(Back to the menu - click here.)

“Magnetic dynamos: the Earth, the Sun, and laboratory models

of the Earth´s magnetic field."

Date:

Download-files:

Time:

Thursday, 14 Jan 2021

Video-Recording for any system with MP4-support

- Video.mp4 (ca.292 Mb)

15:15 – 16:15

Abstract:

During the last solar maximum around 2014, we saw a host of x-class flares

and coronal mass ejections from the sun. We experienced few problems this time

on Earth due in part to the Earth's magnetic field, which shields us from much

of the Sun's charged particle radiation. Surprisingly, that field has weakened

throughout recorded history. The origin and dynamics of the magnetic fields

of the Earth, Sun, gas giants, and nearly every massive astrophysical object

raise numerous questions not completely resolved by existing theoretical,

computational and experimental work.

The next maximum of solar activity should be around 2024-2025.

In this talk I'll review the basics of the Earth's magnetic field, its reversals,

recent changes to the magnetic field, and an overview of the solar cycle.

Then we will discuss how laboratory experiments can help to understand

the processes. By using liquid sodium models of the Earth's core, different

international groups seek to better understand what determines the Earth's

magnetic field strength, pattern and dynamics by probing the effects of

turbulence, Lorentz forces and rotation on core dynamics.

While it is not possible to match every aspect of core dynamics in the lab,

the experiments seek a comparable force balance among rotation, magnetic

fields and advection.

Speaker today: Daniel Lathrop (University of Maryland)