Programme

O.18 -- Oral, VCTP-45

Date: Wednesday, 14 October 2020

Time: 11:40 - 12:00

Online presentation

Probing atmospheric electric fields under thunderstorm conditions by using radio emission from extensive air showers

Trinh Thi Ngoc Gia (1), Olaf Scholten (2), LOFAR KCP group (3)

(1) Physics Education Department, School of Education, Can Tho University, Can Tho City, Vietnam; (2) KVI-CART, University of Groningen, The Netherlands; (3) Department of Astrophysics/IMAPP, Radboud University Nijmegen, The Netherlands

Energetic cosmic rays impinging on the atmosphere create a particle avalanche called an extensive air shower. In the leading plasma of this shower electric currents are induced that generate radio waves. During thunderstorms, radio emission from extensive air showers are influenced by atmospheric electric fields. These effects are observed at LOw Frequency ARray (LOFAR) radio telescope. We observe large differences in the intensity and polarization patterns of showers measured during thunderstorm conditions from the ones measured during fair-weather conditions. Thus, radio emission from air showers can be used as a tool to determine atmospheric electric fields. We show that the atmospheric electric fields are usually composed out of three layers. The height of the bottom layer near the ground depends on the seasons and large horizontal electric fields are observed. Acknowledgement: This research is funded by the Vietnam National Foundation for Science and Technology Development (NAFOSTED) under Grant 103.01-2019.378. The LOFAR Cosmic Ray Key Science Project acknowledges funding from an Advanced Grant of the European Research Council (ERC)(FP/2007-2013)/ERC Grant Agreement No. 227610.

Presenter: Trinh Thi Ngoc Gia