Multiyear validation of the NRL-G2S wind fields using infrasound from Yasur

Abstract

The Yasur volcano in the Vanuatu archipelago is an outstanding source of infrasonic waves due to its regular activity. This volcano is permanently monitored by the IS22 infrasound station located in New Caledonia, about 400 km from it, and by one microbarometer installed close to its crater. A multiyear monitoring of Yasur is proposed to validate consistently the Naval Research Laboratory Ground to Space (NRL-G2S) semiempirical atmospheric model up to the stratosphere. The results of propagation modeling accurately explain seasonal changes as well as small short-timescale variations of the infrasonic observables. The azimuthal deviation is predicted with an uncertainty in general lower than 0.5°. The fluctuations of the trace velocity and the celerity are simulated with errors as large as 5 m/s. This study demonstrates that the use of appropriate propagation tools along with the NRL-G2S specifications provides accurate enough results for most of the long-range observations for the purpose of operational infrasound monitoring. Copyright 2007 by the American Geophysical Union.