Tenuous solar winds: Insights on solar wind-magnetosphere interactions

During solar cycle 23 quasi-dropouts of the solar wind (density < 1 cm- 3) were observed. These tenuous winds allow us to probe properties of the magnetosphere and its coupling to the solar wind which would otherwise be obscured by the effect of high density. We focus on five areas which prov...

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Autores principales: Farrugia, C.J., Gratton, F.T., Jordanova, V.K., Matsui, H., Mühlbachler, S., Torbert, R.B., Ogilvie, K.W., Singer, H.J.
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_13646826_v70_n2-4_p371_Farrugia
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spelling todo:paper_13646826_v70_n2-4_p371_Farrugia2023-10-03T16:11:14Z Tenuous solar winds: Insights on solar wind-magnetosphere interactions Farrugia, C.J. Gratton, F.T. Jordanova, V.K. Matsui, H. Mühlbachler, S. Torbert, R.B. Ogilvie, K.W. Singer, H.J. Dayside erosion Low density solar wind Magnetosheath waves Quiet-time ring current constants Electromagnetic waves Geomagnetism Magnetic anisotropy Magnetic fields Magnetosphere Statistics Magnetosheath wave Ring current constant Solar wind During solar cycle 23 quasi-dropouts of the solar wind (density < 1 cm- 3) were observed. These tenuous winds allow us to probe properties of the magnetosphere and its coupling to the solar wind which would otherwise be obscured by the effect of high density. We focus on five areas which provided new insights into the response of geospace to solar wind variations: (i) the magnetospheric magnetic configuration; (ii) the polar rain; (iii) dayside flux erosion; (iv) magnetosheath waves; and (v) ring current constants. We find: (i) the geostationary field had dipolar strength and was inclined by ≤ 5{ring operator} to the dipolar direction; (ii) the solar wind strahl, and consequently the polar rain, were intensified; (iii) the depression of the geostationary field (Δ BGS) due to dayside flux erosion could be measured and was related to IMF Bz by Δ BGS = - 2.8 + 2.3 Bz (nT); (iv) right-hand electromagnetic ion cyclotron waves were excited alone in the magnetosheath and were generated directly from the temperature anisotropy of the solar wind; (v) ring and magnetopause currents decreased to asymptotic values of 5 and 3 nT, respectively, which are substantially smaller than quiet-time values obtained from statistics. © 2007 Elsevier Ltd. All rights reserved. Fil:Gratton, F.T. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_13646826_v70_n2-4_p371_Farrugia
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Dayside erosion
Low density solar wind
Magnetosheath waves
Quiet-time ring current constants
Electromagnetic waves
Geomagnetism
Magnetic anisotropy
Magnetic fields
Magnetosphere
Statistics
Magnetosheath wave
Ring current constant
Solar wind
spellingShingle Dayside erosion
Low density solar wind
Magnetosheath waves
Quiet-time ring current constants
Electromagnetic waves
Geomagnetism
Magnetic anisotropy
Magnetic fields
Magnetosphere
Statistics
Magnetosheath wave
Ring current constant
Solar wind
Farrugia, C.J.
Gratton, F.T.
Jordanova, V.K.
Matsui, H.
Mühlbachler, S.
Torbert, R.B.
Ogilvie, K.W.
Singer, H.J.
Tenuous solar winds: Insights on solar wind-magnetosphere interactions
topic_facet Dayside erosion
Low density solar wind
Magnetosheath waves
Quiet-time ring current constants
Electromagnetic waves
Geomagnetism
Magnetic anisotropy
Magnetic fields
Magnetosphere
Statistics
Magnetosheath wave
Ring current constant
Solar wind
description During solar cycle 23 quasi-dropouts of the solar wind (density < 1 cm- 3) were observed. These tenuous winds allow us to probe properties of the magnetosphere and its coupling to the solar wind which would otherwise be obscured by the effect of high density. We focus on five areas which provided new insights into the response of geospace to solar wind variations: (i) the magnetospheric magnetic configuration; (ii) the polar rain; (iii) dayside flux erosion; (iv) magnetosheath waves; and (v) ring current constants. We find: (i) the geostationary field had dipolar strength and was inclined by ≤ 5{ring operator} to the dipolar direction; (ii) the solar wind strahl, and consequently the polar rain, were intensified; (iii) the depression of the geostationary field (Δ BGS) due to dayside flux erosion could be measured and was related to IMF Bz by Δ BGS = - 2.8 + 2.3 Bz (nT); (iv) right-hand electromagnetic ion cyclotron waves were excited alone in the magnetosheath and were generated directly from the temperature anisotropy of the solar wind; (v) ring and magnetopause currents decreased to asymptotic values of 5 and 3 nT, respectively, which are substantially smaller than quiet-time values obtained from statistics. © 2007 Elsevier Ltd. All rights reserved.
format JOUR
author Farrugia, C.J.
Gratton, F.T.
Jordanova, V.K.
Matsui, H.
Mühlbachler, S.
Torbert, R.B.
Ogilvie, K.W.
Singer, H.J.
author_facet Farrugia, C.J.
Gratton, F.T.
Jordanova, V.K.
Matsui, H.
Mühlbachler, S.
Torbert, R.B.
Ogilvie, K.W.
Singer, H.J.
author_sort Farrugia, C.J.
title Tenuous solar winds: Insights on solar wind-magnetosphere interactions
title_short Tenuous solar winds: Insights on solar wind-magnetosphere interactions
title_full Tenuous solar winds: Insights on solar wind-magnetosphere interactions
title_fullStr Tenuous solar winds: Insights on solar wind-magnetosphere interactions
title_full_unstemmed Tenuous solar winds: Insights on solar wind-magnetosphere interactions
title_sort tenuous solar winds: insights on solar wind-magnetosphere interactions
url http://hdl.handle.net/20.500.12110/paper_13646826_v70_n2-4_p371_Farrugia
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