Disputas: Juan Martínez-Sykora

Licenciado en Física Juan Martínez-Sykora ved Institutt for teoretisk astrofysikk vil forsvare sin avhandling for graden ph.d. (philosophiae doctor): Flux emergence from the convection zone to the corona

Prøveforelesning

Se prøveforelesning

Bedømmelseskomité

Dr. Yuhong Fan, National Center for Atmospheric Research, Boulder, CO, USA.
Dr. Vasilis Archontis, University of St. Andrews, St. Andrews, Fife, UK
Professor Egil Leer, Universitetet i Oslo

Leder av disputas:  Per B. Lilje

Veileder:  Viggo Hansteen og Mats Carlsson

Sammendrag

Solens ytre atmosfære er gjennomsyret av magnetfelt. Et sentralt spørsmål er hvordan disse feltene er forbundet med områder under solens synlige overflate og, videre, hvordan magnetfeltet stiger fra områder det er generert som resultat av dynamoprosesser opp til overflaten. I denne avhandlingen beregner vi, for første gang, realistiske numeriske modeller der en følger magnetiske fluksrør fra det øvre konveksjonslaget helt opp til solens korona.

Solar magnetism lies at the root of most solar and heliospheric physics. The intricate structure of the solar field, the activity cycle and the influence of the field on the heliosphere represent major quests of (astro-) physics which bear directly on the human environment. The sun's magnetic field is generated by enigmatic dynamo processes in the solar interior, is organized into the highly complex patterns of solar activity observed in the solar photosphere, dominates the structure of the outer solar atmosphere (chromosphere, transition region and corona), regulates the solar wind, and affects the whole extended heliosphere into the Earth's upper atmosphere. Solar activity modulation affects satellite orbits and influences jet stream patterns.

In this thesis we, for the first time, compute realistic numerical models where we follow the rise of buoyant magnetic tubes from the upper convection zone all the way up into the million-degree corona. A number of interesting phenomena have been discovered and are reported in the thesis. These discoveries are not only related to magnetic tube evolution, but also to the perturbation, dynamics, and variation of the solar atmosphere. The research carried out for this thesis has been done at the Institute of Theoretical Astrophysics at the University of Oslo.

Kontaktperson

For mer informasjon, kontakt Egil Leer.

Publisert 30. mars 2012 15:47 - Sist endret 13. apr. 2012 10:17