Identification

Title

A simulation study on the relationship between field-aligned and field-perpendicular plasma velocities in the ionospheric F region

Abstract

This study addresses a long-standing scientific puzzle regarding ionospheric F-2 region dynamics. Incoherent scatter radar observations of F-2 region plasma drifts showed a strong anticorrelation between temporal variations of field-aligned upward plasma velocity (V-i parallel to) and field-perpendicular poleward plasma drift (V-i perpendicular to N) over time scales from a few hours to a day at middle latitudes. The underlying physical processes remain a highly controversial issue, despite a number of speculations and qualitative inspections. Previous studies lacked especially quantitative analysis that could lead to decisive conclusions. In this study, we provide a comprehensive modeling study to explore the physical processes relating V-i parallel to with V-i perpendicular to N variations using a self-consistent Thermosphere-Ionosphere-Electrodynamics General Circulation Model. It is found that the anticorrelation between V-i parallel to and V-i perpendicular to N has strong altitudinal and latitudinal dependences. The anticorrelation between the diurnal variations of V-i parallel to and V-i perpendicular to N is associated with the neutral wind dynamo. Poleward meridional winds result in downward V-i parallel to and poleward V-i perpendicular to N, and vice versa. The anticorrelation between short-term temporal disturbances of V-i parallel to and V-i perpendicular to N is mainly caused by ion drag, in response to high-latitude convection electric field forcing. This forcing penetrates to lower latitudes and affects poleward plasma drifts V-i perpendicular to N, which drags poleward meridional winds and modulates downward V-i parallel to. As the enhanced convection electric fields subside, the anticorrelation is mainly associated with disturbance meridional wind dynamo. The storm time high-latitude energy and momentum inputs change global meridional winds which modify zonal electric fields to induce V-i perpendicular to N changes. Furthermore, ambipolar diffusion plays a significant role in modulating the relationship between V-i parallel to and V-i perpendicular to N.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.org/ark:/85065/d741719t

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

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2020-01-08T00:00:00Z

Frequency of update

Quality and validity

Lineage

Conformity

Data format

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