Statistical Assessment of Extreme Storm Events on the Brazilian Continental Shelf from 1940 to 2022

Alfredini, P.; Martins, L.F.; Neves, R.C.; Martinez, F.A., and Arasaki, E., 2024. Statistical assessment of extreme storm events on the Brazilian Continental Shelf from 1940 to 2022. In: Phillips, M.R.; Al-Naemi, S., and Duarte, C.M. (eds.), Coastlines under Global Change: Proceedings from the International Coastal Symposium (ICS) 2024 (Doha, Qatar). Journal of Coastal Research, Special Issue No. 113, pp. 175-179. Charlotte (North Carolina), ISSN 0749-0208. The Brazilian Continental Shelf is the largest in Latin America and the South Atlantic Ocean, covering more than 8,500 km and stretching from Latitude S 34° to Latitude N 6°. The Rio de La Plata Delta discharges sediment over a wide area in the southern portion of this shelf. Submerged peaks of the Vitória-Trindade Chain have an influence on an intermediate region of the shelf. Northward, the Continental Shelf becomes thinner, until reaching its maximum width in the Maranhão Gulf and Amazon Mouth. In addition to the different wave climates along the Brazilian coast, around 55% of the country's population lives in the coastal region, with large population concentrations in metropolitan regions, such as Rio de Janeiro, Salvador, Recife and Fortaleza. The oil and gas industry has many offshore structures on the Continental Shelf, and the cargo throughput from ports reached 1.217 billion tons in 2023. Therefore, any change in meteo-oceanographic patterns in Brazilian Continental Shelf can have major impacts because maritime infrastructures and operations tend to be progressively affected by the increasing frequency and intensity of extreme meteorological phenomena due to climate change. Impacts like coastal erosion, augmented occurrence of storms and flooding can damage essential infrastructure in cities, ports, and other coastal and offshore scenarios. Therefore, understanding these changes is necessary for planning and executing actions to mitigate and adapt. The objective of this paper is to make a statistical assessment of a first approach to identify trends that may point changes in the extreme events of storm over the period from 1940 to 2022, assessing time series of wave data from the European Centre for Medium-Range Weather Forecasts ERA 5 Oceanographic Model, in twelve locations of Brazilian Continental Shelf, from the extreme south to the extreme north. The storm events were identified by the peak over threshold method and the statistical assessment employed moving averages for 5 years and was possible to identify an increasing frequency and severity of storm per year from 1980 in the south and a smaller increase in the northern area.