Signature of Y-forking in ionogram traces observed at low-mid latitude Indian station, New Delhi, during the earthquake events of 2020: ionosonde observations

Frontiers in Astronomy and Space Sciences

Astronomy and Space Sciences

Qadeer Ahmed¹  Arti Bhardwaj¹  Anshul Singh¹  Ankit Gupta¹  A. K. Upadhayaya²  M. V. Sunil Krishna³  S. Sarkhel³  Sumedha Gupta⁴  Duggirala Pallamraju⁵  Tarun Pant⁶ 

[1] Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India;CSIR-National Physical Laboratory, Environmental Science and Biomedical Metrology Division, New Delhi, India;CSIR-National Physical Laboratory, Environmental Science and Biomedical Metrology Division, New Delhi, India;Department of Physics, Indian Institute of Technology Roorkee, Roorkee, India;Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO, United States;Physical Research Laboratory, Ahmedabad, India;Space Physics Laboratory, Vikram Sarabhai Space Centre, Trivandrum, India;

关键词: Y-forking;    precursor;    TIDs;    digisonde;    electron density;   

DOI  :  10.3389/fspas.2023.1170288

 received in 2023-02-20, accepted in 2023-07-18,  发布年份 2023

来源: Frontiers

【 摘 要 】

We have examined ionospheric response to eleven earthquake events measuring less than four on the Richter scale during the year 2020 that occurred in the vicinity of New Delhi (28.6°N, 77.2°E, 42.4°N dip). We have used ionogram traces, manually scaled critical ionospheric layer parameters using SAO explorer obtained from Digisonde along with the O(1D) airglow observations from a multi-wavelength all-sky airglow imager installed at Hanle, Ladakh, India (32.7°N, 78.9°E, 24.1°N dip). Perceptible ionospheric perturbations 2–9 days prior to these earthquake events resulting in more than 250% variation in electron density are observed. We found distortion of ionogram trace in the form of Y forking majorly at New Delhi on the precursor day and after the earthquake event. Traces of Y forked ionograms were also observed at Ahmedabad (23°N, 72°E, 15°N dip) and Trivandrum (8.5°N, 76.9°E, 0.5°N dip). These Y-forked ionograms are one of the first observations during any earthquake events and are looked at as a signature of Travelling Ionospheric Disturbances (TIDs).

【 授权许可】

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Copyright © 2023 Bhardwaj, Gupta, Ahmed, Singh, Gupta, Sarkhel, Sunil Krishna, Pallamraju, Pant and Upadhayaya.