Manifestations of the Indian Ocean tsunami of 2004 in satellite nadir-viewing radar backscatter variations
Abstract:This paper reports on the first experimental evidence for space-observed manifestations of the open ocean tsunami in the microwave radar backscatter (in the C and Ku bands; electromagnetic wavelengths of 6 and 2 cm, respectively). Significant (a few dB) variations of the radar cross section synchronous with the sea level anomaly were found in the geophysical data record of the altimetry satellite Jason-1 for the track that crossed the head wave of the catastrophic tsunami of 26 December 2004. The simultaneous analysis of the available complementary data provided by the satellite three-channel radiometer enabled us to exclude meteorological factors as possible causes of the observed signal modulation. A possible physical mechanism of modulation of short wind waves due to transformation of the thin boundary layer in the air by a tsunami wave is discussed. The results open new possibilities of monitoring tsunamis from space, for example by support to warning systems based on fixed moorings and coastal stations.
Document Type: Research Article
Affiliations: Institute of Applied Physics Russian Academy of Sciences, Nizhny Novgorod, Russia
Publication date: November 1, 2008