Abstract While the Southern Ocean is known to have the strongest annual‐mean surface winds globally, it remains unclear whether surface wind extremes are stronger there than over the Northern Hemisphere basins. We address this question by analyzing reanalysis and satellite data sets and employing feature tracking to associate cyclones with surface winds. Consistent with previous work, we find the highest annual‐mean and median winds over the Southern Hemisphere. However, we find a statistically distinguishable hemispheric asymmetry in extreme surface windspeeds, with the Northern Hemisphere having stronger extremes. The stronger extremes in the Northern Hemisphere are driven primarily by extreme windspeeds occurring during winter and in proximity to cyclones (within a 1,000 km radius around objectively tracked cyclone centers). Large‐scale differences between basins likely play a role in shaping hemispheric asymmetries, as the Northern Hemisphere has higher extreme windspeeds above the boundary layer (700 hPa) and higher extremes of midtropospheric Eady growth rates.

Read original article