Extreme ocean waves can have devastating impacts on many populous coastal regions or offshore islands. Yet, knowledge of how ocean waves are likely to respond to future climate change remains limited. To assess potential increases in risk associated with extreme ocean waves, future changes in seasonal mean and extreme significant wave height (SWH) are examined over the Indian Ocean (IO) using 18 Coupled Model Intercomparison Project Phase 5 (CMIP5) models forced with representative concentration pathway (RCP) 4.5 and 8.5 scenarios. The seasonal maxima are fit to the generalized extreme value (GEV) distribution and corresponding 10-year return values are estimated for the present-day (1981–2010) and future periods (2070–2099). Overall, projected changes in IO SWH exhibit noticeable seasonality. Under the high emissions RCP8.5 scenarios, mean and extreme SWH in the Arabian Sea (AS) and Bay of Bengal (BOB) are projected to increase during all seasons except December–February (DJF). In the western tropical IO (TIO), mean and extreme SWHs are projected to increase during June–August (JJA) and September–November (SON) in line with the projected circulation changes toward an Indian Ocean Dipole (IOD) positive phase-like mean state. Southern IO (SIO) SWHs exhibit a strong zonal shift, with large increases over high-latitudes and decreases over mid-latitudes, which is related to future changes in the Southern Annular Mode (SAM) toward its positive phase. Interestingly, some regions like the western TIO show significantly less increases in SWH under the lower emissions RCP4.5 scenarios, highlighting avoidable future risk through global warming mitigation efforts.

极端的海浪会对许多人口众多的沿海地区或近海岛屿造成破坏性影响。但是，关于海浪可能如何应对未来气候变化的知识仍然有限。为了评估与极端海浪有关的潜在风险增加，使用具有代表性浓度的18种耦合模型比较项目第5阶段（CMIP5）模型检查了印度洋（IO）的季节性平均值和极端显着波高（SWH）的未来变化路径（RCP）4.5和8.5方案。季节性最大值符合广义极值（GEV）的分布，并且估计了当前（1981–2010）和未来时期（2070–2099）的相应10年回报值。总体而言，IO SWH的预计变化表现出明显的季节性。在RCP8.5高排放情景下，预计除12月至2月（DJF）以外的所有季节，阿拉伯海（AS）和孟加拉湾（BOB）的平均和极端SWH都会增加。在西部热带IO（TIO），预计6月至8月（JJA）和9月至11月（SON）的平均和极端SWH会增加，这与预计的印度洋偶极子（IOD）正相类似的环流变化相符。平均状态。南部IO（SIO）SWH表现出强烈的纬向偏移，在高纬度地区有较大的增加，而在中纬度地区则有所减少，这与南环形模式（SAM）朝正阶段的未来变化有关。有趣的是，在较低的RCP4.5情景下，像西部TIO这样的一些地区，SWH的增长显着减少，这凸显了通过缓解全球变暖努力可避免的未来风险。