Publications (ADS, GS) and Talks

 

Refereed Publications:

  1. 33. Stejko, A. M., Kosovichev, A. G., Featherstone, N. A., Guerrero, G., Hindman, B. W., Matilsky, L. I., Warnecke, J.: 2022, „Constraining Global Solar Models through Helioseismic Analysis“, Astrophys. J., submitted, [ArXiv],[PDF]


  1. 32. Warnecke, J., and Peter, H.: 2022, „On the influence of magnetic helicity on X-rays emission of solar and stellar coronae“, Astron. Astrophys., submitted, [ArXiv],[PDF]


  1. 31. Dikpati, M., Gilman, P. A., Guerrero, G. A., Kosovichev, A. G., McIntosh, S. W., Sreenivasan, K. R., Warnecke, J. and Zaqarashvili, T. V.: 2022, Simulating solar near-surface rossby waves by inverse-cascade from supergranule energy, Astrophys. J., 931, 117, [DOI],[ADS],[PDF]


  1. 30. Warnecke, J., Rheinhardt, M., Viviani, M., Gent, F., Tuomisto, S. and Käpylä, M. J.: 2021, „Investigating global convective dynamos with mean-field models: full spectrum of turbulent effects required“, Astrophys. J. Lett., 919 L13, [ArXiv],[DOI],[ADS],[PDF]


  1. 29. Zhuleku, J., Warnecke, J. and Peter, H.: 2021, „Stellar X-rays and magnetic activity in 3D MHD coronal model“, Astron. Astrophys., 652, A32, [ArXiv],[DOI],[ADS],[PDF]


  1. 28. Pencil Code Collaboration, Brandenburg, A., Johansen, A., Bourdin, P. A., Dobler, W., Lyra, W., Rheinhardt, M., Bingert, S., Haugen, N. E. L., Mee, A., Gent, F., Babkovskaia, N., Yang, C. -C., Heinemann, T., Dintrans, B., Mitra, D., Candelaresi, S., Warnecke, J., Käpylä, P. J., Schreiber, A., Chatterjee, P., Käpylä, M. J., Li,  X. -Y., Krüger, J., Aarnes, J. R., Sarson, G. R., Oishi, J. S., Schober, J., Plasson, R., Sandin, C., Karchniwy, E., Rodrigues, L. F. S., Hubbard, A., Guerrero, G., Snodin, A., Losada, I. R., Pekkilä, J. and Qian, C., T.: 2020, „The Pencil Code, a modular MPI code for partial differential equations and particles: multipurpose and multiuser-maintained“, Journal for Open Source Software (JOSS), 6, 2807, [ArXiv],[DOI],[ADS],[PDF]


  1. 27. Warnecke, J. and Käpylä, M. J.: 2020, „Rotational dependence of turbulent transport coefficients in global convective dynamo simulations of solar-like stars“, Astron. Astrophys., 642, A66, [ArXiv],[DOI],[ADS],[PDF]


  1. 26. Zhuleku, J., Warnecke, J. and Peter, H.: 2020, „Stellar coronal X-ray emission and surface magnetic flux“, Astron. Astrophys., 640, A119, [ArXiv],[DOI],[ADS],[PDF]


  1. 25. Willamo, T., Hackman, T., Lehtinen, J. J., Käpylä, M. J., Olspert, N., Viviani, M., and Warnecke, J.: 2020, „Shapes of stellar activity cycles“, Astron. Astrophys., 638, A69, [ArXiv],[DOI],[ADS],[PDF]


  1. 24. Warnecke, J., and Bingert, S.: 2020, „Non-Fourier description of heat flux evolution in 3D MHD simulations of the solar corona“, Geophys. Astrophys. Fluid Dyn. 114, 261,[ArXiv],[DOI],[ADS],[PDF]


  1. 23. Viviani, M., Käpylä, M. J., Warnecke, J., Käpylä, P. J. and Rheinhardt, M.: 2019, „Stellar dynamos in the transition regime: multiple dynamo modes and anti-solar differential rotation“, Astrophys. J. Lett.,886, 1, [ArXiv],[DOI],[ADS],[PDF]


  1. 22. Warnecke, J., and Peter, H.: 2019, „Data-driven model of the solar corona above an active region“, Astron. Astrophys., 624, L12, [ArXiv],[DOI],[ADS],[PDF]


  1. 21. Losada, I. R., Warnecke, J., Brandenburg, A., Kleeorin, N., & Rogachevskii, I.: 2019, „Magnetic bipoles in rotating turbulence with coronal envelope,'': Astron. Astrophys., 621, A61, [ArXiv],[DOI],[ADS],[PDF]


  1. 20. Viviani, M., Warnecke, J., Käpylä, M. J., Käpylä, P. J., Olspert, N., Cole-Kodikara, E. M., Lehtinen, J. J., and Brandenburg, A.: 2018, „Transition from nonaxi- to axisymmetric dynamo modes in spherical convection models of solar-like stars“, Astron. Astrophys., 616, A160, [ArXiv],[DOI],[ADS],[PDF]


  1. 19. 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.: 2018, „Chromospheric activity catalogue of 4454 cool stars -- Questioning the active branch of stellar cycles, Astron. Astrophys., 616, A108, [ArXiv],[DOI],[ADS],[PDF]


  1. 18. Warnecke, J.,: 2018, „Dynamo cycles in global convection simulations of solar-like stars“, Astron. Astrophys., 616, A72, [ArXiv],[DOI],[ADS],[PDF]


  1. 17. Warnecke, J., Rheinhardt, M., Tuomisto, S., Käpylä, P. J., Käpylä, M. J., and Brandenburg, A.: 2018, „Turbulent transport coefficients in spherical wedge dynamo simulations of solar-like stars“, Astron. Astrophys., 609, A51, [ArXiv],[DOI],[ADS],[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 2021: Investigating global convective dynamos with mean-field models: full spectrum of turbulent effects required, Virtual Nordic Dynamo Seminar, Nordita Stockholm.


June 2021: Modelling solar and stellar activity driven by turbulent dynamo effects and helicity, Online Advanced Study Program on Helicities in Astrophysics and Beyond.


April 2021: Modelling solar and stellar activity driven by turbulent dynamo effects, Symposium: Recent Developments in Magnetohydrodynamics and Dynamo Theory at British Applied Mathematics Colloquium, Glasgow, UK (canceled because of sudden illness).


March 2021: Modelling solar and stellar activity from the dynamo to the corona, Astrophysical Colloquium, University of Graz, Austria.


February 2021: Modelling solar and stellar activity driven by turbulent dynamo effects, Virtual Nordic Dynamo Seminar, Nordita Stockholm.


January 2021: Small-scale Dynamo Action at Very Low Magnetic Prandtl Numbers, Dynamo Breakout session: Max Planck Princeton Center Meeting, Virtual.


February 2020: Data-driven models of the solar corona, Solar physics Colloquium, Institute for Astronomy, University of Hawaii, USA.


February 2020: Modelling solar and stellar activity, Colloquium, Institute for Astronomy, University of Hawaii, USA.


July 2019: Modelling solar and stellar activity driven by turbulent dynamo effects, Space Climate 7, Canton Orford, Québec, Canada.


March 2019: Magnetic Helicity: The glue that connects dynamos and coronae of the Sun and stars, Solar Helicities in Theory and Observations: Implications for Space Weather and Dynamo Theory, Nordita Program, Stockholm, Sweden.


June 2018: Open questions and the future of dynamo simulations, From space, solar and laboratory plasmas to plasma astrophysics, MPS, Göttingen, Germany.


June 2018: Modeling solar and stellar activity – from the dynamo to the corona, Institute Colloquium, Leibniz-Institut für Astrophysik Potsdam (AIP), Göttingen, Germany.


February 2018: What can numerical simulations tell us about the mechanism of solar and stellar activity?, European Solar Physics Online Seminars, hosted by Max Planck Institute for Solar System Research, Göttingen, Germany.


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:


May 2021: A sky disk changed the history of astronomy, public science talk at the Pencil Code User meeting, Lausanne, EPFL, Switzerland.


November 2018: Die Sonne, unser magnetischer Stern, invited lecture for Highschool-teacher education seminar (bundesweiten Lehrerfortbildung zur Astronomie), Haus der Astronomie, Heidelberg.


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


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


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



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