Equatorial noise emissions observed by the DEMETER spacecraft during geomagnetic storms

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378289%3A_____%2F16%3A00467942" target="_blank" >RIV/68378289:_____/16:00467942 - isvavai.cz</a>

Alternative codes found

RIV/00216208:11320/16:10334394

Result on the web

<a href="http://dx.doi.org/10.1002/2016JA023145" target="_blank" >http://dx.doi.org/10.1002/2016JA023145</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1002/2016JA023145" target="_blank" >10.1002/2016JA023145</a>

Result language

angličtina

Original language name

Equatorial noise emissions observed by the DEMETER spacecraft during geomagnetic storms

Original language description

Equatorial noise emissions are electromagnetic waves routinely observed in the equatorial region of the inner magnetosphere at frequencies between the proton cyclotron frequency and the lower hybrid frequency. Their observations are, however, typically limited to radial distances larger than about 2RE. We use the data measured by the low-altitude DEMETER spacecraft (altitude of about 700 km) to confirm that during periods of enhanced geomagnetic activity, these emissions penetrate down to low radial distances and eventually become a dominant wave emission close to the proton cyclotron frequency in the equatorial region. Wave data obtained during six intense geomagnetic storms (Dst < 100 nT) are analyzed. It is shown that during the analyzed time intervals, the daytime wave activity within about 20° from the geomagnetic equator is significantly enhanced, while the nightside wave activity shows a weaker increase at lower frequencies. Multicomponent wave data allow us to determine dayside wave propagation parameters. It is shown that the waves are nearly linearly polarized and their wave vector directions are almost perpendicular to the ambient Earth's magnetic field, as it has been previously observed for equatorial noise emissions. Finally, we analyze the dependence of the equatorial wave intensity at the proton cyclotron frequency on Dst and AE geomagnetic indices, and we demonstrate that the dayside wave intensity increases by as much as 3 orders of magnitude during severely disturbed periods.

Czech name

—

Czech description

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Type

J_x - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)

CEP classification

BL - Plasma physics and discharge through gases

OECD FORD branch

—

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2016

Confidentiality

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

Name of the periodical

Journal of Geophysical Research: Space Physics

ISSN

2169-9380

e-ISSN

—

Volume of the periodical

121

Issue of the periodical within the volume

10

Country of publishing house

US - UNITED STATES

Number of pages

14

Pages from-to

9744-9757

UT code for WoS article

000388965900029

EID of the result in the Scopus database

2-s2.0-84991608267