Dear Colleagues,
The Coronal Loops Workshop series, inaugurated in Paris (2002) with the most
recent Workshop in Palermo (2017), has been tremendously successful in
bringing together researchers from all over the world to discuss current
problems related to the physics of closed magnetic structures in the solar
corona, and to present their progress toward solving them. The Workshops
have also provided an excellent venue for young researchers to participate
in discussions and to showcase their work.
The Steering Committee for the Coronal Loops Workshops is responsible for
soliciting and selecting Workshop proposals, and assisting / advising each
Scientific Organizing Committee in choosing a topical, over-arching theme
and setting an agenda and goals for their Workshop.
The current members of the Steering Committee are: Steve Bradshaw [Chair];
Philippa Browning; Ineke De Moortel; Giulio Del Zanna; Viggo Hansteen;
Susanna Parenti; Paola Testa; Ignacio Ugarte-Urra; Nicholeen Viall.
Three members of the Steering Committee (Susanna Parenti, Ignacio
Ugarte-Urra, and Nicholeen Viall) have reached the end of their 6 year
terms. Since they were elected in 2012 they have been involved in the
organization of 3 Loops Workshops (Loops VI - VIII, not forgetting that
Inaki also Chaired Loops V) and the Loops community owes them a great deal
of thanks and appreciation for their tremendously hard work on our behalf.
It is now time to elect 3 new members of the Steering Committee. We are
soliciting nominations and self-nominations, the latter are particularly
encouraged, to help ensure a diverse pool of candidates to represent the
interests of our community, for scientists who are active in the broad field
of the physics of closed magnetic structures in the solar corona, to serve
on the Coronal Loops Workshops Steering Committee for a 6 year term.
Please submit your nominations and self-nominations to Steve Bradshaw
(Steering Committee Chair: <mailto:stephen.bradshaw@rice.edu>
stephen.bradshaw(a)rice.edu) no later than Monday April 30th. The current
members of the Steering Committee will vote per the Bylaws and the
newly-elected members will be duly contacted and announced directly
thereafter.
With best wishes,
Steve Bradshaw
(on behalf of the Coronal Loops Workshops Steering Committee)
Dr. Stephen J. Bradshaw
(Associate Professor of Physics and Astronomy)
Department of Physics and Astronomy (MS 108)
Rice University,
6100 Main Street,
Houston,
TX 77005,
USA.
Tel: +1 713 348 4045
Email: <mailto:stephen.bradshaw@rice.edu> stephen.bradshaw(a)rice.edu
Web: solar.rice.edu
Dear all,
The paper on the simulations of thermal nonequilibrium I presented during the last loop workshop was published last month in ApJ.
For those of you interested, the paper can be found here:
http://adsabs.harvard.edu/abs/2018ApJ...855...52F
On the Occurrence of Thermal Nonequilibrium in Coronal Loops
Authors: Froment, C.; Auchère, F.; Mikić, Z.; Aulanier, G.; Bocchialini, K.; Buchlin, E.; Solomon, J.; Soubrié, E.
Abstract: Long-period EUV pulsations, recently discovered to be common in active regions, are understood to be the coronal manifestation of thermal nonequilibrium (TNE). The active regions previously studied with EIT/Solar and Heliospheric Observatory and AIA/SDO indicated that long-period intensity pulsations are localized in only one or two loop bundles. The basic idea of this study is to understand why. For this purpose, we tested the response of different loop systems, using different magnetic configurations, to different stratifications and strengths of the heating. We present an extensive parameter-space study using 1D hydrodynamic simulations (1020 in total) and conclude that the occurrence of TNE requires specific combinations of parameters. Our study shows that the TNE cycles are confined to specific ranges in parameter space. This naturally explains why only some loops undergo constant periodic pulsations over several days: since the loop geometry and the heating properties generally vary from one loop to another in an active region, only the ones in which these parameters are compatible exhibit TNE cycles. Furthermore, these parameters (heating and geometry) are likely to vary significantly over the duration of a cycle, which potentially limits the possibilities of periodic behavior. This study also confirms that long-period intensity pulsations and coronal rain are two aspects of the same phenomenon: both phenomena can occur for similar heating conditions and can appear simultaneously in the simulations.
Cheers,
Clara