- Slides: 5
Wind • Definition • Air movement • The movement of air caused by differences in air pressure • Warm air rises at the equator and cool air sinks at the poles • Rising air creates low pressure areas. Sinking air creates a high pressure area. • The movement of air causes large circular patterns of wind called convection cells.
• Naming Winds • Global Winds • Winds are named from the directions they are blowing from • Movement of air within the convection cells • Polar Easterlies – From poles to 60 degrees latitude • Prevailing Westerlies – 60 degrees to 30 degrees latitude • Trade Winds – 30 degrees to 10 degrees latitude • Doldrums – 10 degrees latitude to the equator. Very little wind is here because all the air is warm and rising
• Jet Stream • A narrow belt of strong winds that blow in the upper troposphere • Can reach speeds of 400 km/h • Can affect the movement of weather, fronts, and storms around the world
• Local Winds • Winds that move short distance and can blow from any direction • Geographic features such as shorelines or mountains that produce temperature differences can create local winds
• Sea and Land Breezes • Mountain and Valley Breezes • During the day, land heats up faster so the air above land rises. Air over the ocean flows in to replace it. The process reverses at night. • During the day warm air rises up along the mountain slopes creating valley breezes. At night cool air sinks down the mountain slopes producing a mountain breeze