Affiliation:
1. Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, North Carolina 27695, USA
Abstract
There has been increased interest in improving severe weather detection by supplementing the conventional operational radar network with an infrasound observation network, which may be able to detect distinct sub-audible signatures from tornadic supercells. While there is evidence that tornadic thunderstorms exhibit observable infrasound signals, what is not well-understood is whether these infrasound signals are unique to tornadic supercells (compared to nontornadic supercells) or whether there is useful signal prior to tornadogenesis, which would be most relevant to forecasters. Using simulations of supercells, tailored to represent acoustic waves with frequencies from 0.1 to 2 Hz, spectral analysis reveals that both nontornadic and pre-tornadic supercells produce strikingly similar sound pressure levels at the surface, even in close spatial proximity to the storms (less than 20 km). Sensitivity tests employing varying microphysics schemes also show similar acoustic emissions between supercells. Riming of supercooled water droplets in the upper-troposphere is the sole mechanism generating high-frequency pressure waves in supercells prior to tornadogenesis or during tornadogenesis-failure; however, riming occurs continuously in mature nontornadic and tornadic supercells. Our simulations found no clear evidence that infrasound produced by supercells prior to tornado formation (compared to nontornadic supercells) is sufficiently distinct to improve lead-time of tornado warnings.
Publisher
Acoustical Society of America (ASA)
Subject
Acoustics and Ultrasonics,Arts and Humanities (miscellaneous)
Cited by
4 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献