Local Winds, Global Winds and The Jet Streams How do Local winds differ from global winds? How do global winds and the jet stream influence weather and climatic conditions?

Generally move short distances and can blow in any direction Local Winds Generally move short distances and can blow in any direction Caused by geographic features that produce temperature differences. Ex: Mountain breezes and valley breezes.

Global Winds Global winds Effect the entire planet. Are found in each convection region where warm air rises towards the poles. These uneven heating zones produces pressure belts which occur every 30° latitude on the Earth. Tropical 0°-30° North or South of the equator. Temperate Horse latitudes 30°-60° North or South of the equator. Polar 60°-90° North or South of the equator (to the North or South Poles).

Doldrums Located along the equator where no winds blow because the warm rising air creates and area of low pressure

E W Trade Winds Blow from East to West. From 30 degrees almost to the equator in both hemispheres. Called this by use of early traders/explorers. Tropical Region; moving warm tropical air in that climate zone. W E

Prevailing Westerly Winds Blow from west to east in the Flow towards the poles from west to east carrying moist air over places in this area. From 30 degrees to 60 degrees Temperate Region. W E

Global Winds The Temperate Zone temperatures are affected most by the changing seasons, but since the Westerly Wind Belt is in that region, the weather systems during any season move from west to east. E W

Global Winds Since the United States is in the Westerly Wind Belt, the weather systems move across the country from West to East. W E

NE W Polar Easterlies Blow Northeast to West in the Polar Region From the 0 to 60 degrees. Moving cold polar air in that from the poles toward the West. In both hemispheres. NE W

Global Winds Polar Winds Westerly Wind Belt Trade Winds The Polar Winds are in the Polar Region moving from NE to W The Westerly Wind Belt is in the Temperate Region moving from W to E. The Trade Winds are in the Tropical Region moving from E to W. Polar Winds Westerly Wind Belt Trade Winds

Jet Stream A narrow belt of strong winds that blow in the upper troposphere/lower stratosphere A fast, strong flowing, river of air Usually flow from west to east Can rise, dip or split bringing in cold or warm air to the US. Meteorologist and pilots study this. Effects storm movement Jet Stream (click for video)

Jet Stream As these changes occur, air masses and weather systems in its path are moved along by the fast moving air. E W

Jet Stream The cold Polar Jet Stream can bring down cold, polar conditions from the North. N

Jet Stream The Subtropical Jet Stream can bring warm tropical conditions from the South (in the Northern hemisphere). N S