On this day in 1781, General George Washington, commanding a force of 17,000 French and Continental troops, begins the siege known as the Battle of Yorktown against British General Lord Charles Cornwallis and a contingent of 9,000 British troops at Yorktown, Virginia, in the most important battle of the Revolutionary War.
Earth's rotation causes the trade winds, in a way. If Earth didn't rotate, the wind at these latitudes would blow straight from the subtropical highs to the ITCZ.n the Northern Hemisphere, the Earth rotates counterclockwise so the wind is deflected to the right. The Southern Hemisphere rotates clockwise deflecting the wind to the left. Regardless, the Coriolis effect only influences the direction of the wind, not its speed.
Because the Earth rotates on its axis, circulating air is deflected toward the right in the Northern Hemisphere and toward the left in the Southern Hemisphere. This deflection is called the Coriolis effect. Click the image for a larger view. Coastal currents are affected by local winds. Surface ocean currents, which occur on the open ocean, are driven by a complex global wind system.