How does the Coriolis Effect help cause spiralling of winds associated with hurricanes?
The Earth is spinning eastwards under the moving air. So that, seen from the ground at points north of the Equator, winds from further north appear to come from the north-east, rather than straight down from the north. This spin also affects the apparent direction of wind from the South Pole and winds moving north and south from the Equator. The explanation is that a point on the ground near the poles rotates at a slower speed than a point nearer the Equator: it travels a smaller circle in the same time. So, for an air mass moving at constant speed from pole to Equator, we find a gradual change in the difference between ground speed and the speed of the air mass. The result is that the air moves in a curve relative to the ground. Blocks of air moving away from the Equator spin relative to the Earth’s surface – clockwise in the northern hemisphere, anticlockwise in the southern. These blocks of warm air collect water vapour from the oceans, creating the familiar ‘lows’ or depressions th
