Observing and modelling the high water level from satellite radar altimetry during tropical cyclones

Abstract

This paper investigates the capability of observing tropical cyclones using satellite radar altimetry. Two representative cyclones Yasi (February 2011) and Larry (March 2006) in the northeast Australian coastal area are selected based also on available tide gauge sea level measurements. It is shown that altimetry data can capture high water levels induced by Larry and Yasi through a careful re-processing and re-editing of the data. About 18 years of data from multi-satellite altimetry missions including TOPEX/Poseidon, Jason- 1 and Jason-2, and seven tide gauges around the northern Australian coast are integrated using a multivariate regression approach. The results reveal that the multi-regression model can, in general, explain >60% of sea level variances in the study area. The model is then validated using independent data from tide gauge in Townsville. The comparison results indicate that the high sea levels predicted by the model taken into account of both altimetry and tide-gauge data agree well with those observed at Townsville during cyclone Larry.