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Solarnet International Conference
The Physics of the Sun from the Interior to the Outer Atmosphere Free Conference is closed
Conference is closed
solarnet4
Affiliation Leibniz-Institut für Sonnenphysik
Arrecife, Lanzarote, Spain
14.01.2017 - 19.01.2017

Organizing institutions
Instituto de Astrofísica de Canarias (IAC)
Main category Natural Sciences (Astrophysics and Astrononmy)
Conference/Workshop objectives
The 4th SOLARNET meeting "The physics of the Sun from the interior to the outer atmosphere" will take place in Arrecife, Lanzarote (Spain) from 16th to 20th of January 2017, organized by the Instituto de Astrofísica de Canarias (IAC). The purpose of this conference is to provide a coherent picture of the Sun as a single physical system playing all the underlying physical processes measured and observed in the solar atmosphere to date. Graduate students and early-career postdocs are particularly invited to participate in the conference to present their research work and to meet and discuss with their more senior colleagues. This conference is expected: 1) to provide a forum to discuss recent advances in the study of the solar interior, solar dynamics and dynamo, mechanisms of sunspot and active regions formation, and links between the subsurface dynamics, flaring and CME activity; 2) to identify the new problems in the study of the solar interior and atmosphere, and of the solar dynamics and magnetism; 3) to foster collaborations between researchers working at the study of the Sun’s interior and solar atmosphere and to create synergies between solar research programs at different wavelength bands.
Local organizing committee

Elena Khomenko (chair)
María Jesús Martínez González (co-chair)
Iñigo Arregui
Melania Cubas Armas
Carlos José Díaz Baso
Reza Rezaei
Beatrice Popescu Braileanu
Alberto Escobar Rodríguez
Manuel Collados

Scientific Organization Committee:
Elena Khomenko (IAC, chair) 
María Jesús Martínez González (IAC, Spain, co-chair) 
Alina Donea (Univ. Monash, Australia) 
Mausumi Dikpati (HAO, USA) 
Natasha Shchukina (MAO, Ukraine) 
Francesca Zuccarello (Univ. Catania, Italy) 
Aimee Norton (Univ. Stanford, USA) 
Lindsey Fletcher (Univ. Glasgow, UK) 
Ineke de Moortel (Univ. St. Andrews, UK) 
Emilia Kilpua (Univ. of Helsinki, Finland)

Contact:
Elena Khomenko
Instituto de Astrofísica de Canarias
c/ Vía Láctea s/n
38200 La Laguna (Tenerife)
Spain

e-Mail: solarnet4m(at)iac.es

Scientific organizing committee (SOC)

Elena Khomenko (IAC, chair)
María Jesús Martínez González (IAC, Spain, co-chair)
Alina Donea (Univ. Monash, Australia)
Mausumi Dikpati (HAO, USA)
Natasha Shchukina (MAO, Ukraine)
Francesca Zuccarello (Univ. Catania, Italy)
Aimee Norton (Univ. Stanford, USA)
Lindsey Fletcher (Univ. Glasgow, UK)
Ineke de Moortel (Univ. St. Andrews, UK)
Emilia Kilpua (Univ. of Helsinki, Finland)

Sessions
  • 1. Solar internal structure from helioseismology
  • 2. Solar cycle: convection, rotation, dynamo, and flux emergence
  • 3. Theoretical radiative transfer and spectropolarimetry
  • 4. Photospheric dynamics and magnetism
  • 5. Chromospheric dynamics and magnetism
  • 6. Corona and transition region: dynamics, magnetic fields and heating mechanisms
  • 7. Energetic events, flares and CMEs and space weather
  • 8. Upcoming telescopes and instruments
Programme
Invited speakers

 

Invited Reviews:

Andreas Lagg "Measurements of photospheric magnetic fields"
Ann Marie Broomhall "Solar internal structure and dynamics"
Astrid Veronig "Solar eruptions and energetic events"
Consuelo Cid "Solar energetic events and space weather"
Iñigo Arregui "Heating of the solar corona"
Jaime de la Cruz "Non-LTE chromospheric diagnostics and inversions"
Rob Rutten "Observations and diagnostics of the solar chromosphere"
Sarah Gibson "Dynamics and diagnostics of the solar corona"
Sarah Matthews "Science with European Solar Telescope"
Yuhong Fan "Differential rotation and solar convective dynamo"

 

Invited Talks:

Ada Ortiz
Adur Pastor Yabar
Ariane Schad
Haruhisa Iijima
Jiri Stepan
Lauren Jouve
Maarit Käpylä
Marilena Mierla
Nazaret Bello Gonzalez
Nicki Viall
Philippa Browning
Rebecca Centeno
Tiago Pereira
Tobias Felipe
Tony Arber

 

 

Special session on "Upcoming telescopes and instruments":

 
Jose Carlos del Toro Iniesta "Solar Orbiter mission"
Masahito Kubo "Results and future of CLASP project"
Hans-Peter Doerr "Sunrise III project"
Valentín Martínez Pillet "DKIST telescope"

Important dates August 15, 2016: Registration opens October 1, 2016: Deadline for applications for financial support November 1, 2016: Abstract submission deadline and Registration form submission deadline November 23, 2016: Deadline of early bird registration fee payment
Registration and payment information

The registration includes conference material, all lunches, coffee breaks, one organised tour, and one conference dinner.

Early bird registration fee payment until November 16, 2016: € 350,- per person
Registration fee PhD students: € 200,- per person
Late registration after November 16, 2016: € 450,- per person
Registration for accompanying persons: € 100,- per person (tour and conference dinner)

 

Payment can be done in two ways:
Credit card:
Only VISA or MASTERCARD are acepted.
Please print the CREDIT CARD PAYMENT FORM, fill in all applicable fields with capital letters, scan it, and send by fax to
+34 922 605 210
or by email to solarnet4m(at)iac.es

In case you submit the form via fax, please send also an email to LOC at solarnet4m(at)iac.es

Wire transfer:
Please contact the LOC at solarnet4m(at)iac.es or the bank coordinates.

PLEASE NOTE: No payment will be accepted at the conference!
The receipt for your registration fee and a copy of the amount charged to your credit card or bank account will be attached to the conference material that you will get at the Registration Desk, upon arrival.

Should you need to cancel your registration, please inform the LOC by email to solarnet4m(at)iac.es

Conference venue Arrecife, Lanzarote, Spain
Hotel information We encourage the participants to perform early reservations of the accomodation. To book your accommodation with a special offer, please fill this form and send to: tci-suarezguerra@bthetravelbrand.com Lanzarote in January is a very requested touristic destination. IMPORTANT: We can not guarantee the availability of accomodation in the hotels indicated below after November, 30, 2016 Arrecife Gran Hotel - Conference venue It is a five stars hotel in Arrecife, the main city of Lanzarote. The prices of the rooms are (all includebuffet breakfast): room type 1 person 2 persons double standard 120€ 160€ suite 160€ 200€ Hotel Lancelot It is a more modest 3 star hotel very close to the conference venue. We have special prices for the conference. This does not mean that we can obtain better prices than many tour-operators. The prices of the rooms are given below. Single standard 62.00€ Double standard 72.00€ Hotel Diamar It is a more modest 3 star hotel very close to the conference venue. We have special prices for the conference. This does not mean that we can obtain better prices than many tour-operators.The prices of the rooms are given below. Single volcano view 62.00€ Double volcano view 74.00€
Travel information Visa applications In case you need letters of invitation for visa application please contact the LOC: Mail: solarnet4m(at)iac.es Tel.: +34-922605319 Travel information The Canary Islands are rather remote from continental Europe, however their connection by air is extremely good. The international airport of Lanzarote: Arrecife (ACE), is connected by daily regular flights from Madrid and Barcelona. There are also regular flights from London and charter flights from many other European airports. Moreover, there are frequent daily connections to the international airports of the two largest islands of the archipelago: Gran Canaria (LPA) and Tenerife (TFN and TFS airports). How to reach the Hotel? You can arrive to the hotel (see map) by bus, taxi, or renting a car. The bus service -here buses are called "guaguas"- run frequently and cheaply and are quite comfortable. If you arrive during the weekend, you could take the bus Line 23, which connects the airport with Arrecife and it has a bus stop in Gran Hotel. The trip takes around 10 minutes and they come each 50 minutes. It costs about 1 €. More info in the Arrecife Bus webpage (http://www.arrecifebus.com/). By taxi would cost about 15-20 € and takes around 10 minutes. The taxi stop is at the exit of the airport. Renting a car may also be an alternative, since car rentals in Lanzarote are rather cheap and of very good quality. Autos Reisen and Autos Cabrera-Medina generally offer the best rates. You can find prices as low as 25 € per day.
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SOLARNET - High Resolution Solar Physics Network

Session: 8. Upcoming telescopes and instruments

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Date of upload:
26.08.2015
Co-author:
IACvideos
Caption:
The European Solar Telescope (EST) is the future project for European ground-based solar astronomy. It is the main project for EAST (European Association for Solar Telescopes), an association with 15 member institutions from 15 European countries.
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SOLARNET - High Resolution Solar Physics Network

Session: 8. Upcoming telescopes and instruments

1333 views
Date of upload:
26.08.2015
Co-author:
The EST Consortium
Caption:
The European Solar Telescope (EST) is of major interest for all the European Solar Community, since it will help to maintain Europe on the top of science, Solar Physics, and technology. The EST design study was funded by the European Commission's 7th Framework Programme under contract number FP7-212482.
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SOLARNET - High Resolution Solar Physics Network

Session: 1. Solar internal structure from helioseismology

508 views
Date of upload:
14.01.2017
Co-author:
Abstract:
These slides give a short overview on how to upload conference contributions, e.g. slides, posters, videos, papers to ScienceMedia and link it with the Solarnet4 Conference. $\alpha$
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Jörn Warnecke

Session: 2. Solar cycle: convection, rotation, dynamo, and flux emergence

516 views
Date of upload:
16.01.2017
Co-author:
Petri Käpylä, Maarit Käpylä, Axel Brandenburg, Matthias Rheinhardt
Abstract:
The magnetic field in the Sun undergoes a cyclic modulation with a reversal typically every 11 years due to a dynamo operating under the surface. We simulate a solar-type star, where the interplay between convection and rotation self-consistently drives large-scale magnetic field. We apply the test-field method to characterize the dynamo mechanism acting in this simulation by determining 27 turbulent transport coefficients of the electromotive force, of which 9 are related to the $\alpha$ effect tensor. We find that the alpha-effect has a complex nature and does not follow the profile expected from kinetic helicity. Besides the dominant $\alpha$-$\Omega$ dynamo, also an $\alpha^2$ dynamo is locally enhanced. The turbulent pumping velocities significantly alter the effective mean flows acting on the magnetic field and therefore challenge the flux transport dynamo concept. All coefficients are significantly affected due to dynamically important magnetic fields with quenching as well as enhancement being observed. This leads to a modulation of the coefficients with the activity cycle.
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Anne-Marie Broomhall

Session: 1. Solar internal structure from helioseismology

491 views
Date of upload:
17.01.2017
Co-author:
Abstract:
Helioseismology uses the Sun’s natural oscillations to probe beneath the surface of the Sun. Over the past several decades helioseismology has proven extremely successful at providing insights into the interior of the Sun: We have learnt about the structure of the solar interior, including the depth of the convection zone, we have learnt about the composition of the Sun, and we have learnt about rotation and other internal flows. I will review our current understanding of the solar interior based upon helioseismic results, and describe how the Sun’s interior varies over timescales commensurate with the solar cycle. For example, although it is difficult to detect solar-cycle related structural changes in the deep interior, variations in rotation have been observed in the form of the torsional oscillation. I will also discuss some of the remaining challenges for helioseismologists to address, including the search for internal gravity modes, whose detection would substantially advance our ability to infer properties of the structure and dynamics of the deep solar core.
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Christoph Kuckein

Session: 5. Chromospheric dynamics and magnetism

642 views
Date of upload:
18.01.2017
Co-author:
A. Diercke, S.J. González Manrique, M. Verma, M. Sobotka, J. Löhner-Böttcher, H. Balthasar, and C. Denker
Abstract:
The GREGOR Fabry-Perot Interferometer (GFPI) is installed at the 1.5-meter GREGOR telescope on Tenerife, Spain. The coatings of the etalons of the GFPI have a high reflectivity in the wavelength range between 530-860 nm. Therefore, during a 50-day first-science campaign in 2014 the chromospheric Ca II 854.2 nm line was observed with the GFPI in spectroscopic mode. The target was a group of pores close to disk center in active region NOAA 12149 on 2014 August 26. A non-equidistant wavelength spacing to scan through the broad Ca II 854.2 nm line was used. Narrower step sizes were taken close to the line core. Each of the 20 scans comprised 36 steps. Four images with an exposure time of 80 ms were acquired per step. We will present some physical properties of the group of pores derived from the inversions of the Ca II 854.2 nm intensity profiles using the non-LTE radiative transfer code NICOLE. This code is especially useful to infer atmospheric parameters from chromospheric lines formed under non-LTE conditions.
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Sergio Javier González Manrique

Session: 5. Chromospheric dynamics and magnetism

834 views
Date of upload:
19.01.2017
Co-author:
S.J. González Manrique, C. Kuckein, A. Pastor Yabar, M. Collados, C. Denker, M. Verma, A. Diercke, P. Gömöry, H. Balthasar, M. Cubas Armas, A. Lagg, S.K. Solanki, and K.G. Strassmeier
Abstract:
The new generation of solar instruments provides better spectral, spatial, and temporal resolution, which is essential to investigate the physical processes that take place on the Sun. High-resolution observations often show double- or even multiple-component spectral profiles. This is particularly true for observations of the near-infrared He I 10830 Å triplet. These spectral lines provide information on the velocity and magnetic fine structure of the upper chromosphere. We present observations of an emerging flux region (EFR), including two small pores visible in the photosphere and an arch filament system (AFS) in the chromosphere. The data were taken on 2015 April 17 with the very fast spectroscopic mode (~1 min for a full scan of 180 steps) of the GREGOR Infrared Spectrograph (GRIS), one of the post-focus instruments of the 1.5-meter GREGOR solar telescope located at the Observatorio del Teide, Tenerife, Spain. Simultaneous spectroscopic observations were taken with the GREGOR Fabry-Pérot Interferometer (GFPI) of the photospheric Fe I 6302 Å line. On the island of La Palma, the Swedish Solar Telescope (SST) observed the same EFR using the CRisp Imaging Spectro-Polarimeter (CRISP), which recorded spectropolarimetric data in the photospheric Fe I 6173 Å and the chromospheric Ca II 8542 Å lines. The observed AFS connects the two opposite magnetic polarities of newly emerging flux. Supersonic downflows up to 100 km s$^{-1}$ were measured in the He I triplet, which occur near both footpoints of dark filaments, whereas loop tops rise with about 1.5–20 km s$^{-1}$. The aim of this work is to track locations of high velocities within the footpoints of the arch filaments down to the photosphere. A special question arises, if the plasma contained in chromospheric structures, which exhibits supersonic LOS downflows near the footpoints of the AFS even reaches the photosphere.
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Paolo Pagano

Session: 6. Corona and transition region: dynamics, magnetic fields and heating mechanisms

532 views
Date of upload:
19.01.2017
Co-author:
Ineke De Moortel
Abstract:
Recent observations of coronal loops reveal ubiquitous transverse velocity perturbations, that undergo strong damping as they propagate. Observational estimates show that these perturbations contain significant amounts of energy. We have previously demonstrated that this observed rapid damping can be understood in terms of coupling of different wave modes in the inhomogeneous boundaries of the loops: this mode coupling leads to the coupling of the transversal (kink) mode to the azimuthal (Alfvén) mode, observed as the decay of the transverse kink oscillations. However, an important point to note here is that (observed) wave damping does not automatically imply dissipation, and hence heating. To investigate under which circumstances this process can contribute to the coronal heating and to what extend the heating rate is sustainable, we perform 3D numerical experiments modelling the observed, transverse oscillations including the effects of resistivity and thermal conduction. We first analyse the contribution from a single monochromatic pulse, and then we extend the study by investigating different sizes and structures of the boundary layer and a continuous driver.
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Meetu Verma

Session: 4. Photospheric dynamics and magnetism

740 views
Date of upload:
19.01.2017
Co-author:
C. Denker, H. Balthasar, C. Kuckein, Reza Rezai, M. Sobotka, N. Deng, H. Wang, A. Tritschler, M. Collados, A. Diercke, S.J. González Manrique
Abstract:
Active region NOAA 12597 emerged on 22 September 2016 in southern hemisphere. The region was observed two days later on 24 September 2016 with GREGOR, VTT, NST, and Hinode during a campaign organized as part of the SOLARNET initiative for coordinated observing campaigns. The leading spot of the region was observed for the next four days. We obtained high-resolution imaging, spectroscopic, and spectropolarimetric data in various spectral lines covering the photosphere as well as the chromosphere. These data were complemented by synoptic line-of-sight magnetograms and continuum images obtained with the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO) and slit-jaw images from the Interface Region Imaging Spectrograph (IRIS). We will present the dataset taken on 24 September 2016 containing the leading spot. The sunspot was at its maximum growth and slowly started to disintegrate at the time of GREGOR and VTT observations followed by the observations from Hinode and NST a few hours later. We will discuss the photospheric and chromospheric flow fields along with the magnetic fields during the penumbral decay of a large penumbral sector. The penumbral filaments do not simply vanish but intermingle with the nearby granules and even temporarily form darkened areas resembling umbral cores filled with umbral dots.
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Sanjay gosain

Session: 8. Upcoming telescopes and instruments

605 views
Date of upload:
25.01.2017
Co-author:
Joe Staiger, Markus Roth
Abstract:
Presentation given at Solarnet 4 at Lanzarote, Spain during Jan 2017
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Sanjay gosain

Session: 5. Chromospheric dynamics and magnetism

651 views
Date of upload:
25.01.2017
Co-author:
Abstract:
Presentation given at Solarnet 4 meeting at Lanzarote, Spain, during Jan 2017. The presentation is about Chromospheric Vector Fields derived using Ca II 854 nm spectral line observations from SOLIS/VSM instrument at NSO.
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Irina Thaler

Session: 1. Solar internal structure from helioseismology

678 views
Date of upload:
31.01.2017
Co-author:
Vigeesh G., Roth, M.
Abstract:
Halo formation in realistic 3D MHD simulations Thaler I., Vigeesh G., Roth, M. Since the first discovery of acoustic halos around magnetic regions by (Brown 1992, Toner and LaBonte 1993) many observational and theoretical studies have been undertaken to better understand this phenomena. The currently most accepted theory for its formation is the refraction of fast magnetic waves in the solar atmosphere, which then leads to the observed power access in doppler velocity maps compared to the quiet sun (Khomenko & Collados 2009, e.g. Rijs 2016). Along with that we want to investigate if we can confirm these results using non-linearized wave propagation through a sunspot stripe in fully convective 3D MHD simulations using the STAGGER code.
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SOLARNET - High Resolution Solar Physics Network

Session: 8. Upcoming telescopes and instruments

691 views
Date of upload:
02.02.2017
Co-author:
Abstract:
Author: Sarah Matthews and the EST team
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SOLARNET - High Resolution Solar Physics Network

Session: 8. Upcoming telescopes and instruments

622 views
Date of upload:
02.02.2017
Co-author:
Abstract:
Author: Robbe Vansintjan
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Johannes Löhner-Böttcher

Session: 8. Upcoming telescopes and instruments

619 views
Date of upload:
19.01.2017
Co-author:
Wolfgang Schmidt, Rolf Schlichenmaier, Nazaret Bello González, Franziska Stief
Abstract:
The Laser Absolute Reference Spectrograph (LARS) is a novel scientific instrument for solar observations with the Vacuum Tower Telescope (VTT) on Tenerife. It works as a combination of the high-resolution Echelle Spectrograph of the VTT with an state-of-the-art, ultra-precise Laser Frequency Comb. The solar spectrum is then calibrated by the Frequency Comb spectrum on an absolute scale. Resulting Doppler shifts of spectral lines reach an accuracy of m/s. In this talk, I will present systematic observations of the convective blue-shift in the solar photosphere. The recent data reveal the absolute velocities and the center-to-limb variation for several spectral lines in the visible spectral range. I will present the bisectorial C-shape profiles and systematical variations for Fe I 630.15nm. On behalf of the SOLARNET project, I want to encourage the audience to perform Service-Mode operations with LARS. Co-observations with other telescopes and instruments would provide e.g. spectro-polarimetric solar observations on an absolute wavelength scale.
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SOLARNET - High Resolution Solar Physics Network

Session: 1. Solar internal structure from helioseismology

426 views
Date of upload:
12.02.2017
Co-author:
Abstract:
Talk given by Laurene Jouvé
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SOLARNET - High Resolution Solar Physics Network

Session: 1. Solar internal structure from helioseismology

482 views
Date of upload:
12.02.2017
Co-author:
Abstract:
Talk by Dário Passos
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SOLARNET - High Resolution Solar Physics Network

Session: 2. Solar cycle: convection, rotation, dynamo, and flux emergence

482 views
Date of upload:
12.02.2017
Co-author:
Abstract:
Talk by Yuhong Fan
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SOLARNET - High Resolution Solar Physics Network

Session: 2. Solar cycle: convection, rotation, dynamo, and flux emergence

473 views
Date of upload:
12.02.2017
Co-author:
Abstract:
Talk by Roxane Barnabé
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SOLARNET - High Resolution Solar Physics Network

Session: 2. Solar cycle: convection, rotation, dynamo, and flux emergence

624 views
Date of upload:
12.02.2017
Co-author:
Abstract:
Talk by Adur Pastor Yabar
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SOLARNET - High Resolution Solar Physics Network

Session: 2. Solar cycle: convection, rotation, dynamo, and flux emergence

429 views
Date of upload:
12.02.2017
Co-author:
Abstract:
Talk by Marianne Faurobert
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SOLARNET - High Resolution Solar Physics Network

Session: 2. Solar cycle: convection, rotation, dynamo, and flux emergence

634 views
Date of upload:
12.02.2017
Co-author:
Abstract:
Talk by Emre Isik
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SOLARNET - High Resolution Solar Physics Network

Session: 2. Solar cycle: convection, rotation, dynamo, and flux emergence

570 views
Date of upload:
12.02.2017
Co-author:
Abstract:
Talk by Antoine Strugarek
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SOLARNET - High Resolution Solar Physics Network

Session: 2. Solar cycle: convection, rotation, dynamo, and flux emergence

686 views
Date of upload:
12.02.2017
Co-author:
Abstract:
Talk by Frederick Gent
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SOLARNET - High Resolution Solar Physics Network

Session: 3. Theoretical radiative transfer and spectropolarimetry

672 views
Date of upload:
17.02.2017
Co-author:
Abstract:
Talk by Ivan Milic
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Vincent Böning

Session: 1. Solar internal structure from helioseismology

765 views
Date of upload:
09.05.2017
Co-author:
Shukur Kholikov, Jason Jackiewicz, Markus Roth
Abstract:
In this study, we present first inversion results for deep meridional flow using spherical Born approximation kernels and time-distance helioseismology. The computation of Born approximation kernels for flows has only recently become available in spherical geometry. Compared to the ray approximation, the Born approximation is considered to provide a more realistic model of the advection and scattering processes in the solar interior, which are captured in travel time measurements. We first validate this method using artificial data from a linear 3D simulation of solar interior wave propagation. We find that the prediction of the Born approximation model coincides well with the simulated data. We then perform standard SOLA inversions of the solar meridional flow. First, inversion results of the simulated data are discussed and compared to the original flow profile included in the simulation. Finally, we apply the validated method to GONG data spanning periods of low, medium and high solar activity (2001-2003, 2004-2006, and 2007-2009). The results are discussed and compared to literature.
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Paolo Pagano

Session: 7. Energetic events, flares and CMEs and space weather

553 views
Date of upload:
16.01.2017
Co-author:
Duncan Mackay, Anthony Yeates
Abstract:
We propose a new efficient and accurate modelling technique suitable for the next generation of Space Weather predictive tools. Specifically, we put forward an approach that can provide interplanetary Space Weather forecasting models with an accurate time dependent boundary condition of erupting flux ropes in the upper Solar Corona. The unique strength of this technique is that it follows the time evolution of coronal magnetic fields directly driven from observations and captures the full life span of magnetic flux ropes from formation to ejection. To produce accurate and effective boundary conditions we couple two different modelling techniques, MHD simulations with quasi-static non-potential modelling. Our modelling approach uses a time series of observed synoptic magnetograms to drive the non potential evolution model of the coronal magnetic field to follow the formation and loss of equilibrium of magnetic flux ropes. Following this a MHD simulation captures the dynamic evolution of the ejection phase of the flux rope into interplanetary space. We focus here on the MHD simulation that describe the ejection of two magnetic flux ropes through the solar corona to the outer boundary. At this boundary we then produce time dependent boundary conditions for the magnetic field and plasma that in the future may be applied to interplanetary space weather prediction models. We illustrate that the coupling of observationally derived quasi-static nonpotential magnetic field modelling and MHD simulations can significantly reduce the computational time for producing realistic observationally derived boundary conditions at the boundary between the corona and interplanetary space.
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Markus Roth

Session: 8. Upcoming telescopes and instruments

737 views
Date of upload:
16.01.2017
Co-author:
Sanjay Gosain, Frank Hill, Michael Thompson
Abstract:
High-resolution telescopes (such as SST, GREGOR and the future EST and ATST) allow observations of only a small fraction of the solar surface. Real-time context data showing the large-scale dynamics and magnetism at different layers of the solar atmosphere are crucial to understand the global behavior of solar phenomena. However, despite the amount of information coming from space and ground-based full-Sun telescopes, real-time information about the variation of important parameters such as velocities, magnetic field and intensity at different solar layers is stilllacking. To this aim, a network of telescopes with a small aperture but a large field-of-view can provide useful data to prepare observing campaigns with large-aperture high-resolution telescopes and complement the data taken with them. Distributed in a worldwide network, these small apertures can represent an invaluable supporting tool for coordinated observations with the major infrastructures. Within this Joint Research Activity under Solarnet, the definition of an adequate network of small telescopes, as well as the most suited instrumentation was addressed.
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Johannes Löhner-Böttcher

Session: 1. Solar internal structure from helioseismology

1587 views
Date of upload:
19.01.2017
Co-author:
Wolfgang Schmidt
Abstract:
LARS is an Absolute Reference Spectrograph. It performs fiber-coupled solar observations with the high-resolution Echelle Spectrograph of the Vacuum Tower Telescope (VTT) at the Observatorio del Teide on Tenerife. The scientific instrument is operated by the Kiepenheuer Institute for Solar Physics, Freiburg. The spectral observation is supported by a Laser Frequency Comb which serves as an absolute ruler for the wavelength calibration of the solar spectrum. This novel technique of spectroscopic observations allows the determination of absolute velocities in the solar atmosphere with the best accuracy (m s-1).
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Peter Leitner

Session: 4. Photospheric dynamics and magnetism

1552 views
Date of upload:
19.01.2017
Co-author:
B. Lemmerer, A. Hanslmeier, T. Zaqarashvili, A. Veronig, H. Muthsam
Abstract:
Small granules that do not originate from the fragmentation process of regular sized granular cells and evolve on a considerably shorter timescale populate the intergranular lanes. They are found in high-resolution observational and hydrodynamic simulation data of the quiet sun's photosphere. We study their topology and dynamics based on a segmentation algorithm. The flow field suggests that they represent high-vortical jet-like structures that are found to differentially rotate about their center axis. Their associated high horizontal kinetic energy flux exceeds that of regular granules and may excite significant Poynting flux through MHD kink waves and torsional Alfven waves that would be high enough to effectively heat the chromosphere and corona if only 10% of the wave energy is assumed to be dissipated into heat.
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MARÍA MONTES

Session: 6. Corona and transition region: dynamics, magnetic fields and heating mechanisms

2948 views
Date of upload:
22.01.2017
Co-author:
I. Arregui
Abstract:
Damping of transverse waves in different solar coronal structures is a commonly observed property and a source of information about coronal conditions. Although resonant damping seems to be the most accepted mechanism for damping of transverse waves, there are other possible mechanisms. We have carried out a Bayesian analysis comparing three different models which could explain the damping in coronal loops. Our results indicate that resonant absorption is the most probable mechanism for low ratios between damping time and wave period, while the wave leakage mechanism is the best candidate for high ratios. Nonetheless, the evidence for one model against another shows a strong dependence on the data errors.
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