A Study on Low Frequency Electromagnetic Cyclotron Waves in the Solar Wind

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F22%3A10457961" target="_blank" >RIV/00216208:11320/22:10457961 - isvavai.cz</a>

Result on the web

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=ELXwp43HFH" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=ELXwp43HFH</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/1674-4527/ac67bc" target="_blank" >10.1088/1674-4527/ac67bc</a>

Result language

angličtina

Original language name

A Study on Low Frequency Electromagnetic Cyclotron Waves in the Solar Wind

Original language description

According to Wind observations between 2005 and 2015, this paper investigates the dependences of the occurrence of low frequency electromagnetic cyclotron waves (ECWs) on the plasma parameters, the solar cycle, and the orientations of alpha-proton drift velocity ( V ( d )) and the ambient magnetic field ( B ). The occurrence rates of ECWs with respect to six plasma parameters are calculated. Results show that the preferential conditions for generation of left-handed (LH) ECWs are higher proton temperature (T ( p )), higher proton velocity (V ( p )), lower proton density (N ( p )), stronger proton temperature anisotropy (T (perpendicular to)/T (parallel to)), higher normalized alpha-proton drift velocity (V ( d )/V (A)), and higher normalized alpha particle density (N ( alpha )/N ( p )), where T (perpendicular to) and T (parallel to) refer to proton temperatures perpendicular and parallel to B , and V (A) is the local Alfven velocity. For right-handed (RH) ECWs, however, the dependences on these plasma parameters are not obvious. On the other hand, it is found that the occurrence rate of LH ECWs increases as the sunspot number decreases, and decreases as the sunspot number increases. Further investigation shows that the increased occurrence rate of LH ECWs is accompanied by an increase in the medians of V ( p ), V ( d )/V (A), and N ( alpha )/N ( p ). For RH ECWs, the occurrence rate appears to be nearly unrelated to the sunspot number, suggesting a negligible correlation with the solar cycle. In addition, a modified angle is introduced to include the factors of orientation of B (anti-sunward or sunward) and angle between V ( d ) and B , simultaneously. It is found that the occurrence of LH ECWs has the strong preferential condition that V ( d ) is anti-sunward, while a different situation arises for RH ECWs. These results are discussed in the context of the temperature-anisotropy-driven instabilities with the effect of alpha particles.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10305 - Fluids and plasma physics (including surface physics)

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2022

Confidentiality

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

Name of the periodical

Research in Astronomy and Astrophysics

ISSN

1674-4527

e-ISSN

2397-6209

Volume of the periodical

22

Issue of the periodical within the volume

6

Country of publishing house

CN - CHINA

Number of pages

9

Pages from-to

065007

UT code for WoS article

000805141500001

EID of the result in the Scopus database

2-s2.0-85131448754