A1S2WP3
From Soteria
Besides its visible light the Sun continously emits a stream of charged particles out of his hot outer atmosphere, the corona, termed solar wind. The Earth's magnetosphere is permanently engulfed by the solar wind. The solar wind plasma emanating from the Sun carries in it the solar magnetic field of its source region in the photosphere and corona, so that its electric field imposed on the Earth's magnetosphere varies with the solar wind properties. Changing solar wind conditions thus lead to varying electric currents in the Earth's magnetosphere. Coronal mass ejections (CMEs) are huge transient ejections of plasma and magnetic fields out of the solar corona which propagate through space through the normal solar wind. When very fast CMEs reach Earth they can have dramatic effects on our modern infrastructure in terms of satellite damages, power outages or disturbance of telecommunication- and navigation-systems. The variable magnetic field of the solar photosphere also causes magnetic reconnection processes, often in association with CMEs, which lead to transient EUV- and X-ray emissions, sometimes even to radiation of gamma-rays. These so called flares impose short-term irregularities of the Earth upper atmosphere. Solar energetic particles (SEPs) with energies up to the GeV range can be emitted sporadically in the process of flares and CMEs. High intensity SEP events are a thread to satellite systems and impose radiation hazards to astronauts.
The goals of WP3 "Chromosphere and Corona" are to foster our understanding on the origin, evolution and geo-space impact of
solar transient processes, especially flares, CMEs and SEP events.
Participating Institutions are KU Leuven, UNIGRAZ, ROB, OBSPARIS, SRC-PAS, HVAR, LPI and UGOE as WP lead.
The dedicated scientific questions addressed in the scientific studies of WP3 are:
- To better understand the physical processes through which energy is released in flares, CMEs and SEP events through
analyses of state of the art data from current multipoint positioned spacecraft (STEREO, SOHO, CORONAS-Photon, ACE, Proba2),
modelling of these processes and simulations. The report on the energy release in flares and CMEs and their geo-space
impacts summarises the achievements of the joint studies within WP3 as D3.1 dedicated to Tasks 3.5 and 3.2.
- To better understand the initiation of flares, CMEs and SEP events in their solar source regions based on space- and ground-based multi-wavelengths observations including new instrumentations on CORONAS-F (TESIS, SphinX) and Proba 2 (SWAP, LYRA) and refinement of ground-based H-alpha and CaII-K and NaD1 observations, including a flare patrol and special observing programs (Tasks 3.1, 3.2).
- To achieve new insights into the 3D structure of CMEs and their interplanetary evolution through multipoint space observations from
STEREO and SOHO (Task 3.4).
- To achieve new understandings on the effects of the studied eruptive processes on the global solar atmosphere (EUV waves, Moreton waves, interconnecting loops, multiple eruptions, coronal and photospheric magnetic field restructurings, coronal heating).
- To achieve state of the art data-driven numerical MHD-modelling of CME acceleration and kinematics and by taking into account their pre-eruptive phases to facilitate their possible prediction (Task 3.3) in conjunction based on the results of the observ ing programs.
- To disseminate the new data sets as online archives (H-alpha and CaK data, SphinX and TESIS databases, STEREO database, Proba 2 database).
