# Prosiectau Ffiseg ar gyfer myfyrwyr bl.3 a bl.4

### Statistical analysis of yearly variation in the equatorial electrojet

#### (supervisor: Heather McCreadie)

Nature of project: data analysis, theory

Available to students on full-time physics degree schemes only.

#### Project description and methodology

The equatorial electrojet is a current jet which flows in the day time along the Earth's geomagnetic equator at 108 km altitude. A new data set has become available, SWARM. The data are a similar format to CHAMP data, however with three satellites in a special configuration, enabling an extra dimension to be added to the analysis. The project requires the student to become familiar with download procedures from ESA. Then using programs already written initial plots to check the data from individual satellites will be analysed. The student will then splice the data and analyse the set in the new dimension. Hodo diagrams of the annual variations of the electrojet will hopefully yield information towards the structure of the electrojet.

A successful project will develop beyond the above in one/some of the following directions:
Continue development of a computer package for reading the archive data to a point where it is useable by anyone.

Develop ideas for analysing the data in a dimension not used before. This requires extensive use of MatLab.

Determine the underlying physics of the structure of the equatorial electrojet.

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: Additional depth and understanding of data analysis technique.

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

Initial literature for students:

1. McCreadie, H.(2005) Classes of equatorial electrojet. In Earth observations of CHAMP, eds C.Reigberg et al. 401-406
2. Archana, R. K., Phani Chandrasekhar, N., Arora, K., & Nagarajan, N. (2018). Constraints on scale lengths of equatorial electrojet and counter electrojet phenomena from the Indian sector. Journal of Geophysical Research: Space Physics, 123. https://doi.org/10.1029/2018JA025213
3. Alken, P., & Maus, S. (2007). Spatio-temporal characterization of the equatorial electrojet from CHAMP, Orsted and SAC-C satellite measurements. Journal of Geophysical Research, 112, A09305. https://doi.org/10.1029/2007JA012524
4. Chandrasekhar, N. P., Arora, K., & Nagarajan, N. (2014b). Characterization of seasonal and longitudinal variability of EEJ in the Indian region. Journal of Geophysical Research: Space Physics , 119, 10,242 –10,259. https://doi.org/10.1002/2014JA020183

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

This project will allow the student to create a set of routines to read a specific data base. Using these routines some analysis will be performed. Use of MatLab is required so H. McCreadie's packages can be used.

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

milestoneto be completed by
Data gather and determination of new code required end of October
instrument and data base familiarisationChristmas
Hodo diagram code finalised end of February
analysisEaster