article_snippet: strong winds have a mostly constant speed at different latitude, but nearer the pole they circle the planet quicker as the circumference of the planet is smaller.
article_snippet: But we must consider that these waves propagate over a "sphere", and "circles" completed both at the equator and at 40ºN have a different radius (the higher latitude, the smaller the parallels or circles are). '
article_snippet: So, having the same velocity than that at the equator, anything moving horizontally at 40º will complete the longitude of the circle sooner
article_snippet: that when doing the same at the equator. '
article_snippet: The area of the wave at higher latitudes complete circles quicker than at the equator.'
article_snippet: The effect is also amplified by the winds moving round the planet nearer the poles (Marine 10 image from 1974 shown left).