### What's in a geomagnetic measurement?

#### (supervisor: Heather McCreadie)

Nature of project: **theory**, data analysis

Available to
students on full-time physics degree schemes or joint students.

#### Project description and methodology

The Earth's magnetic field is measured on the ground in many places on the Earth. Each measurement is composed of several sources. This project aims to outline each source and show its signature in some magnetograms. The student will have to learn how to download and plot magnetograms and perform data analysis.

This project can be geared for a student who is interested in physics and programming. Some of the progamming can be oriented to obtaining information from digital images.

An overall understanding of the Earth's magnetic field will be gained from this project.The field fluctuations have sources inside the Earth and from the solar wind.

*A successful project will develop beyond the above in one/some of the following directions:*

If the student can derive an algorithm to read digitised magnetograms this would develop the area.

When considering where to take your project, please bear in mind the time available. It is preferable to do fewer things well than to try many and not get conclusive results on any of them. However, sometimes it is useful to have a couple of strands of investigation in parallel to work on in case delays occur.

*Additional scope or challenge if taken as a Year-4 project:* choice

1. Algorithms which pick out certain geomagnetic events from magnetograms rather than showing already known events can be written by 4th year students.

2. Writing an algorithm to determine the secular variation and comparing this with other algorithms can also be written by a fourth year student.

Please speak to **Heather McCreadie** (hem18) if you consider doing this project.

*Initial literature for students:*

- Chapman and Bartels - Geomagnetism Vols 1-2. (1940).
- Archive of data - http://wdc.kugi.kyoto-u.ac.jp/caplot/index.html
- https://www.journals.elsevier.com/signal-processing
- https://sisu.ut.ee/imageprocessing/book/1

#### Novelty, degree of difficulty and amount of assistance required

Initial help with matlab programming will be given.

#### Project milestones and deliverables (including timescale)

milestone | to be completed by |

understanding of data given shown | end of October |

programming begun | Christmas |

events chosen | end of February |

discussion | Easter |