Estimation of extreme wave height return periods from short-term interpolation of multi-mission satellite data: application to the South Atlantic

We analyzed the spatial pattern of wave extremes in the South Atlantic Ocean by using multiple altimeter platforms spanning the period 1993–2015. Unlike the traditional approach adopted by previous studies, consisting of computing the monthly mean, median or maximum values inside a bin of certain size, we tackled the problem with a different procedure in order to capture more information from short-term events. All satellite tracks occurring during a 2-day temporal window were gathered in the whole area and then gridded data were generated onto a mesh size of inline-formula $M1inlinescrollmathml\mathrm{normal\; 2}{}^{\circ }\times \mathrm{normal\; 2}{}^{\circ }$ 34pt11ptsvg-formulamathimgc7e9739dbc673f515f0ac409479e85e6 os-14-911-2018-ie00001.svg34pt11ptos-14-911-2018-ie00001.png through optimal interpolation. The peaks over threshold (POT) method was applied, along with the generalized Pareto distribution (GPD). The results showed a spatial distribution comparable to previous studies and, additionally, this method allowed for capturing more information on shorter timescales without compromising spatial coverage. A comparison with buoy observations demonstrated that this approach improves the representativeness of short-term events in an extreme events analysis.