Projected impact of climate change on waves at Mumbai High

Structures built in the sea are traditionally designed according to historical climate observations or hindcasts. In geographical locations typical of India, such designs do not take the effect of future climate change into account. For structural safety, considerations of such effects are highly desirable. Many recent studies have demonstrated likely changes in the extreme wave conditions at different offshore locations. This paper reports similar results in the Mumbai High region, where the majority of India's offshore oil platforms are located. Using historical wind data provided by the National Centre for Environmental Prediction/National Centre for Atmospheric Research and a Canadian general circulation model for future data (CMIP5-RCP8.5), a numerical wave model of the past and future wave conditions was simulated over a 40-year period. A statistical analysis of both past and projected datasets obtained significant wave heights with a 100-year return. The comparison of wave heights derived from past and future datasets showed that wave magnitudes would increase at almost all locations within the Mumbai High area. The northern locations may undergo a significant rise from 10% to 28%, while the southern sites may experience a smaller increase, from almost zero to 10%, under the highest projected pathway of global warming.