Now showing items 1-13 of 13

    • Bombs and flares at the surface and lower atmosphere of the Sun 

      Hansteen, V. H.; Archontis, V.; Pereira, T. M. D.; Carlsson, M.; Rouppe van der Voort, L.; Leenaarts, J. (2017-04-10) - Journal article
      A spectacular manifestation of solar activity is the appearance of transient brightenings in the far wings of the Hα line, known as Ellerman bombs (EBs). Recent observations obtained by the Interface Region Imaging ...
    • The dependence of coronal loop heating on the characteristics of slow photospheric motions 

      Ritchie, M. L.; Wilmot-Smith, A. L.; Hornig, G. (2016-06-06) - Journal article
      The Parker hypothesis assumes that heating of coronal loops occurs due to reconnection, induced when photospheric motions braid field lines to the point of current sheet formation. In this contribution we address the ...
    • Dynamic properties of bright points in an active region 

      Keys, P.H.; Mathioudakis, M.; Jess, D.B.; MacKay, D.H.; Keenan, F.P. (2014-06-20) - Journal article
      Context. Bright points (BPs) are small-scale, magnetic features ubiquitous across the solar surface. Previously, we have observed and noted their properties for quiet Sun regions. Here, we determine the dynamic properties ...
    • The influence of the magnetic field on running penumbral waves in the solar chromosphere 

      Jess, David; Reznikova, V; Van Doorsselaere, Tom; Mackay, Duncan Hendry; Keys, Peter (2013-12-03) - Journal article
      We use images of high spatial and temporal resolution, obtained using both ground- and space-based instrumentation, to investigate the role magnetic field inclination angles play in the propagation characteristics of running ...
    • Magneto-static modeling from SUNRISE/IMaX : application to an active region observed with SUNRISE II 

      Wiegelmann, T.; Neukirch, Thomas; Nickeler, D. H.; Solanki, S. K.; Barthol, P.; Gandorfer, A.; Gizon, L.; Hirzberger, J.; Riethmüller, T. L.; Noort, M. van; Rodríguez, J. Blanco; Del Toro Iniesta, J. C.; Suárez, D. Orozco; Schmidt, W.; Pillet, V. Martínez; Knölker, M. (2017-03-22) - Journal article
      Magneto-static models may overcome some of the issues facing force-free magnetic field extrapolations. So far they have seen limited use and have faced problems when applied to quiet-Sun data. Here we present a first ...
    • Magneto-static modeling of the mixed plasma Beta solar atmosphere based on SUNRISE/IMaX data 

      Wiegelmann, Thomas; Neukirch, Thomas; Nickeler, Dieter; Solanki, Sami; Martinez Pillet, Valentin; Borrero, Juan Manule (2015-12) - Journal article
      Our aim is to model the 3D magnetic field structure of the upper solar atmosphere, including regions of non-negligible plasma beta. We use high-resolution photospheric magnetic field measurements from SUNRISE/IMaX as ...
    • Modeling the sun's small-scale global photospheric magnetic field 

      Meyer, Karen Alison; Mackay, Duncan Hendry (2016-10-19) - Journal article
      We present a new model for the Sun's global photospheric magnetic field during a deep minimum of activity, in which no active regions emerge. The emergence and subsequent evolution of small-scale magnetic features across ...
    • Photospheric observations of surface and body modes in solar magnetic pores 

      Keys, Peter H.; Morton, Richard J.; Jess, David B.; Verth, Gary; Grant, Samuel D.T.; Mathioudakis, Mihalis; Mackay, Duncan H.; Doyle, John G.; Christian, Damian J.; Keenan, Francis P.; Erdélyi, Robertus (2018-04-10) - Journal article
      Over the past number of years, great strides have been made in identifying the various low-order magnetohydrodynamic wave modes observable in a number of magnetic structures found within the solar atmosphere. However, one ...
    • The role of flux cancellation in eruptions from bipolar ARs 

      Yardley, S. L.; Green, L. M.; Driel-Gesztelyi, L. Van; Williams, D. R.; Mackay, D. H. (2018-10-10) - Journal article
      The physical processes or trigger mechanisms that lead to the eruption of coronal mass ejections (CMEs), the largest eruptive phenomenon in the heliosphere, are still undetermined. Low-altitude magnetic reconnection ...
    • Simulating the "Sliding Doors" Effect Through Magnetic Flux Emergence 

      MacTaggart, David; Hood, Alan William (2010-06-04) - Journal article
      Recent Hinode photospheric vector magnetogram observations have shown that the opposite polarities of a long arcade structure move apart and then come together. In addition to this "sliding doors" effect, orientations of ...
    • Simulating the coronal evolution of AR 11437 using SDO/HMI magnetograms 

      Yardley, Stephanie L.; Mackay, Duncan H.; Green, Lucie M. (2018-01-10) - Journal article
      The coronal magnetic field evolution of AR 11437 is simulated by applying the magnetofrictional relaxation technique of Mackay et al. (2011). A sequence of photospheric line-of-sight magnetograms produced by SDO/HMI are ...
    • The storage and dissipation of magnetic energy in the quiet sun corona determined from SDO/HMI magnetograms 

      Meyer, Karen Alison; Sabol, Juraj; Mackay, Duncan Hendry; van Ballegooijen, Aad (2013-05-30) - Journal article
      In recent years, higher cadence, higher resolution observations have revealed the quiet-Sun photosphere to be complex and rapidly evolving. Since magnetic fields anchored in the photosphere extend up into the solar corona, ...
    • Validation of the magnetic energy vs. helicity scaling in solar magnetic structures 

      Tziotziou, K.; Moraitis, K.; Georgoulis, M.K.; Archontis, V. (2014-10) - Journal item
      Aims. We assess the validity of the free magnetic energy - relative magnetic helicity diagram for solar magnetic structures. Methods. We used two different methods of calculating the free magnetic energy and the relative ...