Propagation of equatorial noise to low altitudes: Decoupling from the magnetosonic mode

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378289%3A_____%2F16%3A00462957" target="_blank" >RIV/68378289:_____/16:00462957 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11320/16:10334282

Výsledek na webu

<a href="http://dx.doi.org/10.1002/2016GL069582" target="_blank" >http://dx.doi.org/10.1002/2016GL069582</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1002/2016GL069582" target="_blank" >10.1002/2016GL069582</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Propagation of equatorial noise to low altitudes: Decoupling from the magnetosonic mode

Popis výsledku v původním jazyce

Equatorial noise (often phenomenologically described as magnetosonic waves in the literature) is a natural electromagnetic emission, which is generated by instability of ion distributions and which can interact with electrons in the Van Allen radiation belts. We use multicomponent electromagnetic measurements of the DEMETER spacecraft to investigate if equatorial noise propagates inward down to the Earth. Analysis of a selected event recorded under disturbed geomagnetic conditions shows that equatorial noise can be observed at an altitude of 700 km, while propagating radially downward as a superposition of spectral lines from different distant sources observed at frequencies both below and above the local proton cyclotron frequency. Changes in the local ion composition encountered by the waves during their inward propagation disconnect the identified wave mode from the low-frequency magnetosonic mode. The local ion composition also induces a cutoff which prevents the waves from propagating down to the ground.

Název v anglickém jazyce

Propagation of equatorial noise to low altitudes: Decoupling from the magnetosonic mode

Popis výsledku anglicky

Equatorial noise (often phenomenologically described as magnetosonic waves in the literature) is a natural electromagnetic emission, which is generated by instability of ion distributions and which can interact with electrons in the Van Allen radiation belts. We use multicomponent electromagnetic measurements of the DEMETER spacecraft to investigate if equatorial noise propagates inward down to the Earth. Analysis of a selected event recorded under disturbed geomagnetic conditions shows that equatorial noise can be observed at an altitude of 700 km, while propagating radially downward as a superposition of spectral lines from different distant sources observed at frequencies both below and above the local proton cyclotron frequency. Changes in the local ion composition encountered by the waves during their inward propagation disconnect the identified wave mode from the low-frequency magnetosonic mode. The local ion composition also induces a cutoff which prevents the waves from propagating down to the ground.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

BL - Fyzika plasmatu a výboje v plynech

OECD FORD obor

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Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2016

Kód důvěrnosti údajů

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

Název periodika

Geophysical Research Letters

ISSN

0094-8276

e-ISSN

—

Svazek periodika

43

Číslo periodika v rámci svazku

13

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

11

Strana od-do

6694-6704

Kód UT WoS článku

000380901600003

EID výsledku v databázi Scopus

2-s2.0-84978139103