Natural Variability and Warming Signals in Global Ocean Wave Climates.

This paper presents a multivariate classification of the global wave climate into types driven by atmospheric circulation patterns. The primary source of the net long-term variability is evaluated based on historical wave simulations. Results show that the monsoon, extratropical, subtropical, and polar wave climate types of the Pacific and North Atlantic Oceans are dominated by natural variability, whereas the extratropical and subtropical wave climate types in the Indian Ocean, and the tropical wave climate types of the Atlantic and Pacific Oceans exhibit a global warming signal. In the Pacific sector of the Southern Ocean, strong natural variability may mask a global warming signal that is yet to emerge as being statistically significant. In addition, wave climate teleconnections were found across the world that can provide a framework for joint strategies to achieve the goals of climate adaption for resilient coastal communities and environments. Plain Language Summary Near-surface wind systems drive global ocean wave conditions that are usually studied at regional or local scale. However, analyzing these relationships at the global scale is important to understand how natural climate oscillations, such as El Niño-Southern Oscillation, and global warming, impact wave climate. Here we identify the large wave climates in homology to the climate regions (e.g., Tropical, Temperate, Polar) and are originated by the planetary wind systems. The results show that global warming signals have already emerged in the Indian Ocean and the tropical regions of the Pacific and Atlantic basins. In contrast, in the other ocean basins, natural variability is still the dominant signal and could mask global warming signals. [ABSTRACT FROM AUTHOR]