Evolution of the magnetic field structure outside the magnetopause under radial IMF conditions

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F17%3A10371408" target="_blank" >RIV/00216208:11320/17:10371408 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1002/2015JA021809" target="_blank" >http://dx.doi.org/10.1002/2015JA021809</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1002/2015JA021809" target="_blank" >10.1002/2015JA021809</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Evolution of the magnetic field structure outside the magnetopause under radial IMF conditions

Popis výsledku v původním jazyce

We use the Time History of Events and Macroscale Interactions during Substorms data to investigate the magnetic field structure just outside the magnetopause and its time evolution for radial interplanetary magnetic field (IMF) events. When the magnetic field drapes around the magnetopause in the magnetosheath region, an asymmetric magnetic field orientation in different hemispheres is expected. Our two-case study reveals some conflicts with the predicted draped field configuration in the Southern Hemisphere. The magnetosheath B-z component had a different sign depending on the upstream IMF B-x component&apos;s polarity at the beginning of the radial IMF intervals. With time, the observed B-z became northward in both cases with increasing positive values through the events. The increasing value of the B-z component may be explained by two possible mechanisms: by a change of the upstream IMF and by a reconnection between magnetosheath and magnetospheric field lines. Our study shows that both mechanisms contributed to the observed changes. Thus, there was a correlation between the change of the upstream IMF conditions and an increase in the magnetosheath northward magnetic field component. The observed formation of the boundary layer near the magnetopause proves that the reconnection process was ongoing at least for a part of the time. We suggest two possible reconnection scenarios: one near subsolar point and another tailward of the one cusp due to lobe reconnection. The asymmetry of reconnection locations causes rearrangement of the magnetic field structure near the magnetopause and turns the observed magnetosheath B-z component even further into positive values.

Název v anglickém jazyce

Evolution of the magnetic field structure outside the magnetopause under radial IMF conditions

Popis výsledku anglicky

We use the Time History of Events and Macroscale Interactions during Substorms data to investigate the magnetic field structure just outside the magnetopause and its time evolution for radial interplanetary magnetic field (IMF) events. When the magnetic field drapes around the magnetopause in the magnetosheath region, an asymmetric magnetic field orientation in different hemispheres is expected. Our two-case study reveals some conflicts with the predicted draped field configuration in the Southern Hemisphere. The magnetosheath B-z component had a different sign depending on the upstream IMF B-x component&apos;s polarity at the beginning of the radial IMF intervals. With time, the observed B-z became northward in both cases with increasing positive values through the events. The increasing value of the B-z component may be explained by two possible mechanisms: by a change of the upstream IMF and by a reconnection between magnetosheath and magnetospheric field lines. Our study shows that both mechanisms contributed to the observed changes. Thus, there was a correlation between the change of the upstream IMF conditions and an increase in the magnetosheath northward magnetic field component. The observed formation of the boundary layer near the magnetopause proves that the reconnection process was ongoing at least for a part of the time. We suggest two possible reconnection scenarios: one near subsolar point and another tailward of the one cusp due to lobe reconnection. The asymmetry of reconnection locations causes rearrangement of the magnetic field structure near the magnetopause and turns the observed magnetosheath B-z component even further into positive values.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10305 - Fluids and plasma physics (including surface physics)

Projekt

<a href="/cs/project/GA17-06065S" target="_blank" >GA17-06065S: Variace slunečního větru a jejich vazba na dynamiku magnetosféry Země</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Geophysical Research: Space Physics

ISSN

2169-9380

e-ISSN

—

Svazek periodika

122

Číslo periodika v rámci svazku

4

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

13

Strana od-do

4051-4063

Kód UT WoS článku

000401340800014

EID výsledku v databázi Scopus

2-s2.0-85017336079