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Secondary Gravity Waves From the Tonga Volcano Eruption: Observation and Modeling Over New Zealand and Australia

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Author(s):
Figueiredo, C. A. O. B. ; Vadas, S. L. ; Becker, E. ; Wrasse, C. M. ; Takahashi, H. ; Nyassor, P. K. ; Barros, D.
Total Authors: 7
Document type: Journal article
Source: JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS; v. 128, n. 10, p. 13-pg., 2023-10-01.
Abstract

The biggest volcanic eruption since 1991 happened on 15 January 2022 on the island of Hunga Tonga-Hunga Ha'apai (20.6 degrees S; 175.4 degrees W) in the South Pacific between 4:00 and 4:16 UT. The updrafts from the eruption reached 58 km height. In order to observe its ionospheric effects, approximately 750 GNSS receivers in New Zealand and Australia were used to calculate the detrended total electron content (dTEC). Traveling ionospheric disturbances (TIDs) were observed over New Zealand 1.0-1.5 hr after the volcano eruption, with a horizontal wavelength (lambda(H)) of 1,525 km, horizontal phase velocity (C-H) of 635 m/s, period (tau) of 40 min, and azimuth (alpha) of 214 degrees. On the other hand, TIDs were observed 2-3 hr after the eruption in Australia with lambda(H), C-H, tau, and alpha of 922 km, 375 m/s, 41 min, and 266 degrees, respectively. Using reverse ray tracing, we found that these GWs originated at z > 100 km at a location similar to 500 km south of Tonga, in agreement with model results for the location of a large amplitude body force created from the breaking of primary GWs from the eruption. Thus, we found that these fast GWs were secondary, not primary GWs from the Tonga eruption. (AU)

FAPESP's process: 18/09066-8 - TRAVELLING IONOSPHERIC DISTURBANCES OBSERVED BY DETRENDED TOTAL ELECTRON CONTENT MAPS/KEOGRAM OVER ANDES MOUNTAINS
Grantee:Cosme Alexandre Oliveira Barros Figueiredo
Support Opportunities: Scholarships in Brazil - Post-Doctoral
FAPESP's process: 19/22548-4 - Sources of traveling ionospheric disturbances over the Andes mountains
Grantee:Cosme Alexandre Oliveira Barros Figueiredo
Support Opportunities: Scholarships abroad - Research Internship - Post-doctor