Prof.
Giovanni Lapenta
(KU-Leuven, Dept. for plasma astrophysics, Belgium)
09/11/2015, 10:00
Invited Key Topic Presentation
Space exploration is no gala dinner. Space is full of threats for humans and for their technology. Radiation from the Sun and form the Cosmos, magnetic storms, sudden emission of energetic particles are examples of the fascinating phenomena that besides being of great scientific interest are also a grave danger.
Modeling these processes is a grand challenge that modern scientific computing...
Dr
Jens Pomoell
(University of Helsinki)
09/11/2015, 10:45
In this work, we present the first results of the new physics-based forecasting-targeted inner heliosphere model Euhforia (‘European heliospheric forecasting information asset’) that we are developing.
Euhforia consists of a coronal model and a magnetohydrodynamic (MHD) heliosphere model with CMEs. The aim of the baseline coronal model is to produce realistic plasma conditions at the...
Dr
Andrei Zhukov
(Royal Observatory of Belgium)
09/11/2015, 12:00
Real-time operational space weather forecasting is still a difficult task that requires specific observational inputs and modeling that are discussed in this presentation, with an emphasis on solar and interplanetary weather. The use of observational data to produce reliable predictions requires development of physical models and empirical/statistical methods. Scientific basis of space weather...
Prof.
Giovanni Lapenta
(KU-Leuven, Dept. for plasma astrophysics, Belgium)
09/11/2015, 14:30
Data assimilation techniques are a way to obtain a better estimate of the state of a system by combining modelling (i.e., simulations) and measures of relevant quantities. Let us assume that an evolution law for the system is known and that observations of the system are available. A transfer matrix which maps the state to the observations is also known. Then, it is possible to obtain an ‘a...
Dr
Dhrubaditya MITRA
(NORDITA (Nordic Institute of Theoretical Physics), Stockholm)
09/11/2015, 15:00
Accurate knowledge of time-variation in meridional flow-speed and profile is crucial for estimating a solar cycle's features, which are ultimately responsible for causing space climate variations. However, no consensus has been reached yet about the Sun's meridional circulation pattern observations and theories. By implementing an Ensemble Kalman Filter (EnKF) data assimilation in a...
Dr
Alessandro Bemporad
(INAF-Turin Astrophysical Observatory)
09/11/2015, 16:00
The knowledge of coronal magnetic fields is of fundamental importance in order to understand the evolution of the main drivers of geomagnetic storms: solar wind and coronal mass ejections. Nevertheless, measurements of these fields are very difficult. Recently it has been shown that remote sensing UV and WL observations of shocks propagating into the corona and associated with major solar...
Dr
Klaus Galsgaard
(NBI)
10/11/2015, 09:30
To reproduce the dynamical evolution of active regions in the Sun, it is required to
use more realistic models. To a lowest order the magnetic field may be represented
by simple field extrapolations based on the photospheric magnetic field distribution.
This has been standard for many years. To reproduce the evolution of the magnetic
field, a correct representation of the boundary...
Fernando Moreno-Insertis
(Instituto de Astrofisica de Canarias)
10/11/2015, 10:00
Although studied for a few decades now, the collimated plasma ejections detected in the EUV and X-Ray spectral ranges still contain many unsolved puzzles concerning the underlying coronal structures and the basic physical processes at work in them. The initial 2D numerical models of the 1990s provided basic physical insight in spite of the low spatial resolution and unrealistic values for the...
Dr
Emilia Kilpua
(University of Helsinki)
10/11/2015, 10:30
In this presentation I will discuss the key solar wind parameters in Coronal Mass Ejections (CMEs) that determine their ability to disturb the near-Earth space environment. The emphasis is one those factors that are needed from solar modelling to improve the accuracy of long-lead time targeted space weather forecasts. The particularly important for determining the timing, magnitude and...
Prof.
Rami Vainio
(Department of Physics and Astronomy, University of Turku, Finland)
10/11/2015, 11:30
We present a study of particle acceleration at travelling coronal / interplanetary shocks. We use three simulation codes for the purpose: (1) the global CSA Monte Carlo simulation code; (2) the local SOLPACS Monte Carlo simulation code, and (3) the Vlasiator hybrid-Vlasov code, initially developed for global magnetospheric simulations, but used here for local simulations of interplanetary...
Prof.
Joerg Buechner
(Max-Planck-Institute for Solar System Reserach)
10/11/2015, 12:15
We compare observed CME eruptions with the results of GOEMHD3 numerical simulations of the Solar atmosphere based on data obtained by observations of the Sun and taking into account cross-scale coupling effects of turbulence. We compare our findings with those of current laboratory eruption experiments carried out at the Princeton Plasma Physics Laboratory (MRX).
Dr
Jaeyoung Park
(Energy Matter Conversion Corporation)
10/11/2015, 14:30
Invited Key Topic Presentation
Nuclear fusion power is considered the ultimate energy source because of its nearly inexhaustible supply of cheap fuels, intrinsic safety, zero emissions and lack of long-lived radioactive waste. Despite tremendous progress in science and technology of fusion reactors, the general consensus has been, and still is, “fusion is always 20 years away”. In this talk, I will introduce the Polywell...
Dr
Christoph Koehn
(DTU Space, Lyngby, Denmark)
11/11/2015, 09:30
For two decades thunderstorms have been observed to emit terrestrial gamma-ray flashes (TGFs), flashes of photons with single quantum energies of up to 40 MeV, as well as positron and neutron beams.
TGFs, the only known natural events with energies of several tens of MeV, are produced through the Bremsstrahlung process by high-energy electrons which are accelerated in the vicinity of...
Mr
Mordechai Butrashvily
(Tel-Aviv University)
11/11/2015, 10:00
Realistic simulations in plasma physics employ a large number of particles, usually beyond existing computer memory limits. To solve the problem, Particle-In-Cell (PIC) codes use the K-means clustering method to obtain a compact representation for so many particles by introducing mega-particles with "weight". However, the computational complexity of k-means is NP-hard to solve. Simpler...
Fabien Widmer
(Max Planck Institute for Solar System Research)
11/11/2015, 11:00
Magnetic reconnection requires, at least locally, a non-ideal plasma response. In collisionless space and astrophysical plasmas, turbulence could permit this instead of the too rare binary collisions. The possible influence of turbulence on the reconnection rate is investigated in the framework of a single fluid compressible MHD approach through simulations of a double Harris and force free...
Dr
Vyacheslav Olshevsky
(KU Leuven)
11/11/2015, 11:30
We present the first ever systematic attempt to study magnetic null points and the associated magnetic energy conversion in kinetic Particle-in-Cell simulations of various plasma configurations. We address three-dimensional simulations performed with the semi-implicit kinetic electromagnetic code iPic3D in different setups: variations of Harris current sheet, dipolar and quadrupolar...
Dr
Paolo Pagano
(University of St Andrews)
11/11/2015, 14:00
Magnetic flux ropes ejections are considered a progenitor of Coronal Mass Ejections (CMEs) and their occurrence usually follows a long lasting equilibrium in the solar corona. Magnetic flux ropes form in the solar corona due to the evolution the coronal magnetic field driven by photospheric motions and flux emergence events and when magnetic flux ropes become unstable their ejection may turn...
Mr
Mordechai Butrashvily
(Tel-Aviv University)
11/11/2015, 14:30
Segmentation is a process used to identify objects within an image, including their boundary and other properties. Therefore, it serves as a key component in many image processing workflows, including scientific observation purposes. Most traditional methods use gradient information to extract object features and perform segmentation. However, there are drawbacks with such methods as they fail...
