2. Tsunami-driven Traveling Ionospheric Disturbances (TIDs) From Artru et al., 2005

3. Motivation: Why add ionospheric observations? DART buoy system is expensive: – ~$250,000 per buoy to build – DART system cost $12 M to maintain/operate in 2009 (28% of NOAA’s total tsunami-related budget)* Buoys are sparsely distributed, temperamental – Data available 84% of time, outages due to harsh weather, human error* GPS Receivers are more abundant, multi-use, low-cost Additional means of observing tsunamis over a broader area could help to validate and improve theoretical model predictions, contributing to tsunami early warning system. *Government Accountability Office (GAO) report, April 2010 http://www.gao.gov/cgi-bin/getrpt?GAO-10-490

4. Regional Networks Source: Scripps Orbit and Permanent Array Center (SOPAC) GPS Data Archive, UCSD http://sopac.ucsd.edu/cgi-bin/somi4i 4 Source: Japanese GPS Earth Observation Network (GEONET) Array Over 1200 stations http://terras.gsi.go.jp/gps/geonet_top.html GEONET Array

5. Streaming 1-second data availability Currently up to 130 stations worldwide providing 1-second realtime data. http://www.gdgps.net/http://www.gdgps.net/, ftp://cddis.gsfc.nasa.gov/pub/gps/data/highrate

6. American Samoa Tsunami 9/29/09 Observed near Hawaii (zoomed in) NOAA MOST tsunami model (background) Variations in ionospheric total electron content (colored dots)

7. American Samoa Tsunami 9/29/09 Observed at Hawaii (zoomed out) Galvan et al., 2011 (submitted) NOAA MOST tsunami model (background) Variations in ionospheric total electron content (colored dots)

8. Chile Tsunami 2/27/10 Observed at Japan NOAA MOST tsunami model (background) Variations in ionospheric total electron content (colored dots)

9. Summary Tsunami-driven TID’s observed via GPS TEC after the American Samoa Tsunami of 9/29/2009 and the Chilean tsunami of 2/27/2010. (Galvan et al., submitted) Models predict tsunami-driven TID’s. (Occhipinti et al., 2008; Hickey et al., 2009; Mai and Kiang, 2009). Observations: Typically ~0.1 – 0.5 TECU. 30-second archived data AND 1-second real-time data available for study, both ground-based and LEO (COSMIC). Long-term potential for warning system.