Identification

Title

Responses of the daytime low and equatorial ionosphere and thermosphere over the Indian region during the geomagnetic storm of April 2023

Abstract

Study of the response of Thermosphere–Ionosphere (TI) system over the Indian longitude sector during the geomagnetic storm of April 23–24, 2023, is presented. The ionosonde observations at the dip equatorial station, Trivandrum (8.52°N, 77°E, dip lat. = 1.96°N), are found to have unusually high F2 peak plasma density (foF2), with three maxima during the daytime on April 24. The Total Electron Content (TEC) observations from different latitudes showed enhancements temporally progressing from north to south. These features are identified as Traveling Ionospheric Disturbances (TIDs) with speeds ∼400 to 750 m/s. Two major enhancements in TEC observed over Trivandrum were concurrent to the first and third maxima in foF2. Simulations of meridional wind and temperature for this storm were carried out using the Thermosphere–Ionosphere–Electrodynamics General Circulation Model (TIEGCM) that was driven with high‐latitude inputs derived from the Assimilative Mapping of Ionospheric Electrodynamics (AMIE) technique. Simulations show the signatures of Traveling Atmospheric Disturbances (TADs) in ionospheric F‐region, which conform with the TID observations. The second foF2 peak is found to be simultaneous to the modulation in Prompt Penetration Electric Field (PPEF), which is also observed in the drift of the E‐region ionospheric plasma irregularities using an HF radar and the Equatorial Electrojet (EEJ) strength measured by ground‐based magnetometer. Simultaneously increasing electric field and foF2 implies the presence of storm‐time equatorward wind, inhibiting the plasma fountain. This is the first report comparing comprehensive observations and AMIE‐TIEGCM modeling studies of daytime responses of low and equatorial TI during a geomagnetic storm.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.net/ark:/85065/d77p93tm

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

2025-03-01T00:00:00Z

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