Seasonal influence on polar cap patches in the high-latitude nightside ionosphere
The influence of the season on the patch-to-background density ratio of polar cap patches in the nightside ionosphere was observed above northern Scandinavia around solar maximum (1999–2001). This is the first study of the seasonal effect in the nightside polar ionosphere. The observations were cond...
Published in: | Journal of Geophysical Research: Space Physics |
---|---|
Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
American Geophysical Union
2010
|
Subjects: | |
Online Access: | http://irep.ntu.ac.uk/id/eprint/27093/ http://irep.ntu.ac.uk/id/eprint/27093/1/PubSub4472_Wood.pdf https://doi.org/10.1029/2009JA014985 |
id |
ftnottinghtrentu:oai:irep.ntu.ac.uk:27093 |
---|---|
record_format |
openpolar |
spelling |
ftnottinghtrentu:oai:irep.ntu.ac.uk:27093 2023-05-15T18:29:50+02:00 Seasonal influence on polar cap patches in the high-latitude nightside ionosphere Wood, AG Pryse, SE 2010 text http://irep.ntu.ac.uk/id/eprint/27093/ http://irep.ntu.ac.uk/id/eprint/27093/1/PubSub4472_Wood.pdf https://doi.org/10.1029/2009JA014985 en eng American Geophysical Union http://irep.ntu.ac.uk/id/eprint/27093/1/PubSub4472_Wood.pdf WOOD, A.G. and PRYSE, S.E., 2010. Seasonal influence on polar cap patches in the high-latitude nightside ionosphere. Journal of Geophysical Research: Space Physics, 115 (A7), A07311. ISSN 0148-0227 doi:10.1029/2009JA014985 Article PeerReviewed 2010 ftnottinghtrentu https://doi.org/10.1029/2009JA014985 2022-01-09T07:06:46Z The influence of the season on the patch-to-background density ratio of polar cap patches in the nightside ionosphere was observed above northern Scandinavia around solar maximum (1999–2001). This is the first study of the seasonal effect in the nightside polar ionosphere. The observations were conducted by the European Incoherent Scatter Svalbard Radar under conditions favorable for patches based on the high-latitude plasma convection pattern, the interplanetary magnetic field, and an absence of in situ precipitation. Patch-to-background ratios of up to 9.4 ± 2.9 were observed between midwinter and equinox, with values of up to 1.9 ± 0.2 in summer. As the patch-to-background ratios in summer were <2, the enhancements could not formally be called patches; however, these were significant density enhancements within the antisunward cross-polar flow. Aberystwyth University's PLASLIFE (PLASma LIFEtime) computer simulation was used to model the observed seasonal trend in the patch-to-background ratio and to establish reasons for the difference between winter and summer values. This difference was primarily attributed to variation in the chemical composition of the atmosphere, which, in summer, both reduced the electron densities of the plasma drawn into the polar cap on the dayside and enhanced plasma loss by recombination. A secondary factor was the maintenance of the background polar ionosphere by photoionization in summer. Article in Journal/Newspaper Svalbard Nottingham Trent University's Institutional Repository (IRep) Midwinter ENVELOPE(139.931,139.931,-66.690,-66.690) Svalbard Journal of Geophysical Research: Space Physics 115 A7 |
institution |
Open Polar |
collection |
Nottingham Trent University's Institutional Repository (IRep) |
op_collection_id |
ftnottinghtrentu |
language |
English |
description |
The influence of the season on the patch-to-background density ratio of polar cap patches in the nightside ionosphere was observed above northern Scandinavia around solar maximum (1999–2001). This is the first study of the seasonal effect in the nightside polar ionosphere. The observations were conducted by the European Incoherent Scatter Svalbard Radar under conditions favorable for patches based on the high-latitude plasma convection pattern, the interplanetary magnetic field, and an absence of in situ precipitation. Patch-to-background ratios of up to 9.4 ± 2.9 were observed between midwinter and equinox, with values of up to 1.9 ± 0.2 in summer. As the patch-to-background ratios in summer were <2, the enhancements could not formally be called patches; however, these were significant density enhancements within the antisunward cross-polar flow. Aberystwyth University's PLASLIFE (PLASma LIFEtime) computer simulation was used to model the observed seasonal trend in the patch-to-background ratio and to establish reasons for the difference between winter and summer values. This difference was primarily attributed to variation in the chemical composition of the atmosphere, which, in summer, both reduced the electron densities of the plasma drawn into the polar cap on the dayside and enhanced plasma loss by recombination. A secondary factor was the maintenance of the background polar ionosphere by photoionization in summer. |
format |
Article in Journal/Newspaper |
author |
Wood, AG Pryse, SE |
spellingShingle |
Wood, AG Pryse, SE Seasonal influence on polar cap patches in the high-latitude nightside ionosphere |
author_facet |
Wood, AG Pryse, SE |
author_sort |
Wood, AG |
title |
Seasonal influence on polar cap patches in the high-latitude nightside ionosphere |
title_short |
Seasonal influence on polar cap patches in the high-latitude nightside ionosphere |
title_full |
Seasonal influence on polar cap patches in the high-latitude nightside ionosphere |
title_fullStr |
Seasonal influence on polar cap patches in the high-latitude nightside ionosphere |
title_full_unstemmed |
Seasonal influence on polar cap patches in the high-latitude nightside ionosphere |
title_sort |
seasonal influence on polar cap patches in the high-latitude nightside ionosphere |
publisher |
American Geophysical Union |
publishDate |
2010 |
url |
http://irep.ntu.ac.uk/id/eprint/27093/ http://irep.ntu.ac.uk/id/eprint/27093/1/PubSub4472_Wood.pdf https://doi.org/10.1029/2009JA014985 |
long_lat |
ENVELOPE(139.931,139.931,-66.690,-66.690) |
geographic |
Midwinter Svalbard |
geographic_facet |
Midwinter Svalbard |
genre |
Svalbard |
genre_facet |
Svalbard |
op_relation |
http://irep.ntu.ac.uk/id/eprint/27093/1/PubSub4472_Wood.pdf WOOD, A.G. and PRYSE, S.E., 2010. Seasonal influence on polar cap patches in the high-latitude nightside ionosphere. Journal of Geophysical Research: Space Physics, 115 (A7), A07311. ISSN 0148-0227 doi:10.1029/2009JA014985 |
op_doi |
https://doi.org/10.1029/2009JA014985 |
container_title |
Journal of Geophysical Research: Space Physics |
container_volume |
115 |
container_issue |
A7 |
_version_ |
1766213234151391232 |