Publications (ADS, Google scholar) and Talks

 

Refereed Publications:

  1. 20. Warnecke, J.,: 2017, „Dynamo cycles in global convection simulations of solar-like stars“, Astron. Astrophys., submitted, [ArXiv], [PDF]


  1. 19. Viviani, M., Warnecke, J., Käpylä, M. J., Käpylä, P. J., Olspert, N., Cole-Kodikara, E. M., Lehtinen, J. J., and Brandenburg, A.: 2017, „Transition from nonaxi- to axisymmetric dynamo modes in spherical convection models of solar-like stars“, Astron. Astrophys., submitted, [ArXiv], [PDF]


  1. 18. Boro Saikia, S., Marvin,C. J.,  Jeffers, S. V., Reiners, A., Cameron, R. H., Marsden, S. C., Petit, P.,      Warnecke, J., and Yadav,  A. P.: 2017, „Göttingen chromospheric activity database -- Questioning the active branch of stellar cycles, Astron. Astrophys., submitted


  1. 17. Warnecke, J., Rheinhardt, M., Tuomisto, S., Käpylä, P. J., Käpylä, M. J., and Brandenburg, A.: 2017, „Turbulent transport coefficients in spherical wedge dynamo simulations of solar-like stars“, Astron. Astrophys., in press, [ArXiv], [DOI],[PDF]


  1. 16. Warnecke, J., Chen, F., Bingert, S., and Peter, H.: 2017, „Current systems in coronal loops in 3D MHD simulations“, Astron. Astrophys., 607, A53, [ArXiv],[DOI],[ADS],[PDF]


  1. 15. Gent, F., Käpylä, M. J., and Warnecke, J.: 2017, „Long-term variations of turbulent transport coefficients in a solar-like convective dynamo simulation“, Astron. Nachr.,388, 885, [ArXiv],[DOI],[ADS],[PDF]


  1. 14. Käpylä, P. J., Rheinhardt, M., Brandenburg, A., Arlt R., Käpylä, M. J., Lagg A., Olspert, N., and  Warnecke, J.: 2017, „Extended subadiabatic layer in simulations of overshooting convection“, Astrophys. J. Lett., 845, L23, [ArXiv],[DOI],[ADS],[PDF]


  1. 13. Käpylä, P. J., Käpylä, M. J., Warnecke, J., Olspert, N., and Brandenburg, A.: 2017 „Convection-driven spherical shell dynamos at varying Prandtl numbers“, Astron. Astrophys., 599, A18, [ArXiv],[DOI],[ADS],[PDF]


  1. 12. Warnecke, J., Käpylä, P. J., Käpylä, M. J., & Brandenburg, A.: 2016, „Influence of a coronal envelope as a free boundary to global convective dynamo simulations“, Astron. Astrophys., 596, A115, [ArXiv], [ADS], [DOI],[PDF].


  1. 11. Warnecke, J., Losada, I. R., Brandenburg, A., Kleeorin, N., & Rogachevskii, I.: 2016, „Bipolar region formation in stratified two-layer turbulence,'' Astron. Astrophys., 589, A125, [ArXiv],[ADS],[DOI],[PDF].


  1. 10. Käpylä, M. J., Käpylä, P. J., Olspert, N., Brandenburg, A., Warnecke, J., Karak, B. B. and Pelt, J.: 2016, „Multiple dynamo modes as a mechanism for long-term solar activity variation“, Astron. Astrophys., 589, A56, [ArXiv],[ADS},[DOI],[PDF].


  1. 9.Peter, H., Warnecke, J., Chitta, L.P., Cameron, R.H.: 2015, „Limitations of force-free magnetic field extrapolations: revisiting basic assumptions“, Astron. Astrophys., 584, A68, [ArXiv],[ADS],[DOI],[PDF].


  1. 8.Warnecke, J., Käpylä, P. J., Käpylä, M. J., & Brandenburg, A.: 2014, „On the cause of solar-like equatorward migration in global convective dynamo simulations“, Astrophys. J. Lett., 796, L12, [ArXiv],[ADS],[DOI],[PDF]


  1. 7.Warnecke, J., Käpylä, P. J., Mantere, M. J., & Brandenburg, A.: 2013, „Spoke-like differential rotation in a convective dynamo with a coronal envelope”, Astrophys. J., 777, 148, [ArXiv],[ADS],[DOI],[PDF]


  1. 6.Käpylä, P. J., Mantere, M. J., Cole, E., Warnecke, J., & Brandenburg, A.: 2013, “Effects of strong stratification on equatorward dynamo wave propagation”, Astrophys. J., 778, 48 ,[ArXiv],[ADS],[DOI],[PDF]


  1. 5.Warnecke, J., Losada, I. R., Brandenburg, A., Kleeorin, N., & Rogachevskii, I.: 2013, “Bipolar      magnetic structures driven by stratified turbulence with a coronal envelope,'' Astrophys. J. Lett., 777, L37 [ArXiv],[ADS],[DOI],[PDF].


  1. 4.Warnecke, J., Käpylä, P. J., Mantere, M. J., & Brandenburg, A.: 2012, “Ejections of magnetic structures above a spherical wedge driven by a convective dynamo with differential rotation”, Solar Phys. 280, 299-319 [ArXiv],[ADS],[DOI][PDF]


  1. 3.Warnecke, J., Brandenburg, A., & Mitra, D.: 2012, “Magnetic twist: a source and property of space weather'', J. Spa. Weather Spa. Clim. 2, A11 [ArXiv],[ADS],[DOI],[PDF]


  1. 2.Warnecke, J., Brandenburg, A., & Mitra, D.: 2011, “Dynamo-driven plasmoid ejections above a spherical surface”, Astron. Astrophys. 534, A11. [ArXiv],[ADS],[DOI],[PDF]


  1. 1.Warnecke, J., & Brandenburg, A.: 2010, “Surface appearance of dynamo-generated large-scale fields”, Astron. Astrophys. 523, A19. [ArXiv],[ADS],[DOI],[PDF]



ProceedingS:


  1. 7.Losada, I. R., Warnecke, J., Glogowski, K. Roth, M, Brandenburg, A., Kleeorin, N. & Rogachecskii, I.: 2017, “A new look at sunspot formation using theory and observation“, in Fine Structure and Dynamics of the Solar Atmosphere, ed.  A.G. Kosovichez et al., Proc. IAU Symp., Vol. 327, in press, [ArXiv],[PDF]


  1. 6.Warnecke, J., & Brandenburg, A.: 2013, “Coronal influence on dynamos”, in Magnetic Fields–Throughout  Stellar Evolution, ed. M. Jardine, P. Petit, & H. Spruit, Proc. IAU Symp., Vol. 302, pp.134-137,[ArXiv],[ADS],[DOI],[PDF]


  1. 5.Warnecke, J., Käpylä, P. J., Mantere, M. J., & Brandenburg, A.: 2012, “Solar-like differential rotation and equatorward migration in a convective dynamo with a coronal envelope,'' in Solar and astrophysical dynamos and magnetic activity, ed. A. Kosovichev, Proc. IAU Symp., Vol. 294, pp. 307-312, [ArXiv],[ADS],[DOI],[PDF]


  1. 4.Warnecke, J., Käpylä, P. J., Mantere, M. J., & Brandenburg, A.: 2011, “Coronal ejections from convective spherical shell dynamos”, in Comparative Magnetic Minima: Characterizing quiet times in the Sun and stars, ed. C. H. Mandrini & D. F. Webb, Proc. IAU Symp., Vol. 286, pp. 154-158 [ArXiv],[ADS],[DOI],[PDF]


  1. 3.Warnecke, J., Brandenburg, A., & Mitra, D.: 2011, “Plasmoid ejections driven by dynamo action underneath a spherical surface”, in Advances in Plasma Astrophysics, ed. Proc. IAU, Vol. 6, IAU Symp. S274, A. Bonanno, E. de Gouveia dal Pino, & A. Kosovichev, pp. 306-309 [ArXiv],[ADS], [DOI],[PDF]


  1. 2.Warnecke, J., & Brandenburg, A.: 2011, “Dynamo generated field emergence through recurrent plasmoid ejections”, in Physics of Sun and Star Spots, ed. IAU Symp. 273, D.P. Choudhary & K.G. Strassmeier, pp. 256-260 [ArXiv],[ADS],[PDF]


  1. 1.Warnecke, J., & Brandenburg, A.: 2011, “Recurrent flux emergence from dynamo-generated fields”, in Astrophysical Dynamics: from Stars to Galaxies, ed. IAU Symp. 271, N. Brummell, & A.S. Brun, pp. 407-408 [ArXiv],[ADS],[PDF])



Invited TalKs:


September 2017: Dynamo mechanism for magnetic activity and cycles of stars, Splinter Session: Solar and stellar activity and variability'' at Annual Meeting of the Astronomische Gesellschaft, Göttingen, Germany.


December 2016: Dynamo Breakout session: the role of magnetic helicity and its fluxes, Max Planck Princeton Center Meeting, Princeton, US.


December 2016: The Test--field method and its applications, Max Planck Princeton Center Meeting, Princeton, US.


April 2016: Connecting the solar dynamo below the surface with ejection of twisted magnetic fields above the surface, Space Climate 6, Levi, Finland.


October 2015: Stellar Dynamos, Invited lecture, Dynamos in a Nutshell, Max-Planck-Institut für Sonnensystemforschung, Göttingen, Germany.


October 2015: Understanding Solar and Stellar Activity with Numerical Simulations, CS Forum talk, School of Science, Aalto University, Finland.


June 2015: Connecting the solar dynamo below the surface with ejection of twisted magnetic fields above the surface, Forecasts and Warnings of Extreme Storms at the Sun, Lund, Sweden.


February 2015: Understanding the solar dynamo from numerical simulations, Mathematics Seminar, Division of Mathematics, University of Dundee, UK Sweden.


August 2014: Dynamo driven coronal ejections, ICS Forum talk, School of Science, Aalto University, Finland.


October 2013: Bipolar magnetic structures driven by stratified turbulence with a coronal envelope, Astrophysics Seminar, Department of Physics, Helsinki University, Finland.


June 2013: Combining Models of Coronal Mass Ejections and Solar Dynamos, Seminar, Max-Planck-Institute for Solar System Research, Germany.


November 2012: Equatorward migration and spoke-like differential rotation due to a spherical dynamo with a coronal envelope, Astrophysics Seminar, Department of Physics, Helsinki University, Finland.


June 2011: Flux emergence: Coronal ejections driven by dynamo action underneath the solar surface, Astrophysics Seminar, Department of Physics, Helsinki University, Finland.


April 2010: Surface appearance of dynamo-generated large-scale fields, Colloquium talk, Kiepenheuer-Institute for Solar Physics, Freiburg, Germany.


Public TalKs:


November 2011: Nearby Astronomy: Our own Star, Talk at the Telescope Show, Astronomy Department, Stockholm University, Sweden.


May 2016: Unser Stern: Die Sonne, Talk during the public event of the Mercury Transit, MPS, Göttingen, Germany.


June 2016: Die Sonne und ihr Magnetfeld, Talk for 8th Grade School class, MPS, Göttingen, Germany.


Thesis:


PhD Thesis:

Combining Models of Coronal Mass Ejections and Solar Dynamos, Thesis


Licentiate:

Flux emergence: Flares and coronal mass ejections driven by dynamo action underneath the solar surface, Thesis


Diplom arbeit / Master thesis:

Einfluss photospärischer Bewegung auf die Struktur der solaren Korona, Thesis