[ARCHIVE] North West Shelf Significant Wave Height extreme from Observations Reprocessing

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'''DEFINITION''' The CMEMS NORTHWESTSHELF_OMI_SEASTATE_extreme_var_swh_mean_and_anomaly_obs OMI indicator is based on the computation of the 99th and the 1st percentiles from in situ data (observations). It is computed for the variable significant wave height (swh) measured by in situ buoys. The use of percentiles instead of annual maximum and minimum values, makes this extremes study less affected by individual data measurement errors. The percentiles are temporally averaged, and the spatial evolution is displayed, jointly with the anomaly in the target year. This study of extreme variability was first applied to sea level variable (Pérez Gómez et al 2016) and then extended to other essential variables, sea surface temperature and significant wave height (Pérez Gómez et al 2018).

'''CONTEXT''' Projections on Climate Change foresee a future with a greater frequency of extreme sea states (Stott, 2016; Mitchell, 2006). The damages caused by severe wave storms can be considerable not only in infrastructure and buildings but also in the natural habitat, crops and ecosystems affected by erosion and flooding aggravated by the extreme wave heights. In addition, wave storms strongly hamper the maritime activities, especially in harbours. These extreme phenomena drive complex hydrodynamic processes, whose understanding is paramount for proper infrastructure management, design and maintenance (Goda, 2010).

'''CMEMS KEY FINDINGS''' The mean 99th percentiles showed in the area present a wide range from 2.5-4 meters in the English Channel with 0.3-0.4m of standard deviation (std), 4 meters around the Skagerrak Strait with 0.3-0.5m of std to 8-9 meters in the North West of the British Isles with 0.5-0.75m of std. Results for this year show a general trend of negative anomalies within the range of the std, reaching the lowest value (-0.74m) in the North West of the British Isles.

""Note: The key findings will be updated annually in November, in line with OMI evolutions.

'''DOI (product):''' https://doi.org/10.48670/moi-00270