Bingert, Sven

[["dc.bibliographiccitation.firstpage","261"],["dc.bibliographiccitation.issue","1/2"],["dc.bibliographiccitation.journal","Geophysical & Astrophysical Fluid Dynamics"],["dc.bibliographiccitation.lastpage","281"],["dc.bibliographiccitation.volume","114"],["dc.contributor.author","Warnecke, Jörn"],["dc.contributor.author","Bingert, Sven"],["dc.date.accessioned","2018-12-10T11:05:17Z"],["dc.date.available","2018-12-10T11:05:17Z"],["dc.date.issued","2019"],["dc.description.abstract","The hot loop structures in the solar corona can be well modeled by three dimensional magnetohydrodynamic simulations, where the corona is heated by field line braiding driven at the photosphere. To be able to reproduced the emission comparable to observations, one has to use realistic values for the Spitzer heat conductivity, which puts a large constrain on the time step of these simulations and therefore make them computationally expensive. Here, we present a non-Fourier description of the heat flux evolution, which allow us to speed up the simulations significantly. Together with the semi-relativistic Boris correction, we are able to limit the time step constrain of the Alfv'en speed and speed up the simulations even further. We discuss the implementation of these two methods to the \\PC and present their implications on the time step, and the temperature structures, the ohmic heating rate and the emission in simulations of the solar corona. We find that with the use of the non-Fourier description of the heat flux evolution and the Boris correction, we can increase the time step of the simulation significantly without moving far away from the reference solution. However, for too low values of the Alfv'en speed limit, the simulation moves away from the reference solution und produces much higher temperatures and stronger emission structures."],["dc.identifier.doi","10.1080/03091929.2019.1670173"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/57078"],["dc.language.iso","en"],["dc.notes.status","zu prüfen"],["dc.title","Non-Fourier description of heat flux evolution in 3D MHD simulations of the solar corona"],["dc.type","journal_article"],["dc.type.internalPublication","no"],["dspace.entity.type","Publication"],["local.message.claim","2019-03-21T08:55:37.804+0000|||rp27505|||submit_approve|||dc_contributor_author|||None"]]

[["dc.bibliographiccitation.artnumber","A30"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.volume","550"],["dc.contributor.author","Bingert, Sven"],["dc.contributor.author","Hardi, Peter"],["dc.date.accessioned","2019-12-13T08:29:03Z"],["dc.date.available","2019-12-13T08:29:03Z"],["dc.date.issued","2012"],["dc.description.abstract","Context. We investigate the statistics of the spatial and temporal distribution of the coronal heating in a three-dimensional magneto- hydrodynamical (3D MHD) model. The model describes the temporal evolution of the corona above an observed active region. The model is driven by photospheric granular motions which braid the magnetic field lines. This induces currents and their dissipation heats the plasma. We evaluate the transient heating as subsequent heating events and analyze their statistics. The results are then interpreted in the context of observed flare statistics and coronal heating mechanisms. Methods. To conduct the numerical experiment we use a high order finite difference code which solves the partial differential equations for the conservation of mass, the momentum and energy balance, and the induction equation. The energy balance includes the Spitzer heat conduction and the optical thin radiative loss in the corona. Results. The temporal and spatial distribution of the Ohmic heating in the 3D MHD model follow a power law and can therefore be explained by system in a self-organized critical state. The slopes of the power law are similar to the results based on flare observations. We find that the corona is heated foot point dominated and the coronal heating is dominated by events called nanoflares with energies on the order of 1017 J."],["dc.identifier.arxiv","1211.6417v2"],["dc.identifier.doi","10.1051/0004-6361/201220469"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/62749"],["dc.language.iso","en"],["dc.relation.issn","0004-6361"],["dc.relation.issn","1432-0746"],["dc.title","Nanoflare statistics in an active region 3D MHD coronal model"],["dc.type","journal_article"],["dc.type.internalPublication","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","33"],["dc.bibliographiccitation.lastpage","38"],["dc.contributor.author","Schmitt, Oliver"],["dc.contributor.author","Majchrzak, Tim A."],["dc.contributor.author","Bingert, Sven"],["dc.date.accessioned","2019-12-13T08:14:43Z"],["dc.date.available","2019-12-13T08:14:43Z"],["dc.date.issued","2015"],["dc.description.abstract","The continuation of Persistent Identifier Infrastructures is crucial when next-generation Internet architectures based on Information-Centric Networking (ICN) arise. When moving to ICN, we must ensure the resolution of Persistent Identifiers (PID), such as the billions of Digital Object Identifiers (DOI) used today, to provide continued access to scientific literature and research data. It provides the base for the necessary transformations in the Handle System architecture and protocol for running a PID system on the Named Data Networking (NDN) architecture, which is a recent incarnation of ICN. Furthermore, it examines the PID-specific resolution access patterns, investigates the expected performance for the PID stack in NDN, and shows that the NDN architecture can hardly outperform classic host-to-host network connectivity with use cases provided by the Handle System for resolving PIDs."],["dc.identifier.doi","10.1109/NAS.2015.7255207"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/62745"],["dc.language.iso","en"],["dc.publisher","IEEE"],["dc.relation.conference","2015 IEEE International Conference on Networking, Architecture and Storage (NAS)"],["dc.relation.eventend","2015-08-07"],["dc.relation.eventlocation","Boston, MA, USA"],["dc.relation.eventstart","2015-08-06"],["dc.relation.isbn","978-1-4673-7891-8"],["dc.relation.ispartof","2015 IEEE International Conference on Networking, Architecture and Storage (NAS)"],["dc.relation.orgunit","Gesellschaft für wissenschaftliche Datenverarbeitung"],["dc.title","Experimental realization of a Persistent Identifier Infrastructure stack for Named Data Networking"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","A53"],["dc.bibliographiccitation.journal","Astronomy & Astrophysics"],["dc.bibliographiccitation.volume","607"],["dc.contributor.author","Warnecke, Jörn"],["dc.contributor.author","Chen, Feng"],["dc.contributor.author","Bingert, Sven"],["dc.contributor.author","Peter, Hardi"],["dc.date.accessioned","2018-03-23T09:26:09Z"],["dc.date.available","2018-03-23T09:26:09Z"],["dc.date.issued","2016"],["dc.description.abstract","Aims. We study the magnetic field and current structure associated with a coronal loop. Through this we investigate to what extent the assumptions of a force-free magnetic field break down and where they might be justified. Methods. We analyze a three-dimensional (3D) magnetohydrodynamic (MHD) model of the solar corona in an emerging active region with the focus on the structure of the forming coronal loops. The lower boundary of this simulation is taken from a model of an emerging active region. As a consequence of the emerging magnetic flux and the horizontal motions at the surface a coronal loop forms self-consistently. We investigate the current density along magnetic field lines inside (and outside) this loop and study the magnetic and plasma properties in and around this loop. The loop is defined as the bundle of field lines that coincides with enhanced emission in extreme UV. Results. We find that the total current along the emerging loop changes its sign from being antiparallel to parallel to the magnetic field. This is caused by the inclination of the loop together with the footpoint motion. Around the loop, the currents form a complex non-force-free helical structure. This is directly related to a bipolar current structure at the loop footpoints at the base of the corona and a local reduction of the background magnetic field (i.e., outside the loop) caused by the plasma flow into and along the loop. Furthermore, the locally reduced magnetic pressure in the loop allows the loop to sustain a higher density, which is crucial for the emission in extreme UV. The action of the flow on the magnetic field hosting the loop turns out to also be responsible for the observed squashing of the loop. Conclusions. The complex magnetic field and current system surrounding it can only be modeled in 3D MHD models where the magnetic field has to balance the plasma pressure. A one-dimensional coronal loop model or a force-free extrapolation cannot capture the current system and the complex interaction of the plasma and the magnetic field in the coronal loop, despite the fact that the loop is under low-β conditions."],["dc.identifier.arxiv","1611.06170v3"],["dc.identifier.doi","10.1051/0004-6361/201630095"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/13129"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.relation.orgunit","Gesellschaft für wissenschaftliche Datenverarbeitung"],["dc.title","Current systems of coronal loops in 3D MHD simulations"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","A86"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.volume","589"],["dc.contributor.author","Bourdin, Philippe-A."],["dc.contributor.author","Bingert, Sven"],["dc.contributor.author","Hardi, Peter"],["dc.date.accessioned","2019-12-13T08:11:40Z"],["dc.date.available","2019-12-13T08:11:40Z"],["dc.date.issued","2016"],["dc.description.abstract","Context. The structure and heating of coronal loops are investigated since decades. Established scaling laws relate fundamental quantities like the loop apex temperature, pressure, length, and the coronal heating. Aims. We test such scaling laws against a large-scale 3D MHD model of the Solar corona, which became feasible with nowadays high-performance computing. Methods. We drive an active region simulation a with photospheric observations and found strong similarities to the observed coronal loops in X-rays and EUV wavelength. A 3D reconstruction of stereoscopic observations showed that our model loops have a realistic spatial structure. We compare scaling laws to our model data extracted along an ensemble of field lines. Finally, we fit a new scaling law that represents well hot loops and also cooler structures, which was not possible before only based on observations. Results. Our model data gives some support for scaling laws that were established for hot and EUV-emissive coronal loops. For the RTV scaling law we find an offset to our model data, which can be explained by 1D considerations of a static loop with a constant heat input and conduction. With a fit to our model data we set up a new scaling law for the coronal heat input along magnetic field lines. Conclusions. RTV-like scaling laws were fitted to hot loops and therefore do not predict well the coronal heat input for cooler structures that are hardly observable. The basic differences between 1D and self-consistent 3D modeling account for deviations between our and earlier scaling laws. We also conclude that a heating mechanism by MHD-turbulent dissipation within a braided flux tube would heat the corona stronger than consistent with our model corona."],["dc.identifier.arxiv","1603.05276v2"],["dc.identifier.doi","10.1051/0004-6361/201525840"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/62744"],["dc.language.iso","en"],["dc.relation.issn","0004-6361"],["dc.relation.issn","1432-0746"],["dc.title","Scaling laws of coronal loops compared to a 3D MHD model of an Active Region"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","A104"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.volume","556"],["dc.contributor.author","Peter, H."],["dc.contributor.author","Bingert, Sven"],["dc.contributor.author","Klimchuk, J. A."],["dc.contributor.author","DeForest, C."],["dc.contributor.author","Cirtain, J. W."],["dc.contributor.author","Golub, L."],["dc.contributor.author","Winebarger, A. R."],["dc.contributor.author","Kobayashi, K."],["dc.contributor.author","Korreck, K. E."],["dc.date.accessioned","2019-12-13T08:26:20Z"],["dc.date.available","2019-12-13T08:26:20Z"],["dc.date.issued","2013"],["dc.description.abstract","We will use new data from the High-resolution Coronal Imager (Hi-C) with unprecedented spatial resolution of the solar corona to investigate the structure of coronal loops down to 0.2 arcsec. During a rocket flight Hi-C provided images of the solar corona in a wavelength band around 193 A that is dominated by emission from Fe XII showing plasma at temperatures around 1.5 MK. We analyze part of the Hi-C field-of-view to study the smallest coronal loops observed so far and search for the a possible sub-structuring of larger loops. We find tiny 1.5 MK loop-like structures that we interpret as miniature coronal loops. These have length of the coronal segment above the chromosphere of only about 1 Mm and a thickness of less than 200 km. They could be interpreted as the coronal signature of small flux tubes breaking through the photosphere with a footpoint distance corresponding to the diameter of a cell of granulation. We find loops that are longer than 50 Mm to have a diameter of about 2 arcsec or 1.5 Mm, consistent with previous observations. However, Hi-C really resolves these loops with some 20 pixels across the loop. Even at this greatly improved spatial resolution the large loops seem to have no visible sub-structure. Instead they show a smooth variation in cross-section. The fact that the large coronal loops do not show a sub-structure at the spatial scale of 0.1 arcsec per pixel implies that either the densities and temperatures are smoothly varying across these loops or poses an upper limit on the diameter of strands the loops might be composed of. We estimate that strands that compose the 2 arcsec thick loop would have to be thinner than 15 km. The miniature loops we find for the first time pose a challenge to be properly understood in terms of modeling."],["dc.identifier.arxiv","1306.4685v1"],["dc.identifier.doi","10.1051/0004-6361/201321826"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/62748"],["dc.language.iso","en"],["dc.relation.issn","0004-6361"],["dc.relation.issn","1432-0746"],["dc.title","Structure of solar coronal loops: from miniature to large-scale"],["dc.type","journal_article"],["dc.type.internalPublication","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","15"],["dc.bibliographiccitation.journal","GWDG-Nachrichten"],["dc.bibliographiccitation.lastpage","17"],["dc.bibliographiccitation.volume","8-9/19"],["dc.contributor.author","Bingert, Sven"],["dc.contributor.author","Steilen, Lena"],["dc.date.accessioned","2022-11-28T15:35:32Z"],["dc.date.available","2022-11-28T15:35:32Z"],["dc.date.issued","2019"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/117801"],["dc.relatedmaterial.fulltext","https://www.gwdg.de/documents/20182/27257/GN_8-9-2019_www.pdf"],["dc.relation.orgunit","eResearch Alliance Göttingen"],["dc.title","Data Science Summer School 2019"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","A1"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.volume","548"],["dc.contributor.author","Peter, H."],["dc.contributor.author","Bingert, Sven"],["dc.date.accessioned","2019-12-13T08:31:09Z"],["dc.date.available","2019-12-13T08:31:09Z"],["dc.date.issued","2012"],["dc.description.abstract","The corona of the Sun is dominated by emission from loop-like structures. When observed in X-ray or extreme ultraviolet emission, these million K hot coronal loops show a more or less constant cross section. In this study we show how the interplay of heating, radiative cooling, and heat conduction in an expanding magnetic structure can explain the observed constant cross section. We employ a three-dimensional magnetohydrodynamics (3D MHD) model of the corona. The heating of the coronal plasma is the result of braiding of the magnetic field lines through footpoint motions and subsequent dissipation of the induced currents. From the model we synthesize the coronal emission, which is directly comparable to observations from, e.g., the Atmospheric Imaging Assembly on the Solar Dynamics Observatory (AIA/SDO). We find that the synthesized observation of a coronal loop seen in the 3D data cube does match actually observed loops in count rate and that the cross section is roughly constant, as observed. The magnetic field in the loop is expanding and the plasma density is concentrated in this expanding loop; however, the temperature is not constant perpendicular to the plasma loop. The higher temperature in the upper outer parts of the loop is so high that this part of the loop is outside the contribution function of the respective emission line(s). In effect, the upper part of the plasma loop is not bright and thus the loop actually seen in coronal emission appears to have a constant width. From this we can conclude that the underlying field-line-braiding heating mechanism provides the proper spatial and temporal distribution of the energy input into the corona --- at least on the observable scales."],["dc.identifier.arxiv","1209.0789v1"],["dc.identifier.doi","10.1051/0004-6361/201219473"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/62750"],["dc.language.iso","en"],["dc.relation.issn","0004-6361"],["dc.relation.issn","1432-0746"],["dc.title","Constant cross section of loops in the solar corona"],["dc.type","journal_article"],["dc.type.internalPublication","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.lastpage","5"],["dc.contributor.author","Doan, Triet"],["dc.contributor.author","Bingert, Sven"],["dc.contributor.author","Wiese, Lena"],["dc.contributor.author","Yahyapour, Ramin"],["dc.contributor.editor","Jäschke, Robert"],["dc.contributor.editor","Weidlich, Matthias"],["dc.date.accessioned","2021-10-26T13:12:10Z"],["dc.date.available","2021-10-26T13:12:10Z"],["dc.date.issued","2019"],["dc.identifier.doi","10.15488/9817"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/91394"],["dc.relation.conference","LWDA 2019"],["dc.relation.eventlocation","Berlin"],["dc.relation.eventstart","2019"],["dc.relation.ispartof","Proceedings of the Conference on \"Lernen, Wissen, Daten, Analysen\""],["dc.relation.orgunit","Gesellschaft für wissenschaftliche Datenverarbeitung"],["dc.rights","CC BY 4.0"],["dc.title","A Graph Database for Persistent Identifiers"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","A39"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.volume","554"],["dc.contributor.author","van Wettum, T."],["dc.contributor.author","Bingert, Sven"],["dc.contributor.author","Peter, H."],["dc.date.accessioned","2018-11-07T09:23:51Z"],["dc.date.available","2018-11-07T09:23:51Z"],["dc.date.issued","2013"],["dc.description.abstract","Aims. We investigate the difference in the spatial distribution of the energy input for parameterisations of different mechanisms to heat the corona of the Sun and possible impacts on the coronal emission. Methods. We use a 3D magneto-hydrodynamic (MHD) model of a solar active region as a reference and compare the Ohmic-type heating in this model to parameterisations for alternating current (AC) and direct current (DC) heating models; in particular, we use Alfven wave and MHD turbulence heating. We extract the quantities needed for these two parameterisations from the reference model and investigate the spatial distribution of the heat input in all three cases, globally and along individual field lines. To study differences in the resulting coronal emission, we employ 1D loop models with a prescribed heat input based on the heating rate we extracted along a bundle of field lines. Results. On average, all heating implementations show a rough drop of the heating rate with height. This also holds for individual field lines. While all mechanisms show a concentration of the energy input towards the low parts of the atmosphere, for individual field lines the concentration towards the foot points is much stronger for the DC mechanisms than for the Alfven wave AC case. In contrast, the AC model gives a stronger concentration of the emission towards the foot points. This is because the more homogeneous distribution of the energy input leads to higher coronal temperatures and a more extended transition region. Conclusions. The significant difference in the concentration of the heat input towards the foot points for the AC and DC mechanisms and the pointed difference in the spatial distribution of the coronal emission for these cases show that the two mechanisms should be discriminable by observations. Before drawing final conclusions, these parameterisations should be implemented in new 3D models in a more self-consistent way."],["dc.description.sponsorship","International Max Planck Research School (IMPRS)"],["dc.identifier.doi","10.1051/0004-6361/201321297"],["dc.identifier.isi","000320444200038"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/10569"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/29684"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Edp Sciences S A"],["dc.relation.issn","0004-6361"],["dc.relation.orgunit","Fakultät für Physik"],["dc.title","Parameterisation of coronal heating: spatial distribution and observable consequences"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]