jetströmmar

Jetströmmar are fast-flowing, narrow air currents found in Earth's atmosphere. They are located in the upper troposphere and lower stratosphere, at altitudes where airplanes typically fly. Jetströmmar form at the boundaries between large air masses of different temperatures, such as between polar and tropical air. The greater the temperature difference, the stronger the jet stream. Their movement is driven by a combination of the Coriolis effect, which deflects winds due to the Earth's rotation, and the pressure gradient force, which pushes air from areas of high pressure to areas of low pressure.

There are several major jet streams, with the polar jet stream and the subtropical jet stream being the most significant. The polar jet stream generally flows from west to east at high latitudes, while the subtropical jet stream is found closer to the equator. These jet streams are not static; they meander and shift their positions seasonally and even daily. Their path plays a crucial role in determining weather patterns across the globe, influencing the movement of storms, temperature distributions, and precipitation. Changes in the strength and position of jet streams can lead to extreme weather events, such as prolonged heatwaves, droughts, or heavy rainfall.