- #1
physicsponderer
- 74
- 10
Hurricanes tend not to move towards the Equator for very long, turning north fairly soon, and have never been known to reach it, I think. Likewise cyclones in the southern hemisphere, which turn south before reaching it. Why is this? I have two tentative explanations.
1. Hurricanes start out moving west, or south west, carried by the Trades (Trade Winds) and the Coriolis Effect makes them veer right, which is north.
2. The air being sucked in from the south hits the hurricane more directly than the air being sucked in from the north, because the Coriolis effect is stronger the further from the Equator you get. The air from the north strikes a glancing blow, and adds to the rotation more, but pushes the hurricane less, in other words it contributes more to the angular momentum and less to the (linear) momentum of the hurricane, compared to the air coming from the south. Of course, "sucked in" is short for "pushed in by the air at normal atmospheric pressure".
1. Hurricanes start out moving west, or south west, carried by the Trades (Trade Winds) and the Coriolis Effect makes them veer right, which is north.
2. The air being sucked in from the south hits the hurricane more directly than the air being sucked in from the north, because the Coriolis effect is stronger the further from the Equator you get. The air from the north strikes a glancing blow, and adds to the rotation more, but pushes the hurricane less, in other words it contributes more to the angular momentum and less to the (linear) momentum of the hurricane, compared to the air coming from the south. Of course, "sucked in" is short for "pushed in by the air at normal atmospheric pressure".