CLIMATE CHANGE PERSPECTIVES OF THE CYCLONES AND OCEANIC HAZARDS IN THE WESTERN SOUTH ATLANTIC OCEAN

Perspectivas das mudanças climáticas dos ciclones e riscos oceânicos no oeste do Oceano Atlântico Sul

Abstract

Cyclone-related oceanic hazards, such as extreme waves and surges, are frequently reported on the western South Atlantic. These events are associated with coastal erosion, coastal infrastructure damage, maritime navigation, and offshore industry incidents, being important for safety and maintenance management in ocean engineering. Present climate trends and future projections of this event are frequently linked with the expected general poleward shift of the storm track over the globe, but regional approaches revealed a slight increase in the cyclonic activity in South America 35ºS and 40ºS, which would be restricted to the coast. However, the signals of these changes are weak and frequently of the same magnitude of model biases, producing results with a lack of confidence, especially in the coastal zone. Extreme events related to waves and surges used to present large uncertainty and heterogeneity around the globe. Most of the problems regarding future estimation rely on methodological limitations that will not overrun without collaborative efforts to the improvement of observational-based science. Taking advantage of the UN Ocean Decade goals, national and regional initiatives need to collaborate towards a robust and continuous Brazilian observational network in order to face the climate crises in the country.

Keywords: ocean wind-waves, coastal flooding, storm surge, extratropical cyclones, ocean waves, natural hazards.