How does Earth sustain its Mag Field?

  • Context: Undergrad 
  • Thread starter Thread starter morenogabr
  • Start date Start date
  • Tags Tags
    Earth Field
Click For Summary

Discussion Overview

The discussion focuses on Dynamo Theory and its role in sustaining Earth's magnetic field, exploring the mechanisms involved, particularly the effects of Earth's rotation and the properties of its molten core. The conversation includes theoretical explanations and seeks to clarify the underlying processes involved in magnetic field generation.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant requests a simplified explanation of Dynamo Theory suitable for a second-year astrophysics undergraduate.
  • Another participant notes that Earth's rotation and the presence of a molten, metallic, electrically conductive core are key factors in the theory.
  • A question is raised about how Earth's rotation induces electric currents in the conductive core.
  • It is proposed that the molten and conductive nature of the core allows for a significant number of free electrons to move, and that moving charges can generate magnetic fields.
  • One participant suggests that convection cells in the outer core are responsible for generating strong magnetic fields, but notes that adjacent cells may counter-rotate, potentially canceling each other's fields, leaving only a residual magnetic field that could collapse or reverse due to changes in convection patterns.

Areas of Agreement / Disagreement

Participants express various viewpoints regarding the mechanisms of Dynamo Theory and the specifics of how Earth's magnetic field is sustained, indicating that multiple competing views remain and the discussion is not resolved.

Contextual Notes

Some assumptions about the behavior of convection cells and their interactions are not fully explored, and the discussion does not resolve the complexities of the magnetic field generation process.

morenogabr
Messages
27
Reaction score
0
Anyone want to try explaining Dynamo Theory to a 2nd year astrophy undergrad? Short and simple will do...
 
Astronomy news on Phys.org
The Earth rotates and has a molten, metallic [electrically conductive] core.
 
so what is it about the Earths rotation that induces the current in this conductive core?
 
I do believe the core, since it is molten and conductive has a large number of free electrons moving around in it, and moving charges give rise to magnetic fields.
 
It's thought that convection cells in the fluid outer core generate strong magnetic fields, but the different adjacent cells are assumed to counter rotate, almost cancelling out each others field. Only a residual field remains that can collapse or reverse depending on changes in the core convection cells.

That's the abstract of this:

http://www.psc.edu/science/glatzmaier.html

Better post these things in the Earth Science forum.
 

Similar threads

High School How does the Sun's magnetic field affect Earth's geomagnetic field?
  • · Replies 23 ·
Replies
23
Views
5K
Undergrad Earth’s Magnetic field formula or downloadable vector field
  • · Replies 13 ·
Replies
13
Views
2K
Undergrad E- & Ions Deflection by Earth's Magnetic Field
  • · Replies 30 ·
2
Replies
30
Views
7K
High School Observing Orbital Mechanics from the 2nd Focus of Earth's Orbit
  • · Replies 8 ·
Replies
8
Views
2K
High School How the Earth's Magnetic field deflects the solar wind
  • · Replies 5 ·
Replies
5
Views
3K
Undergrad Could life on Earth survive the far future?
  • · Replies 16 ·
Replies
16
Views
3K
High School How long it takes the Earth to fall halfway to the Sun--ellipse method
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad Earth's gravitational field size.
  • · Replies 3 ·
Replies
3
Views
10K
High School The Earth's magnetic field and moon
  • · Replies 11 ·
Replies
11
Views
2K
Undergrad What's the effect of solar pole reversal on the Parker Spiral?
  • · Replies 3 ·
Replies
3
Views
2K