Identification

Title

Weak Solar Radio Bursts from the solar wind acceleration region observed by the Parker Solar Probe and its probable emission mechanism

Abstract

The Parker Solar Probe (PSP) provides us with an unprecedentedly close approach to the observation of the Sun and hence the possibility of directly understanding the elementary process that occurs on the kinetic scale of particles' collective interaction in solar coronal plasmas. We report a type of weak solar radio burst (SRB) that was detected by PSP when it passed a low-density magnetic channel during its second encounter phase. These weak SRBs have a low starting frequency of similar to 20 MHz and a narrow frequency range from a few tens of MHz to a few hundred kHz. Their dynamic spectra display a strongly evolving feature of the intermediate relative drift rate decreasing rapidly from above 0.01 s(-1) to below 0.01 s(-1). Analyses based on common empirical models of solar coronal plasmas indicate that these weak SRBs originate from a heliocentric distance of similar to 1.1-6.1 R-S (the solar radius), a typical solar wind acceleration region with a low-beta plasma, and that their sources have a typical motion velocity of similar to v(A) (Alfven velocity) obviously lower than that of the fast electrons required to effectively excite SRBs. We propose that solitary kinetic Alfven waves with kinetic scales could be responsible for the generation of these small-scale weak SRBs, called solitary wave radiation.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.org/ark:/85065/d7xs60hf

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

Geographic location

West bounding longitude

East bounding longitude

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South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2024-01-01T00:00:00Z

Frequency of update

Quality and validity

Lineage

Conformity

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name of format

version of format

Constraints related to access and use

Constraint set

Use constraints

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact