Title: Lightning Interferometry Uncertainty, Beam Steering Interferometry, and Evidence of Lightning Being Ignited by a Cosmic Ray Shower

Abstract

Abstract We present an uncertainty analysis on correlation‐based time delay estimate, the basis for broadband lightning interferometry. A normal interferometry would yield much higher uncertainties than the theoretically predicted lower bound due to finite correlation window lengths. However, if the signals are aligned in time, the uncertainties approach the lower bound and can be used to indicate the interferometric uncertainties. Based on this, we introduce a beam steering interferometry technique. It first estimates a direction centroid for the lightning sources with a normal interferometry and computes the time delays among the signals. It then shifts the raw data with the time delays to align the signals roughly in time and reprocess the aligned signals. It finally pushes the reprocessed results to their correct positions, based on the time delays estimated in the first step. We apply this technique on a fast positive breakdown (FPB) process that started a normal intracloud lightning. The FPB process is shown to have a much more complex structure and development than a normal interferometry would provide. More importantly, from both interferometric and polarization analyses, the FPB appears to be ignited by a cosmic ray shower (CRS). We estimate the radio frequency strength and frequency contentmore » related to a presumed CRS in a thunderstorm electric field and find that they are in agreement with the observations. We examine the electric field effect of the CRS front and find that it could raise the field above the threshold for positive breakdown and is capable of igniting the FPB (and the lightning).« less

Authors:

Shao, Xuan‐Min  ^[1];

• Search DOE PAGES for author "Shao, Xuan‐Min"
• Search DOE PAGES for ORCID "0000-0002-6159-7918"

Ho, Cheng ^[1]; Bowers, Gregory  ^[1];

• Search DOE PAGES for author "Bowers, Gregory"
• Search DOE PAGES for ORCID "0000-0002-9524-2234"

Blaine, William  ^[1];

• Search DOE PAGES for author "Blaine, William"
• Search DOE PAGES for ORCID "0000-0001-9231-8718"

Dingus, Brenda ^[1]

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+ Show Author Affiliations

1. Los Alamos National Laboratory Los Alamos NM USA

Publication Date:

Mon Oct 05 00:00:00 EDT 2020

Sponsoring Org.:

USDOE

OSTI Identifier:

1670484

Alternate Identifier(s):

OSTI ID: 1786822

Resource Type:

Published Article

Journal Name:

Journal of Geophysical Research: Atmospheres

Additional Journal Information:

Journal Name: Journal of Geophysical Research: Atmospheres Journal Volume: 125 Journal Issue: 19; Journal ID: ISSN 2169-897X

Publisher:

American Geophysical Union (AGU)

Country of Publication:

United States

Language:

English