IAUS 327: Fine Structure and Dynamics of the Solar Atmosphere
October 9, 2016
October 14, 2016
Cartagena de Indias,
Santiago Vargas Domínguez
Division E Sun and Heliosphere
|Co-Chairs of SOC:
||Santiago Vargas Domínguez (OAN Universidad Nacional de Colombia)
||Alexander Kosovichev (NJIT)
||Juan Carlos Martínez (SSL/UC Berkeley)
||Louise Harra (MSSL/UCL)
||Cristina Mandrini (CONICET)
|Co-Chairs of LOC:
||Benjamín Calvo Mozo (OAN Universidad Nacional de Colombia)
||Gregorio Portilla (OAN Universidad Nacional de Colombia)
||Juan Manuel Tejero (OAN Universidad Nacional de Colombia)
||Jorge Zuluaga (Universidad de Antioquia)
||Cristian Góez (Universidad Libre)
The solar atmosphere as a system connected by magnetic fields.
Role of small-scale magnetic structures in the dynamics of the solar atmosphere.
Energy and mass transport between the convection zone and the outer solar atmosphere.
Interaction between radiation, convection and magnetic fields in the solar atmosphere.
Magnetic network, hidden magnetism and local dynamo.
Magnetic flux emergence in the solar atmosphere.
Fine structuring in sunspots.
Energy release and explosive events at the finest spatial and temporal scales.
New observational diagnostics: high-resolution imaging spectroscopy and spectropolarimetry.
Theoretical models and numerical simulations.
New capabilities of large solar telescopes.
The scientific goal of this symposium is to discuss recent results on the processes shaping the structure of the solar atmosphere and driving plasma eruptions and explosive events. Activity of the solar atmosphere entails numerous multi-scale processes. State-of-the-art solar instrumentation is revealing the dynamics of the Sun with unprecedented temporal and spatial resolutions. Together with advanced numerical simulations these investigations are making new steps in our understanding of the complex dynamical structure of the solar atmosphere.
Major unsolved problems of astrophysics such as how the solar corona is heated and how the solar wind and heliosphere are powered have their roots in the origin of small-scale magnetic fields constituting the Sun's 'magnetic carpet' in the photosphere and appearing as 'magnetic canopy' in the chromosphere. The questions whether the small-scale fields of the quiet-Sun atmosphere represent remnants of the large-scale field generated by the global dynamo in the deep convection zone or these fields are a product of a near-surface local dynamo and how the energy of the small-scale field is transported through the chromosphere and converted into heat and high-speed flows in the chromosphere-corona transition regions have been topics of hot debates. While the numerical simulations have demonstrated in principle the existence of the local dynamo processes on the Sun their role in the small-scale magnetism of the solar atmosphere remains unclear. Recent discoveries from space missions, rocket experiments, and large-ground based telescopes of fine-scale magnetic loops result in the paradigm change in our understanding of the structure, energetics and dynamics of the solar atmosphere, transition region and corona. In the new picture emerging from the observations and numerical simulations the solar atmosphere appears as highly dynamical multi-scale conglomerate of interacting magnetic loops, magnetized vortex tubes and jets. The mean quiet-Sun field strength is only few Gauss, but locally in the small-scale structures it can reach the kilogauss strength dramatically affecting thermodynamic and dynamical properties of the photospheric and chromospheric plasma. In addition, substantial progress has been made in studying the fine structure of sunspots and active regions. The high-resolution observations reveal the sunspot dynamics in unprecedented details, and raised new questions about the role of the fine structuring in the formation and stability of large-scale magnetic structures. The new observations demonstrate that the atmospheric structure and dynamics of the quiet and active Sun are considerably more complicated than the traditional spectroscopic models.
The understanding of the fine structure and dynamics of the solar atmosphere requires a considerable coordinated effort of observers, theorists and experts in realistic numerical simulations. The proposed symposium is very timely and important. It will make an important step in the big international effort for our understanding of the solar atmosphere with large telescopes and detailed modeling. The Symposium will provide a forum for discussion of the recent advances, and a platform for developing new coordinated observing and theoretical programs. This Symposium will be of great interest also for the IAU Divisions studying stellar atmospheres, starspots, exoplanetary systems, and developing advanced observational techniques and theoretical models.