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Disputation: Helle Merethe Bakke

Doctoral candidate Helle Merethe Bakke at the Institute of Theoretical Astrophysics, Faculty of Mathematics and Natural Sciences, is defending the thesis "Impact of nanoflare heating in the lower solar atmosphere" for the degree of Philosophiae Doctor.

portrait photo of a young, smiling woman
Doctoral candidate Helle Merethe Bakke. Photo: UiO.

Join the disputation

The PhD defence and trial lecture will be 100% in-person. Please make sure to be early because the doors will close on time.

Join the trial lecture - 27th of October at 10:15 (Aud. 209, Svein Rosselands Hus)

"How will the James Webb Space Telescope transform our understanding of exoplanets?"

Conferral summary

Hva er grunnen til at solas korona er flere millioner grader når den synlige overflaten bare er noen tusen grader? En av de ledende kandidatene som kan forklare den høye temperature er nanobluss, som er små, energirike begivenheter assosiert med solas magnetfelt. Denne avhandlingen anvender numeriske simuleringer til å utforske nanobluss sin rolle i oppvarmingen av solas atmosfære, og undersøker det diagnostiske potensialet for tilstedeværelsen av nanobluss i solas atmosfære gjennom analyse av syntetiske spektrallinjer. 

The role of nanoflares in the solar atmosphere:

Understanding the mechanisms responsible for heating the solar atmosphere from a few thousand Kelvin in the photosphere to millions of degrees in the corona is a major challenge in solar physics. A number of potential heating mechanisms are continuously studied, and one of the leading candidates is called the nanoflare theory. Nanoflares are small-scale heating events associated with magnetic reconnection, and the heating mechanism is based on the theory that nanoflares occur frequently throughout the solar atmosphere and heat the corona consistently. However, proving this theory has been difficult because the energy released from nanoflares is below the detection threshold of current instrumentation and nanoflares have therefore not been observed yet.

So how can we study a phenomenon that is not observable? In this work we utilize numerical simulations in order to investigate the presence and properties of nanoflares in the solar atmosphere. By analysing the atmospheric response to nanoflare heating, it is possible to probe potential heating signatures in simulations to get an idea of what to look for in observations. In our exploration of the nanoflare theory, we have investigated the diagnostic potential of nanoflares by analysing heating signatures in the lower atmosphere and compared our numerical results to an observation of a small-scale coronal heating event.

image contains grey, blue smokes simulating accelerated electrons
Si IV 140.3 nm line core intensity in a Bifrost simulation with accelerated electrons. Credits: H. Bakke.

 

Contact information for the Department

Tags: PhD defense, disputas, solar physics, Simulations
Published Oct. 13, 2023 10:00 AM - Last modified Oct. 17, 2023 1:05 PM