The objective of this project was to investigate whether magnetic reconnection in the space environment has a characteristic scale in space and time by characterising statistically the spatial and temporal structure of the footprint of reconnection as observed in the Earth’s ionosphere. This knowledge has the potential to provide constraints for multi-scale reconnection models. In this project the reconnection character was inferred from auroral boundary motion in conjunction with a reconnection model.
The most important achievements of the project were:
Longden, N., Chisham, G., Freeman, M.P., Abel, G.A., and Sotirelis, T. (2010), Estimating the location of the open-closed magnetic field line boundary from auroral images, Ann. Geophys., 28, 1659-1678, doi:10.5194/angeo-28-1659-2010.
Longden, N., Chisham, G., and Freeman, M.P. (2014), Magnetic local time variation and scaling of poleward auroral boundary dynamics, J. Geophys Res., 119, 10006-10022, doi:10.1002/2014JA020430.
Auroral oval boundary locations derived from IMAGE FUV images are available to download covering the period from May 2000 until October 2002.
These files contain version 1.1 of our auroral boundaries, released in June 2010 (version 1.0, released in April 2010 can be found here). The technique used to obtain these boundaries is outlined here. More details and examples are given in Longden et al., (2010), currently under review. Please read the following notes about the data prior to use.
For more information regarding these auroral boundaries or their use, please contact Gareth Chisham.
When using these auroral boundary data, please acknowledge their source. In particular, when using them in a publication please cite the paper describing the technique used to obtain the boundaries. This paper is currently under review and a link to the publication will be added when available. Please also include the following acknowledgment, ‘Auroral boundary data were derived and provided by the British Antarctic Survey based on IMAGE satellite data (https://www.bas.ac.uk/project/image-auroral-boundary-data/).’
The data in each file are presented as a comma separated list with the following values:
|1||Timestamp in UT in YYYY-MM-DD HH:MM:SS format|
|2||IMAGE FUV Instrument Code|
|3 to 26||Magnetic latitude of equatorward boundary locations in AACGM coordinates|
|27 to 50||Magnetic latitude of poleward boundary locations in AACGM coordinates|
The auroral boundary locations are given for 1 hour magnetic local time (MLT) bins in ascending order from 00:30 to 23:30 MLT (ie, starting with the 0 to 1 MLT bin and ending with the 23 to 24 MLT bin).
NaN values indicate missing values or MLT sectors for which the auroral boundary locations could not be made successfully.
The auroral boundary locations are “uncorrected”, ie, step 8 of the boundary location technique has not been performed. It is recommended that our suggested correction values be added to the poleward auroral boundaries provided in the data if these boundaries are to be used as a proxy for the open-closed magnetic field line boundary.
The IMAGE FUV instrument codes are as follows: