Observations of the solar wind-magnetosphere-ionosphere coupling
In this thesis, the solar wind-magnetosphere-ionosphere coupling is studied observationally, with the main focus on the ionospheric currents in the auroral region. The thesis consists of five research articles and an introductory part that summarises the most important results reached in the article...
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ftunivhelsihelda:oai:helda.helsinki.fi:10138/23115 2023-08-20T04:06:15+02:00 Observations of the solar wind-magnetosphere-ionosphere coupling Havaintoja aurinkotuulen, magnetosfäärin ja ionosfäärin kytkennästä Juusola, Liisa Lester, Mark University of Helsinki, Faculty of Science, Department of Physics Ilmatieteen laitos Helsingin yliopisto, matemaattis-luonnontieteellinen tiedekunta, fysiikan laitos Helsingfors universitet, matematisk-naturvetenskapliga fakulteten, institutionen för fysik Amm, Olaf Kauristie, Kirsti 2010-11-25T14:07:39Z application/pdf http://hdl.handle.net/10138/23115 eng eng Helsingin yliopisto Helsingfors universitet University of Helsinki URN:ISBN:978-951-697-691-7 Helsinki: Yliopistopaino, 2009, Finnish Meteorological Institute Contributions. 0782-6117 http://hdl.handle.net/10138/23115 URN:ISBN:978-951-697-692-4 Julkaisu on tekijänoikeussäännösten alainen. Teosta voi lukea ja tulostaa henkilökohtaista käyttöä varten. Käyttö kaupallisiin tarkoituksiin on kielletty. This publication is copyrighted. You may download, display and print it for Your own personal use. Commercial use is prohibited. Publikationen är skyddad av upphovsrätten. Den får läsas och skrivas ut för personligt bruk. Användning i kommersiellt syfte är förbjuden. fysiikka Text Doctoral dissertation (article-based) Artikkeliväitöskirja Artikelavhandling doctoralThesis 2010 ftunivhelsihelda 2023-07-28T06:07:07Z In this thesis, the solar wind-magnetosphere-ionosphere coupling is studied observationally, with the main focus on the ionospheric currents in the auroral region. The thesis consists of five research articles and an introductory part that summarises the most important results reached in the articles and places them in a wider context within the field of space physics. Ionospheric measurements are provided by the International Monitor for Auroral Geomagnetic Effects (IMAGE) magnetometer network, by the low-orbit CHAllenging Minisatellite Payload (CHAMP) satellite, by the European Incoherent SCATter (EISCAT) radar, and by the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) satellite. Magnetospheric observations, on the other hand, are acquired from the four spacecraft of the Cluster mission, and solar wind observations from the Advanced Composition Explorer (ACE) and Wind spacecraft. Within the framework of this study, a new method for determining the ionospheric currents from low-orbit satellite-based magnetic field data is developed. In contrast to previous techniques, all three current density components can be determined on a matching spatial scale, and the validity of the necessary one-dimensionality approximation, and thus, the quality of the results, can be estimated directly from the data. The new method is applied to derive an empirical model for estimating the Hall-to-Pedersen conductance ratio from ground-based magnetic field data, and to investigate the statistical dependence of the large-scale ionospheric currents on solar wind and geomagnetic parameters. Equations describing the amount of field-aligned current in the auroral region, as well as the location of the auroral electrojets, as a function of these parameters are derived. Moreover, the mesoscale (10-1000 km) ionospheric equivalent currents related to two magnetotail plasma sheet phenomena, bursty bulk flows and flux ropes, are studied. Based on the analysis of 22 events, the typical equivalent current pattern related to bursty ... Doctoral or Postdoctoral Thesis EISCAT Helsingfors Universitet: HELDA – Helsingin yliopiston digitaalinen arkisto Pedersen ENVELOPE(140.013,140.013,-66.668,-66.668) |
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Helsingfors Universitet: HELDA – Helsingin yliopiston digitaalinen arkisto |
op_collection_id |
ftunivhelsihelda |
language |
English |
topic |
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fysiikka Juusola, Liisa Observations of the solar wind-magnetosphere-ionosphere coupling |
topic_facet |
fysiikka |
description |
In this thesis, the solar wind-magnetosphere-ionosphere coupling is studied observationally, with the main focus on the ionospheric currents in the auroral region. The thesis consists of five research articles and an introductory part that summarises the most important results reached in the articles and places them in a wider context within the field of space physics. Ionospheric measurements are provided by the International Monitor for Auroral Geomagnetic Effects (IMAGE) magnetometer network, by the low-orbit CHAllenging Minisatellite Payload (CHAMP) satellite, by the European Incoherent SCATter (EISCAT) radar, and by the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) satellite. Magnetospheric observations, on the other hand, are acquired from the four spacecraft of the Cluster mission, and solar wind observations from the Advanced Composition Explorer (ACE) and Wind spacecraft. Within the framework of this study, a new method for determining the ionospheric currents from low-orbit satellite-based magnetic field data is developed. In contrast to previous techniques, all three current density components can be determined on a matching spatial scale, and the validity of the necessary one-dimensionality approximation, and thus, the quality of the results, can be estimated directly from the data. The new method is applied to derive an empirical model for estimating the Hall-to-Pedersen conductance ratio from ground-based magnetic field data, and to investigate the statistical dependence of the large-scale ionospheric currents on solar wind and geomagnetic parameters. Equations describing the amount of field-aligned current in the auroral region, as well as the location of the auroral electrojets, as a function of these parameters are derived. Moreover, the mesoscale (10-1000 km) ionospheric equivalent currents related to two magnetotail plasma sheet phenomena, bursty bulk flows and flux ropes, are studied. Based on the analysis of 22 events, the typical equivalent current pattern related to bursty ... |
author2 |
Lester, Mark University of Helsinki, Faculty of Science, Department of Physics Ilmatieteen laitos Helsingin yliopisto, matemaattis-luonnontieteellinen tiedekunta, fysiikan laitos Helsingfors universitet, matematisk-naturvetenskapliga fakulteten, institutionen för fysik Amm, Olaf Kauristie, Kirsti |
format |
Doctoral or Postdoctoral Thesis |
author |
Juusola, Liisa |
author_facet |
Juusola, Liisa |
author_sort |
Juusola, Liisa |
title |
Observations of the solar wind-magnetosphere-ionosphere coupling |
title_short |
Observations of the solar wind-magnetosphere-ionosphere coupling |
title_full |
Observations of the solar wind-magnetosphere-ionosphere coupling |
title_fullStr |
Observations of the solar wind-magnetosphere-ionosphere coupling |
title_full_unstemmed |
Observations of the solar wind-magnetosphere-ionosphere coupling |
title_sort |
observations of the solar wind-magnetosphere-ionosphere coupling |
publisher |
Helsingin yliopisto |
publishDate |
2010 |
url |
http://hdl.handle.net/10138/23115 |
long_lat |
ENVELOPE(140.013,140.013,-66.668,-66.668) |
geographic |
Pedersen |
geographic_facet |
Pedersen |
genre |
EISCAT |
genre_facet |
EISCAT |
op_relation |
URN:ISBN:978-951-697-691-7 Helsinki: Yliopistopaino, 2009, Finnish Meteorological Institute Contributions. 0782-6117 http://hdl.handle.net/10138/23115 URN:ISBN:978-951-697-692-4 |
op_rights |
Julkaisu on tekijänoikeussäännösten alainen. Teosta voi lukea ja tulostaa henkilökohtaista käyttöä varten. Käyttö kaupallisiin tarkoituksiin on kielletty. This publication is copyrighted. You may download, display and print it for Your own personal use. Commercial use is prohibited. Publikationen är skyddad av upphovsrätten. Den får läsas och skrivas ut för personligt bruk. Användning i kommersiellt syfte är förbjuden. |
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1774717228842745856 |