Editorial: Why the 'roaring forties' do not roar all the time
Climatological maps in atlases represent rainfall, temperature, pressure and wind on a very broad scale. Some older atlases have maps of mean pressure with the words 'Roaring Forties' printed over a concentration of isobars in the Southern Hemisphere. New Zealand lies in this zone. There is no equivalent zone in the Northern Hemisphere and this feature represents one of the most remarkable climatic differences between the Hemispheres.