Changes in extreme wind speeds over the global ocean

Rianne Giesen and Ad Stoffelen

In 2020, the northern Atlantic experienced both a record-high number of intense tropical cyclones and several heavy storms at higher latitudes. On the other hand, tropical cyclone activity was reduced in the western Northern Pacific. To put these anomalies into a longer-term perspective, we use remotely sensed winds from a scatterometer over the period 2007–2020 to analyse extreme wind speeds over the global ocean, based on the 99th percentile. We compare the 2020 extreme winds to the 2007–2014 climatology and determine significant trends in extreme wind speeds. We find that the 2020 anomalies in the northern Atlantic and Pacific exceed the interannual variability observed over the period 2007–2019, but cannot be directly associated with a significant trend over 2007–2020. On the other hand, large positive extreme wind speed anomalies are found in the southern Indian Ocean, that are in line with steadily increasing extreme wind speeds in this region. Another large positive 2020 anomaly and 2007–2020 trend is observed in the tropical southern Pacific, east of the Solomon Islands. Predominantly negative 2020 anomalies and trends are detected in the southern Pacific Ocean and northwest of New Zealand. Compared to the extreme scatterometer winds, collocated reanalysis model winds are systematically lower and generally exhibit smaller trends.

Bibliographic data

Rianne Giesen and Ad Stoffelen. Changes in extreme wind speeds over the global ocean
Journal: Journal of Operational Oceanography (Copernicus Marine Service Ocean State Report, Issue 6), Volume: 15:sup1, Year: 2022, First page: 8, Last page: 15, doi: 10.1080/1755876X.2022.2095169