Origin of the ahead of tsunami traveling ionospheric disturbances during Sumatra tsunami and offshore forecasting

Author(s)

Bagiya, Mala S. ; Kherani, E. A. ; Sunil, P. S. ; Sunil, A. S. ; Sunda, S. ; Ramesh, D. S.

• Document type: Journal article
• Source: JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS; v. 122, n. 7, p. 7742-7749, JUL 2017.
• Web of Science Citations: 2

Abstract

The presence of ionospheric disturbances associated with Sumatra 2004 tsunami that propagated ahead of tsunami itself has previously been identified. However, their origin remains unresolved till date. Focusing on their origin mechanism, we document these ionospheric disturbances referred as Ahead of tsunami Traveling Ionospheric Disturbances (ATIDs). Using total electron content (TEC) data from GPS Aided GEO Augmented Navigation GPS receivers located near the Indian east coast, we first confirm the ATIDs presence in TEC that appear similar to 90 min ahead of the arrival of tsunami at the Indian east coast. We propose here a simulation study based on tsunami-atmospheric-ionospheric coupling that considers tsunamigenic acoustic gravity waves (AGWs) to excite these disturbances. We explain the ATIDs generation based on the dissipation of transverse mode of the primary AGWs. The simulation corroborates the excitation of ATIDs with characteristics similar to the observations. Therefore, we offer an alternative theoretical tool to monitor the offshore ATIDs where observations are either rare or not available and could be potentially important for the tsunami early warning. (AU)

• FAPESP's process: 11/21903-3 - Traveling ionospheric disturbances: simulation and observation, the importance of latitudinal coupling of gravity wave-Perkins-Es layer instabilities and forcing from pre-seismic events
• Grantee: Esfhan Alam Kherani
• Support Opportunities: Research Grants - Young Investigators Grants