A new angle for probing field-aligned irregularities with the Murchison Widefield Array
Electron density irregularities in the ionosphere are known to be magnetically anisotropic, preferentially elongated along the lines of force. While many studies of their morphology have been undertaken by topside sounding and whistler measurements, it is only recently that detailed regional-scale r...
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Journal Article |
| Published: |
Blackwell Publishing Ltd
2016
|
| Online Access: | http://purl.org/au-research/grants/arc/DE140100316 http://hdl.handle.net/20.500.11937/35169 |
| _version_ | 1848754422846324736 |
|---|---|
| author | Loi, S. Murphy, T. Cairns, I. Trott, Cathryn Hurley-Walker, Natasha Feng, L. Hancock, Paul Kaplan, D. |
| author_facet | Loi, S. Murphy, T. Cairns, I. Trott, Cathryn Hurley-Walker, Natasha Feng, L. Hancock, Paul Kaplan, D. |
| author_sort | Loi, S. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Electron density irregularities in the ionosphere are known to be magnetically anisotropic, preferentially elongated along the lines of force. While many studies of their morphology have been undertaken by topside sounding and whistler measurements, it is only recently that detailed regional-scale reconstructions have become possible, enabled by the advent of widefield radio telescopes. Here we present a new approach for visualizing and studying field-aligned irregularities (FAIs), which involves transforming interferometric measurements of total electron content gradients onto a magnetic shell tangent plane. This removes the perspective distortion associated with the oblique viewing angle of the irregularities from the ground, facilitating the decomposition of dynamics along and across magnetic field lines. We apply this transformation to the data set of Loi et al. (2015a), obtained on 15 October 2013 by the Murchison Widefield Array (MWA) radio telescope and displaying prominent FAIs. We study these FAIs in the new reference frame, quantifying field-aligned and field-transverse behavior, examining time and altitude dependencies, and extending the analysis to FAIs on subarray scales. We show that the inclination of the plane can be derived solely from the data and verify that the best fit value is consistent with the known magnetic inclination. The ability of the model to concentrate the fluctuations along a single spatial direction may find practical application to future calibration strategies for widefield interferometry, by providing a compact representation of FAI-induced distortions. |
| first_indexed | 2025-11-14T08:40:10Z |
| format | Journal Article |
| id | curtin-20.500.11937-35169 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T08:40:10Z |
| publishDate | 2016 |
| publisher | Blackwell Publishing Ltd |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-351692022-09-01T02:31:50Z A new angle for probing field-aligned irregularities with the Murchison Widefield Array Loi, S. Murphy, T. Cairns, I. Trott, Cathryn Hurley-Walker, Natasha Feng, L. Hancock, Paul Kaplan, D. Electron density irregularities in the ionosphere are known to be magnetically anisotropic, preferentially elongated along the lines of force. While many studies of their morphology have been undertaken by topside sounding and whistler measurements, it is only recently that detailed regional-scale reconstructions have become possible, enabled by the advent of widefield radio telescopes. Here we present a new approach for visualizing and studying field-aligned irregularities (FAIs), which involves transforming interferometric measurements of total electron content gradients onto a magnetic shell tangent plane. This removes the perspective distortion associated with the oblique viewing angle of the irregularities from the ground, facilitating the decomposition of dynamics along and across magnetic field lines. We apply this transformation to the data set of Loi et al. (2015a), obtained on 15 October 2013 by the Murchison Widefield Array (MWA) radio telescope and displaying prominent FAIs. We study these FAIs in the new reference frame, quantifying field-aligned and field-transverse behavior, examining time and altitude dependencies, and extending the analysis to FAIs on subarray scales. We show that the inclination of the plane can be derived solely from the data and verify that the best fit value is consistent with the known magnetic inclination. The ability of the model to concentrate the fluctuations along a single spatial direction may find practical application to future calibration strategies for widefield interferometry, by providing a compact representation of FAI-induced distortions. 2016 Journal Article http://hdl.handle.net/20.500.11937/35169 10.1002/2015RS005878 http://purl.org/au-research/grants/arc/DE140100316 Blackwell Publishing Ltd fulltext |
| spellingShingle | Loi, S. Murphy, T. Cairns, I. Trott, Cathryn Hurley-Walker, Natasha Feng, L. Hancock, Paul Kaplan, D. A new angle for probing field-aligned irregularities with the Murchison Widefield Array |
| title | A new angle for probing field-aligned irregularities with the Murchison Widefield Array |
| title_full | A new angle for probing field-aligned irregularities with the Murchison Widefield Array |
| title_fullStr | A new angle for probing field-aligned irregularities with the Murchison Widefield Array |
| title_full_unstemmed | A new angle for probing field-aligned irregularities with the Murchison Widefield Array |
| title_short | A new angle for probing field-aligned irregularities with the Murchison Widefield Array |
| title_sort | new angle for probing field-aligned irregularities with the murchison widefield array |
| url | http://purl.org/au-research/grants/arc/DE140100316 http://hdl.handle.net/20.500.11937/35169 |