Statistical Observations in Support of Bow Shock Current Closure to Earth's High-Latitude Ionosphere During Non-Zero IMF By
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F25%3A10510437" target="_blank" >RIV/00216208:11320/25:10510437 - isvavai.cz</a>
Result on the web
<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=-DE-tO5aig" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=-DE-tO5aig</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1029/2024JA033599" target="_blank" >10.1029/2024JA033599</a>
Alternative languages
Result language
angličtina
Original language name
Statistical Observations in Support of Bow Shock Current Closure to Earth's High-Latitude Ionosphere During Non-Zero IMF By
Original language description
The bow shock current (BSC) plays an important role in supplying the magnetosphere with solar wind energy, in particular during times of low solar wind magnetosonic Mach numbers. Since the magnetic pile-up in the magnetosheath has to be maintained, the BSC cannot close locally, but must instead connect to magnetospheric current systems. However, the details of this closure remain poorly understood. For east-west interplanetary magnetic field (IMF) it has been hypothesized that the BSC partly closes to the high-latitude ionosphere, as field-aligned currents (FACs) on open field lines, but there is still no statistical evidence of this. In order to investigate this hypothesis, we use 9 years of Defense Meteorological Satellite Program (DMSP) data to construct normalized FAC maps of the northern hemisphere polar cap. We sort them according to different IMF clock angles, IMF magnitudes and magnetosonic Mach numbers. By separating opposite polarity FACs, we show that, on average, a unipolar FAC exists in the dayside polar cap when the IMF B-y not equal 0, regardless of the sign of the IMF B-z. This current flows out of (into) the ionosphere in the northern hemisphere for IMF B-y>0 (<0) and is thus of the correct polarity to connect to the north-south component of the BSC. Moreover, it is strongest when the BSC flows predominantly in the north-south direction. These results constitute the first statistical evidence in support of at least a partial closure of the BSC to the ionosphere during non-zero IMF B-y.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10305 - Fluids and plasma physics (including surface physics)
Result continuities
Project
<a href="/en/project/GA21-26463S" target="_blank" >GA21-26463S: Magnetopause processes, their drivers and consequences</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2025
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Journal of Geophysical Research. Space Physics
ISSN
2169-9380
e-ISSN
2169-9402
Volume of the periodical
130
Issue of the periodical within the volume
6
Country of publishing house
US - UNITED STATES
Number of pages
18
Pages from-to
e2024JA033599
UT code for WoS article
001499454500001
EID of the result in the Scopus database
2-s2.0-105007810765