms show that one of their endpoints is rooted at a magnetic concentration. Their thermal structure, as revealed together with the X-ray observations, shows significant differences when compared to moss-like features. Considering different scenarios, these features are most probably miniature versions of hot loops rooted at magnetic concentrations at opposite sides of a granule in small emerging magnetic loops (or flux tubes). These results are published:
- A&A, 599, 137, 2017
- Ph.D. thesis, K.Barczynski (2017)
The Hi-C observation of the plage area. The contours A-D shows four miniature loops (A&A, 599, 137, (2017)).
Flux-flux relations in the solar atmosphere
Where:
Max-Planck-Institute for Solar System Research (MPS), Goettingen, Germany;
When: 2014-2017
Collaborators:
Prof. Hardi Peter (MPS, Goettingen)
Prof. Sami Solanki (MPS, Goettingen)
Dr. Lakshmi Pradeep Chitta (MPS, Goettingen)
Project description:
The statistical study of the flux-flux relations can be used as a proxy of unresolved small-scale structures in the solar atmosphere. It is well established that this relation between chromospheric emission and the magnetic field is nonlinear. In this project, we investigate systematically how this relation, characterised by the exponent of a power-law fit, changes through the atmosphere, from the upper photosphere to the transition region. We use spectral maps from the IRIS covering Mg II and its wings, C II, and Si IV together with magnetograms and UV continuum images from the SDO. We determine the indices (or exponents) by assuming a power-law dependency between each pair of observables.
Results:
We find that the correlation between emission and magnetic field drops monotonically with temperature and the power-law index shows a hockey-stick-type variation: from the upper photosphere to the temperature-minimum it drops sharply and then increases through the chromosphere into the transition region. It is irrespective of spatial resolution or whether we check regions of an active region, plage, quiet Sun or coronal holes. From this study, we conclude that the relations between the emission and the magnetic field below and above the temperature minimum are governed by different mechanisms: Below the geometric effect of expanding flux tubes dominates because at high magnetic field strengths these quickly fill the available chromospheric volume. Above the temperature minimum however, the increasing sensitivity of the emission on the plasma heating is most relevant. These results are published in my Ph.D. thesis.
Relation of the upper atmosphere to the underlying magnetic field in different parts of the Sun.
Panel (a) shows the Spearman correlation to the (underlying) magnetic field and panel
(b) the power-law index of the power law fit of emission feature vs. magnetic field (Barczynski, K., Ph.D. thesis).
Small-scale structures in Quiet Sun (QS) and Coronal Hole (CH)
Where:
Max-Planck-Institute for Solar System Research (MPS), Goettingen, Germany
When:
2016 -2017
Collaborators:
Prof. Hardi Peter (MPS, Goettingen)
Dr. Lakshmi Pradeep Chitta (MPS, Goettingen)
Project description:
The aim of this project is to investigate geometry, dynamics and physical properties (e.g. density, intensity, magnetic field flux, magnetic field flux density, Doppler velocity) of the small-scale structure in the QS and CH, and test the relation between small-scale structures and the underlying photospheric magnetic field. These structures can play an important role in understanding heating and energy transport in the solar atmosphere. We use data obtained by Hinode/NFI, IRIS, SDO/AIA and SDO/HMI. We make a focus on two structures: (1) a small-scale cool loop observed in Si IV IRIS raster map which occurs only for short time in IRIS/SJI1400 images; (2) two magnetic patches with similar magnetic flux densities but with different response in the upper chromosphere and transition region.
Results:
In the case (1) of small-scale cool loop we suggest that we observe both heating and cooling phases of the loop. In the case (2) of two magnetic field patches, they are in different stages of convective collapse with different inclinations, leading to different response in the higher atmospheric layers. These results are published in my Ph.D. thesis.
The two magnetic field patches in the different observables (Barczynski, K., Ph.D. thesis).
Propagating disturbances in closed coronal loops
Where:
Max-Planck-Institute for Solar System Research (MPS), Goettingen, Germany
Sorbonne University, Paris Observatory, Paris, France
When:
2017 -…
Collaborators:
Prof. Hardi Peter (MPS, Goettingen)
Dr. Lakshmi Pradeep Chitta (MPS, Goettingen)
Project description:
The origin of propagating disturbances observed as small-scale brightenings moving along a coronal loop is still an open issue. To address this, we study observations of disturbances in a coronal loop propagating from the temperature – minimum region into the corona and relate this to the underlying photospheric magnetic field. These observations suggest that the magnetic field evolution plays an essential role in generating the observed disturbances. To investigate the evolution of the propagating disturbance and their relation to the underlying magnetic field, we use imaging diagnostics of the solar atmosphere (IRIS, SDO/AIA) and photospheric magnetic field maps (HINODE, SDO/HMI).
Result:
We looked for propagating disturbance in the closed coronal loops in 70 different regions. We find only one propagating disturbance in the closed coronal loops. This suggests that propagating disturbance in closed coronal loops are rare. Therefore, we decided to investigate further a unique example of propagating disturbance in closed coronal loop. We find a time delay in the intensity maxima of propagating disturbances that increase from the temperature minimum through the chromosphere into the corona. The propagating disturbance shows a clear quasi-periodicity of about 10 min. In the highly inclined loop, the apparent speeds of propagating disturbances increase from the transition region (∼20 km/s) to the corona (∼70 km/s), suggesting that these disturbances are subsonic. Our preliminary results show that the evolution of small-scale magnetic field concentrations at the base of the loop is tightly connected to the generation of propagating disturbance. We suggest that propagating disturbances are governed by the reconnection of small-scale magnetic field structures in the vicinity of coronal loop footpoints. The energy converted in the reconnection process is transported upwards by heat conduction. In the upper atmosphere, the apparent motion of the heat- front is then observed as a propagating disturbance.
Solar plume
Dynamics of solar polar plumes
Where:
(1) Observatory in Upice, Czech Republic;
(2) Astronomical Observatory of the Jagiellonian University, Krakow, Poland;
When: 2009-2013;
Collaborators:
Dr. Eva Markova (Observatory in Upice, Czech Republic),
Dr. Vojtech Rusin (Slovak Academy of Sciences) and
Dr. hab. Grzegorz Michalek (Jagiellonian University, Krakow, Poland);
Project description:
Results:
- 2010nspm.conf..134B
- CoSka42, 125; SoPh
- SoPh, 284, 439, 2013
- Master thesis, K. Barczynski (2013)
Instrumental projects
The solar interferometer (student project)
Where:
Astronomical Observatory of the Jagiellonian University (Electronic Laboratory), Krakow, Poland
When: 2010
Collaborators:
Dr. hab. Andrzej Kulak (Jagiellonian University)
Julia Sudyka (student, Jagiellonian University)
Project description:
The aim of the project was to design and build an interferometer to observe the solar activity. I was one of the two students team.
Results:
We prepared a design of electronic circuit of the interferometer (at a central wavelength of 810 MHz) and simulated the amplifiers and filters in PSpice to choose the best solutions. We designed and prepared printed circuit boards and installed the necessary electronic components (including Surface Mounted Devices) to the printed circuit boards. We tested both the individual modules and the whole interferometer.
Tests of interferometer modules (right) and first results (right).
Solar radio astronomy flux monitoring
Where:
Astronomical Observatory of the Jagiellonian University, Krakow, Poland;
When: 2010-2013
Collaborators:
Dr. hab. Andrzej Kulak (Jagiellonian University)
eng. Jerzy Kubisz (Jagiellonian University)
Project description:
This project was a continuation of daily solar flux measurements that have been conducted in the Astronomical Observatory of Jagiellonian University in Krakow since 1957. The automatic radio telescope (8m dish diameter) measures solar flux at 403, 1580 and 2800 MHz.
Results:
I developed a method of data calibration (2010-2012). I suggested and provided (2012-2013) a test that allowed us to identify the source of the radio noise at 2800 MHz. Based on several tests and discussion with engineers, we defined a new observational strategy and modified the radio-telescope (hardware and software). The new strategy was partially implemented by engineers (hardware) and programmers (software). However, the instrument has been damaged during a thunder storm (June 2013) and the project had been temporarily suspended. The archive data of solar radio observations.
Radio telescope (RT-8, single-dish radio telescope with a diameter of 8m)
uses to radio observations of the Sun, Krakow, Poland
Collaboration with Extremely Low Frequency (ELF) group
Where:
Astronomical Observatory of the Jagiellonian University, Krakow, Poland
When:2011-2013
Collaborators:
Dr. hab. Andrzej Kulak (Jagiellonian University)
eng. Jerzy Kubisz (Jagiellonian University);
Project description:
The aim of the project is to study the role of Extremely Low Frequency (ELF) electromagnetic waves in geophysics, astrophysics and atmospheric science.
Results:
I participated in the working group meetings (2011-2013). I participated in the testing and installation of the on-line data transfer system from the ELF station “Hylaty” (at the Bieszczady Mountains, Poland) using GSM transmission (in a mountain area with poor GPS coverage). I co-installed ELF radio-station in Giant Mountains (Poland). I was also responsible for cost optimization of transport and installation of the ELF station in South America.
July 2013, Preparation to installation a new station, Giant Mountains, Poland