@article{FeudelSeehaferRuediger1996,
  author    = {Feudel, Fred and Seehafer, Norbert and R{\"u}diger, Sten},
  title     = {Symmetry breaking bifurcations for the magnetohydrodynamic equations with helical forcing},
  series = {Preprint NLD},
  volume    = {31},
  journal   = {Preprint NLD},
  publisher = {Univ.},
  address   = {Potsdam},
  pages     = {10 S.},
  year      = {1996},
  language  = {en}
}
@article{Seehafer1995,
  author    = {Seehafer, Norbert},
  title     = {The turbulent electromotive force in the high-conductivity limit},
  year      = {1995},
  language  = {en}
}
@article{FeudelSeehaferSchmidtmann1995,
  author    = {Feudel, Fred and Seehafer, Norbert and Schmidtmann, Olaf},
  title     = {Fluid helicity and dynamo bifurcations},
  year      = {1995},
  language  = {en}
}
@article{SeehaferFeudelSchmidtmann1996,
  author    = {Seehafer, Norbert and Feudel, Fred and Schmidtmann, Olaf},
  title     = {Nonlinear dynamo with ABC forcing},
  year      = {1996},
  language  = {en}
}
@article{Seehafer1996,
  author    = {Seehafer, Norbert},
  title     = {Nature of the alpha effect in magnetohydrodynamics},
  year      = {1996},
  language  = {en}
}
@article{MirandaRempelChianetal.2013,
  author    = {Miranda, Rodrigo A. and Rempel, Erico L. and Chian, Abraham C.-L. and Seehafer, Norbert and Toledo, Benjamin A.},
  title     = {Lagrangian coherent structures at the onset of hyperchaos in the two-dimensional Navier-Stokes equations},
  year      = {2013},
  language  = {en}
}
@article{HassaninKliemSeehafer2016,
  author    = {Hassanin, Alshaimaa and Kliem, Bernhard and Seehafer, Norbert},
  title     = {Helical kink instability in the confined solar eruption on 2002 May 27},
  series = {Astronomische Nachrichten = Astronomical notes},
  volume    = {337},
  journal   = {Astronomische Nachrichten = Astronomical notes},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {0004-6337},
  doi       = {10.1002/asna.201612446},
  pages     = {1082 -- 1089},
  year      = {2016},
  language  = {en}
}
@article{KuzanyanPipinSeehafer2006,
  author    = {Kuzanyan, Kirill M. and Pipin, Valerij V. and Seehafer, Norbert},
  title     = {The alpha effect and the observed twist and current helicity of solar magnetic fields},
  issn      = {0038-0938},
  doi       = {10.1007/s11207-006-1636-6},
  year      = {2006},
  abstract  = {We present a straightforward comparison of model calculations for the alpha-effect, helicities, and magnetic field line twist in the solar convection zone with magnetic field observations at atmospheric levels. The model calculations are carried out in a mixing-length approximation for the turbulence with a profile of the solar internal rotation rate obtained from helioseismic inversions. The magnetic field data consist of photospheric vector magnetograms of 422 active regions for which spatially-averaged values of the force-free twist parameter and of the current helicity density are calculated, which are then used to determine latitudinal profiles of these quantities. The comparison of the model calculations with the observations suggests that the observed twist and helicity are generated in the bulk of the convection zone, rather than in a layer close to the bottom. This supports two-layer dynamo models where the large-scale toroidal field is generated by differential rotation in a thin layer at the bottom while the alpha-effect is operating in the bulk of the convection zone. Our previous observational finding was that the moduli of the twist factor and of the current helicity density increase rather steeply from zero at the equator towards higher latitudes and attain a certain saturation at about 12 - 15 degrees. In our dynamo model with algebraic nonlinearity, the increase continues, however, to higher latitudes and is more gradual. This could be due to the neglect of the coupling between small-scale and large-scale current and magnetic helicities and of the latitudinal drift of the activity belts in the model},
  language  = {en}
}
@article{DonnerSeehaferSanjuanetal.2006,
  author    = {Donner, Reik Volker and Seehafer, Norbert and Sanjuan, Miguel Angel Fernandez and Feudel, Fred},
  title     = {Low-dimensional dynamo modelling and symmetry-breaking bifurcations},
  series = {Physica. D, Nonlinear phenomena},
  volume    = {223},
  journal   = {Physica. D, Nonlinear phenomena},
  number    = {2},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0167-2789},
  doi       = {10.1016/j.physd.2006.08.022},
  pages     = {151 -- 162},
  year      = {2006},
  abstract  = {Motivated by the successful Karlsruhe dynamo experiment, a relatively low-dimensional dynamo model is proposed. It is based on a strong truncation of the magnetohydrodynamic (MHD) equations with an external forcing of the Roberts type and the requirement that the model system satisfies the symmetries of the full MHD system, so that the first symmetry-breaking bifurcations can be captured. The backbone of the Roberts dynamo is formed by the Roberts flow, a helical mean magnetic field and another part of the magnetic field coupled to these two by triadic mode interactions. A minimum truncation model (MTM) containing only these energetically dominating primary mode triads is fully equivalent to the widely used first-order smoothing approximation. However, it is shown that this approach works only in the limit of small wave numbers of the excited magnetic field or small magnetic Reynolds numbers (\$Rm ll 1\$). To obtain dynamo action under more general conditions, secondary mode},
  language  = {en}
}
@article{PalusKurthsSchwarzetal.2007,
  author    = {Palus, Milan and Kurths, J{\"u}rgen and Schwarz, Udo and Seehafer, Norbert and Novotna, Dagmar and Charvatova, Ivanka},
  title     = {The solar activity cycle is weakly synchronized with the solar inertial motion},
  doi       = {10.1016/j.physleta.2007.01.039},
  year      = {2007},
  abstract  = {We study possible interrelations between the 300-year record of the yearly sunspot numbers and the solar inertial motion (SIM) using the recently developed technique of synchronization analysis. Phase synchronization of the sunspot cycle and the SIM is found and statistically confirmed in three epochs (1734-1790, 1855-1875 and 1907-1960) of the whole period 1700-2000. These results give quantitative support to the hypothesis that there is a weak interaction between the solar activity and the SIM.},
  language  = {en}
}