Future changes in Gulf of Mexico hurricane wave climatology

Meeting industry demand for assessments of future changes in Gulf of Mexico hurricane impacts is a challenge that extends well beyond simply improving climate prediction. Once the climate predictions have been made, there remains a huge gap regarding how this affects industry. The National Center for Atmospheric Research is actively engaged in a collaborative project with the Research Partnership to Secure Energy for America, Chevron Energy Technology Company and Willis Re to align the latest climate research with the requirements of industry. This paper explores methods to simulate and predict future changes in hurricane impacts on the offshore energy industry. We first expand the concept of the Saffir-Simpson hurricane categorical scale to include important characteristics of the wind field for damage including maximum wind speed, storm translation speed and size, in a new Cyclone Damage Potential index. The index is applied to simulated current and future hurricanes to assess future changes in hurricane damage potential. Loading on structures in the Gulf of Mexico is a complex function of not only characteristics of the wind field but also ocean characteristics including currents and waves. Simple empirical relationships between wind, wave and current miss some of the essential physics, particularly for extreme events. To improve upon the damage potential assessments we need to account for the full physical interactions between wind, wave and current. This paper explores the ability of fully coupled atmosphere-ocean dynamical simulations to capture metocean hurricane conditions through a case study simulation of Hurricane Katrina. This preliminary case study simulation establishes the simulation technology that will then be used to build robust assessments of the 100-year load and its future change using a combined theoretical and dynamical-statistical approach.