Seasonality of wind speeds and wave heights from 30 years of satellite altimetry

The annual cycle and associated harmonics contain the majority global wind and wave field variance. Yet, these annual variations are not studied in detail. Here we develop a non-parametric method to classify the seasons using observations from a multi-platform calibrated altimeter dataset from 1985 to 2016. Our approach makes no assumptions of the seasonal features and handles a wide range of behavior. After classification, we document seasonal averages, standard deviations, slopes, phases, and lengths that reveal a unique view of the wind speed and wave height global seasonal patterns. We find some regions of the ocean have distinct seasonal shapes different from sinusoids. Lastly, we identify several regions of the ocean that have strong seasonal inter-annual variability while other regions have small year-to-year variability which might be important areas to monitor for long-term changes related to variability in solar radiation or climate change.