The jet stream helps transport the weather to different parts of the earth depending on the location the weather is coming from and the type of weather. Here in the United States we have the polar jet and the tropical jet. The polar jet comes from places near the top of the globe such as the North Pole, and the tropical jet comes from areas at the equator and slightly below. The Coriolis effect is caused by the rotation of the earth on its axis. It has major effects on climate throughout the United States and also affects ocean currents. It also affects how storms rotate, depending on their location and the direction they will spin. In the Northern Hemisphere thunderstorms rotate counterclockwise while in the Southern Hemisphere they rotate clockwise. The weather here in the United States changes seasonally. We have four different seasons here. The different seasons are spring, summer, autumn and winter. These seasons change due to the tilt of the Earth's axis. The way the earth tilts affects the season, so if it tilts further down it will start to get hotter but when it tilts up it will start to get hotter