Long-Term and Seasonal Trends in Global Wave Height Extremes Derived from ERA-5 Reanalysis Data

• Published in: Journal of Marine Science and Engineering
• Main Authors: Alicia Takbash, Ian R. Young
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2020
• Subjects: extreme wave height; extreme value analysis; wave climate; wave model; reanalysis; Naval architecture. Shipbuilding. Marine engineering; VM1-989; Oceanography; GC1-1581; Southern Ocean
• Online Access: https://doi.org/10.3390/jmse8121015; https://doaj.org/article/ee200b3fcf3343a9abd12b1db0acf863

A non-stationary extreme value analysis of 41 years (1979–2019) of global ERA5 (European Centre for Medium-Range Weather Forecasts Reanalysis) significant wave height data is undertaken to investigate trends in the values of 100-year significant wave height, <math display="inline"><semantics><mrow><msubsup><mi>H</mi><mi>s</mi><mrow><mn>100</mn></mrow></msubsup></mrow></semantics></math> . The analysis shows that there has been a statistically significant increase in the value of <math display="inline"><semantics><mrow><msubsup><mi>H</mi><mi>s</mi><mrow><mn>100</mn></mrow></msubsup></mrow></semantics></math> over large regions of the Southern Hemisphere. There have also been smaller decreases in <math display="inline"><semantics><mrow><msubsup><mi>H</mi><mi>s</mi><mrow><mn>100</mn></mrow></msubsup></mrow></semantics></math> in the Northern Hemisphere, although the related trends are generally not statistically significant. The increases in the Southern Hemisphere are a result of an increase in either the frequency or intensity of winter storms, particularly in the Southern Ocean.