A1D3.3
From Soteria
Name: Initiation of flares and CMEs
Lead Beneficiary: KU Leuven
Beneficiaries involved: UNIGRAZ, ROB, OBS Paris, SRC-PAS, UGOE, Hvar, LPI
Due Date: 24 months
Goal
Major concern of D3.3 is research of the initiation of flares and CMEs. We aim at improving the understanding of physical mechanisms of energy release in the photospheric and low coronal source-regions, which lead to CMEs and flares. The interrelationships of the flares and CMEs are invesigated, as well as the interaction of CMEs with the global corona.
Progress so far
At KU Leuven homologous CMEs are found to be obtained from a breakout configuration by increasing the shear region to just outside the central arcade. More realistic Solarmax scenarios with multiple streamers involved is modelled, where the interaction of a CME with another streamer can produce secondary eruptions. KU Leuven participated at the Event study workshop in Hvar, September 2009, where the discussion of progress in the currently developed projects took place, and the joint research of UNIGRAZ (collaboration with D3.4) the CME modelling of KU Leuven are planned. At the meeting in ROB, June 2009, possible collaboration between KU Leuven and LPI on modeling chrompspgeric structures was discussed (collaboration with D3.1). Furthermore, at KU Leuven new numerical strategies are set-up for studying the cross-scale dynamics of space and solar plasma. Access to the SPENVIS online system is acquired and its use is studied, in order to utilize it for investigating the effect of radiation on satellites.
At Hvar Observatory multi-wavelength observations of the acceleration phase of 18 CMEs were analyzed. The study of relative kinematics of the CME leading edge and the associated eruptive prominence showed that in 75% cases they are synchronized. The results are presented in Maricic et al, Relative kinematics of the leading edge and the prominence in CME, which is published in SoPhy. Analitical MHD model for studying the formation of the coronal shock-wave, after an impulsive source-region expansion is developed. It is used for studying the propagation of the shock-wave through a decreasing Alfven-velocity environment. In the further step, a numerical study in collaboration of HVAR and C. Jacobs from KU Leuven is foreseen.
The SRC-PAS team has collected and archived the data from the SphinX spectrophotometer, aboard CORONAS-Photon. During first ~7 months of active operation the instrument collected ~35 GB of data, including small flares on March 26th and 4-6 July, 2009. The data analysis of 30 Aug. 2002 and 14 Nov. 2002 flares is in progress. Results of complex analysis of selected flares including HD simulations of interaction between the non-thermal and thermal plasma components have been presented in two papers, A&A 500, 901 and ApJ Letters accepted. Joint analysis of RESIK, GOES, SphinX and RHESSI was performed in order to study flare and quiet solar plasma parameters. The TRACE point spread function has been theoretically modeled for all EUV filters. Related algorithms have been written and made publicly accessible.
At SRC-PAS on line SphinX flare catalogue is created, containing already ~600 events. SphinX metadata are in preparation and SphinX sowtware is in development. Sphinx data archive and www catalog is being maintained and updated. TRACE data and PSF analysis is performed and the data of multispacecraft observations of 30 Aug. 2002 flare event is being reduced. Furthermore, the orbital algorithms for the Coronas-Photon Mission are developed and updated. Automation of SphinX in-orbit operation is performed. On-line reformatting of SphinX telemetry data stream and respective algorithms refinement is in progress and the control of the on-board SphinX computer. Analysis of thermal environment within the SphinX instrument during early operations is done and instrument health control is performed. Laboratory simulation of SphinX electronics behavior under harsh thermal environment conditions are carried out. Additional laboratory measurements of the SophinX EUV filter transmission is measured. Studies of dead-layer for SphinX detectors are performed. The SphinX sensors are calibrated to temperature response. CORONAS-Photon orbital elements database is updated.
Furthermore, at SRC-PAS HD plasma response to heating through non-thermal beams using NRL HD codes is modelled and compared with observations from GOES, SXT & RHESSI. The results are presented in two papers: R. Falewicz P. Rudawy and M. Siarkowski, Relationship between non-thermal electron energy spectra and GOES class, 2009 A&A 500,901 and M. Siarkowski R. Falewicz and P. Rudawy, accepted for publication in ApJ Letters (http://arxiv.org/abs/0910.0751), Plasma heating in the very early phase of solar flares. RESIK data are reduced and Multitemperature Analysis of 14 Nov 2002 flare performed. The results are presented in B. Sylwester, J. Sylwester, K.J.H. Phillips, submitted to A&A and K.J.H. Phillips, J. Sylvester, B. Sylvester, The solar X-ray continuum measured by RESIK, submitted to ApJ.
At UNIGRAZ three selected flare events were analyzed with respect to the flare/CME feedback relation combining STEREO (EUVI, COR1) and RHESSI HXR data. The results show an almost synchronized behavior between the flare energy release and CME acceleration phase. In a next step the spectral parameters from RHESSI for each event were studied in more detail. The amplitude of the power-law fit as well as the spectral slope seem to be positively correlated with the CME acceleration. These results support the "standard" flare/CME
model which is characterized by a feed-back relationship between the
large-scale CME acceleration process and the reconnection in the
associated flare.
A paper in collaboration with Bojan Vrsnak from Hvar Observatory is submitted and under revision (ApJ).
At LPI the TESIS EUV telescope/spectroheliograph succesively operates onboard the CORONAS-Photon satellite since the launch in January, 2009. In spite of very low solar activity during the period of February-October 2009, several flares and giant prominence eruptions have been observed. The data are collected in the TESIS database and analyzed. In addition, new methods for modeling of the hot coronal plasma structures with temperatures log T(K) = 6.0 -7.3 observed in Mg XII monochromatic images have been developed. The results of simulation agree well with the observational data of the SPIRIT experiment onboard CORONAS-F. Two publications are in preparation.
At OBS Paris the pre-eruption filament evolution and activity for the 19 May 2007 CME (from the SOTERIA event list) was analyzed. The filament, which erupted in the CME was formed over two days by merging of an active-region and a quiescent filaments. Mergence was achieved through several episodes of magnetic reconnection. The eruption itself was analyzed by using data from the twin STEREO spacecraft. The 3-D reconstruction of the eruption shows that the active-region part of the filament erupted with greater speed than the quiescent part, making the eruption asymmetric. Two papers have been submitted to Solar Physics, one is published in May 2009 in the special STEREO issue, the other is in press.
Furthermore, at OBS Paris the mechanisms which yield the formation and eruption of a coronal magnetic flux rope in the flux-cancellation model for CMEs were studied, by performing a 3D zero beta MHD simulation. It is found that photospheric flux-cancellation and tether-cutting coronal reconnection are key mechanisms for the formation and slow rise of a flux rope, but do not trigger its eruption. The flux rope erupts in the simulation only if these mechanisms lift the rope to a height at which the ambient potential field drops sufficiently fast for the ideal MHD torus instability to set in, which then triggers the eruption. A manuscript of this work has been submitted to ApJ.
At UGOE more than 100 CMEs have been identified in STEREO data since the launch. For these events the low coronal and photospheric source regions are searched in STEREO/SECCHI/EUVI, SOHO/EIT, and SOHO/MDI observations and associated flare activity is recognized. These events are further studied to analyze the kinematics of CMEs and their effects/interactions on/with the ambient corona. The analysis also addresses the question whether CMEs also occur on small scales.
In ROB the analytical model of a reconnecting current sheet based on Dan Seaton's dissertation research is being developed, due to the absence of data from PROBA2 (now scheduled for launch in Nov. '09). This model is useful in developing understanding of the reconnection mechanism that is responsible for converting stored magnetic energy into heat and kinetic energy during solar eruptions. It makes several specific predictions about the properties of reconnecting current sheets during flares and CMEs that may be observable using SWAP and other instruments such as TESIS. Observing routines based on these predictions for use after the launch of the PROBA2 are developed.
List of the people involved in this deliverable: KU Leuven - Giovanni Lapenta, Lapo Bettarini, Alexander Soenen, Francesco Zuccarello and Stefaan Poedts; Hvar - Bojan Vrsnak, Tomislav Zic and non-Soteria member Darije Maricic; SRC-PAS - Jaroslaw Bakala, Szymon Gburek, Anna Kepa, Zbigniew Kordylewski, Miroslaw Kowalinski, Piotr Podgorski, Marek Siarkowski, Barbara Sylwester, Janusz Sylwester, Witold Trzebinski and S. Plocieniak; UNIGRAZ - Manuela Temmer and Astrid Veronig; LPI - Vladimir Slemzin, Sergey Kuzin, Andrey Pertsov, Alexander Ignatiev, Alexander Urnov and Farid Goryaev; OBS Paris – L. van Driel-Gesztelyi, G. Aulanier, T. Török, P. Démoulin and non-SOTERIA member E.E. DeLuca; UGOE - Volker Bothmer, Bin Gui, Giuseppe Nisticò, Gaetano Zimbardo, Spiros Patsourakos and Ansgar Reiners; ROB - Dan Seaton.
