Speaker: Prof Philippa Browning (University of Manchester)
Title: Heating and particle acceleration in twisted flux ropes in solar and stellar flares
Zoom link: https://zoom.us/j/95338171418
Meeting ID: 953 3817 1418

Abstract:
Twisted magnetic flux ropes are reservoirs of free magnetic energy. I will describe some recent advances in modelling plasma heating and non-thermal particle acceleration in twisted magnetic flux ropes in the context of solar flares. After an overview of twisted magnetic flux ropes in the corona, I will show how magnetic reconnection in fragmented current structures in kink-unstable twisted loops can both heat plasma and efficiently accelerate both electrons and ions. Forward modelling of the observational signatures of this process in EUV, hard X-rays and microwaves will be described, and the potential for observational identification of twisted magnetic fields in the solar corona discussed. Furthermore, the reconnection activity can drive oscillations which may be observable as oscillations in the microwave emission.
Then, coronal loops with multiple twisted threads will be considered, showing how instability in a single unstable twisted thread may trigger reconnection with stable neighbours, releasing their stored energy and causing an “avalanche” of heating events, with important implications for solar coronal heating. This avalanche can also accelerate charged particles throughout the structure.
Many other stars exhibit flares, and I will briefly describe recent work on modelling radio emission in flares in young stars (T Tauri stars). In particular, the enhanced radio luminosity of these stars relative to scaling laws for the Sun and other Main Sequence stars will be discussed.

With warmest regards,
Marianna Korsos, Chris Nelson, and Jiajia Liu
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For information about previous talks, please visit the UK-SOSS website: https://solarphysics.aber.ac.uk/uk-soss.php
You can subscribe to the UK-SOSS newsletter on this link:
https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=UK-SOSS&A=1
The UK-SOSS is supported by Aberystwyth University and Queen’s University Green Fund… continue to the full article

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Speaker: Prof. Silvia Dalla (University of Central Lancashire)
Title: Solar Energetic Particles: origins and propagation
Zoom link: https://zoom.us/j/95338171418
Meeting ID: 953 3817 1418

Abstract:
Solar Energetic Particles (SEPs) are ions and electrons detected in interplanetary space in association with flare and coronal mass ejection events. By propagating through the solar wind’s magnetic field, these particles may reach near-Earth locations, where they pose a radiation risk to humans in space and satellite hardware. This talk will review our understanding of the origin and transport of SEPs, based on a large body of data gathered by spacecraft detectors and on theoretical models. It will focus on recent results of test particle simulations, which show that accurate modelling of SEP propagation requires a 3D approach, due to guiding centre drifts and magnetic field line meandering.

With warmest regards,
Jiajia Liu, Marianna Korsos and Chris Nelson
—————————————————————————————————–
For information about previous talks, please visit the UK-SOSS website: https://solarphysics.aber.ac.uk/uk-soss.php
You can subscribe to the UK-SOSS newsletter on this link:
https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=UK-SOSS&A=1
The UK-SOSS is supported by Aberystwyth University and Queen’s University Green Fund

https://solarphysics.aber.ac.uk/uk-soss.php… continue to the full article

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The next seminar will be held on: 17th September, 2020, 10:00 am (UK time)

Speaker: Prof. William Chaplin (University of Birmingham)
Title: Probing the Solar Cycle with BiSON: The Solar-Stellar Connection
Zoom link: https://zoom.us/j/95338171418
Meeting ID: 953 3817 1418

Abstract:

In this talk I will review how we are utilizing helioseismic observations made by the Birmingham Solar-Oscillations Network (BiSON) to provide unique inferences on the solar activity cycle, using its unprecedented long timebase dataset that is now extending into a fifth cycle. I will also discuss how we are using these data together with asteroseismic data, collected on other Sun-like stars by the NASA Kepler Mission, to provide a broader perspective on stellar activity and dynamo action in main-sequence stars.

With warmest regards,

Marianna Korsos, Chris Nelson, and JiaJia Liu

—————————————————————————————————–
For the previous talk, please visit the UK-SOSS website: https://solarphysics.aber.ac.uk/uk-soss.php

You can subscribe to the UK-SOSS newsletter on this link:
https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=UK-SOSS&A=1

The UK-SOSS is supported by Aberystwyth University and Queen’s University Green Fund
————————————-… continue to the full article

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After the successful trial period of UK-SOSS, we will continue the seminar series once a month.

We have agreed and arranged with the ESPOS (European Solar Physics Online Seminar) organisers that UK-SOSS and ESPOS seminars will be not held in the same week.

The next seminar will be held on: 17th September, 2020, 10:00 am (UK time)

Speaker: Prof. William Chaplin (University of Birmingham)
Title: Probing the Solar Cycle with BiSON: The Solar-Stellar Connection
Zoom link: https://zoom.us/j/95338171418
Meeting ID: 953 3817 1418

Abstract:

In this talk I will review how we are utilizing helioseismic observations made by the Birmingham Solar-Oscillations Network (BiSON) to provide unique inferences on the solar activity cycle, using its unprecedented long timebase dataset that is now extending into a fifth cycle. I will also discuss how we are using these data together with asteroseismic data, collected on other Sun-like stars by the NASA Kepler Mission, to provide a broader perspective on stellar activity and dynamo action in main-sequence stars.

With warmest regards,

Marianna Korsos, Chris Nelson, and JiaJia Liu

—————————————————————————————————–
You can subscribe to the UK-SOSS newsletter on this link:
https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=UK-SOSS&A=1

The UK-SOSS is supported by Aberystwyth University and Queen’s University Green Fund
————————————-… continue to the full article

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Dear Colleagues,

The UKSP Council will hold a virtual UKSP Business Meeting at 14:00-15:00 on the 13th July.

Further details regarding the agenda and the meeting link will be provided next week.

Kind regards,
UKSP Council… continue to the full article

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We are happy to announce that we upgraded the UK-SOSS zoom licence for a large meeting option (500 participants). Please find the new zoom link and the meeting-ID below.

The 3rd seminar will be held on: 19th of May, 2020, 11:00 am (UK time)
Speaker: Prof. Anthony Yeates (Durham University)
Title: Where do solar eruptions come from?
Zoom link: https://zoom.us/j/95338171418
Meeting ID 953 3817 1418

Abstract:
An oft-quoted idea in solar physics is that coronal mass ejections are, fundamentally, the Sun’s way of shedding the magnetic helicity that is continually generated by its interior flows. In this talk, I will show how models are helping to give us a handle on the build up of magnetic helicity in the corona (the Sun’s lower atmosphere): how much is injected, where it collects, and how it is ultimately ejected. This requires time-evolving coronal magnetic field models as well as new tools for analysing the distribution of magnetic helicity.

———–
The 4th seminar will be held on: 16th of June, 2020, 11:00 am (UK time)
Speaker: Prof Mitchell Berger (University of Exeter)
Title: Magnetic helicity: decompositions and methods of localization
Zoom link: https://zoom.us/j/95338171418
Meeting ID 953 3817 1418

Abstract:
Magnetic helicity is an ideal MHD invariant; it measures geometric and topological properties of a magnetic field. The talk will begin by reviewing helicity and its mathematical properties. It can be decomposed in several ways (for example, self and mutual helicity, Fourier spectra, field line helicity, linking, twist, and writhe). The talk will also review methods of measuring the helicity flux, as well as applications in solar and stellar astrophysics.
I will then discuss some new developments in measuring localized concentrations of helicity in a well-defined, gauge invariant manner, using wavelets.

—————————————————————————————————–
You can subscribe to the UK-SOSS newsletter on this link:
https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=UK-SOSS&A=1

The Zoom link is supported by Aberystwyth University and Queen’s University Green Fund

Marianna Korsos, JiaJia Liu and Chris Nelson… continue to the full article

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We are pleased to announce the second and the third UK-based Solar Online Seminar Series – UK-SOSS.

The 2nd seminar will be held on: 21st of April, 2020, 11:00 am (UK time)
Speaker: Prof. Sarah Matthews (University College London)
Title: Probing energy release and transport in explosive events

Abstract: The magnetic field of the corona stores the energy that is released via magnetic reconnection during solar flares and coronal mass ejections (CMEs). Flares with CMEs are often described by the ‘standard’ eruptive flare (CSHKP) model and this offers a conceptual framework in which to investigate the global characteristics of the energy release and transport in the context of the magnetic field configuration. The low plasma beta environment of the corona means the magnetic field plays a central role in the energy transport, and different magnetic field configurations can lead to a variety of outcomes in terms of the evolution of the energy release, the efficiency of the energy transport mechanisms and the locations where the energy is deposited. Despite the often rather good agreement between observations and the ‘standard’ model, many open questions remain particularly in respect to the triggering of the energy release. In this talk I will discuss how multi-wavelength spectroscopy used in tandem with magnetic field information can help shed light on some of these open questions.

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The 3rd seminar will be held on: 19th of May, 2020, 11:00 am (GMT)
Speaker: Prof. Anthony Yeates (Durham University)
Title: Where do solar eruptions come from?

Abstract:
An oft-quoted idea in solar physics is that coronal mass ejections are, fundamentally, the Sun’s way of shedding the magnetic helicity that is continually generated by its interior flows. In this talk, I will show how models are helping to give us a handle on the build up of magnetic helicity in the corona (the Sun’s lower atmosphere): how much is injected, where it collects, and how it is ultimately ejected. This requires time-evolving coronal magnetic field models as well as new tools for analysing the distribution of magnetic helicity.

Best Regards,

Marianna Korsos (University of Aberystwyth), JiaJia Liu (University of Sheffield) and Chris Nelson (Queen’s University Belfast )… continue to the full article

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The first seminar will be held as follows
Time: 11:00am (GMT), 24 March, 2020
Zoom link: https://zoom.us/j/312324744
Speaker: Prof. Ineke De Moortel (University of St Andrews)
Title: Aspects of MHD Wave Heating in the Complex Solar Atmosphere

Abstract: In a series of numerical experiments, we investigate the possible role of MHD waves in the energy and mass cycle in the complex solar corona. Using 3D MHD simulations of transverse, Alfvenic waves, we look at the role of chromospheric evaporation, the complexity of the magnetic field and the power spectrum of the wave driver. We focus on the efficiency of the wave-based heating in our models, in particular whether heating provided by the waves can balance coronal losses and whether proposed wave heating mechanisms are in fact self-consistent.

Best Regards,

Marianna Korsos (University of Aberystwyth), JiaJia Liu (University of Sheffield) and Chris Nelson (Queen’s University Belfast )… continue to the full article

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We are pleased to announce the new UK-based Solar Online Seminar Series – UK-SOSS.

UK-SOSS will be convened and hosted via a zoom link (to be announced in due course) between March and June once a month during the trial period. In this semester, senior colleagues deliver review talks about their research areas to the UKSP community. The review style of talks will differentiate UK-SOSS from ESPOS, thereby providing a complementary value to the UK community.

The first seminar will be held on: 24 March, 2020, 11:00 am (GMT).
The speaker is: Prof. Ineke De Moortel (University of St Andrews).
Title: Aspects of MHD Wave Heating in the Complex Solar Atmosphere

Abstract:
In a series of numerical experiments, we investigate the possible role of MHD waves in the energy and mass cycle in the complex solar corona. Using 3D MHD simulations of transverse, Alfvenic waves, we look at the role of chromospheric evaporation, the complexity of the magnetic field and the power spectrum of the wave driver. We focus on the efficiency of the wave-based heating in our models, in particular whether heating provided by the waves can balance coronal losses and whether proposed wave heating mechanisms are in fact self-consistent.

Marianna Korsos (University of Aberystwyth), JiaJia Liu (University of Sheffield) and Chris Nelson (Queen’s University Belfast )… continue to the full article

Read more