Winds Wind is caused by differences in air pressure. The greater the difference the greater the wind speed. Close Isobars= High Winds Widely Spaced Isobars= Low Winds

The Coriolis Effect The rotation of Earth causes a curving path of winds and ocean currents. Northern Hemi – right Southern Hemi – left https://www.youtube.com/watch?v=mPsLanVS1Q8 https://www.youtube.com/watch?v=i2mec3vgeaI

Global Winds Winds caused by uneven heating of Earth’s atmosphere. Equator gets more sunlight… This air expands, rises and flows toward poles Polar air is denser so it flows toward the equator Non-rotating Earth, 2 cells(North & South) ->

Because of Earth’s rotation, instead of 2 cells we have 6 Global Winds Because of Earth’s rotation, instead of 2 cells we have 6 Winds are named by the direction from which they blow.

Global Winds Trade Winds: occurs at 30* north and south latitude Around 30* latitude, air sinks causing high pressure = weaker winds Near equator, air rises causing low pressure = stronger winds

Global Winds Prevailing Westerlies: flows between 30* and 60* north and south latitude in a circulation pattern opposite that of the trade winds Wind blows from the west to the east Responsible for movement of weather across US

Global Winds Polar Easterlies: lies between 60* latitude and the poles Cold air mass that blows toward the east

The Jet Stream: narrow bands of fast, high- altitude, westerly winds Polar Jet stream = separates polar easterlies and prevailing westerlies Subtropical jet stream = separates the trade winds and prevailing westerlies

Notes. The more the better! Front Symbol Air Mass Diagram  Weather Notes. The more the better!  

Types of Fronts – Cold Front Cold fronts form when cold air moves under warm air and pushes the warm air up. Cold fronts can bring thunderstorms, heavy rain, snow, and cooler temperatures Cold fronts can move up to twice as fast as warm fronts

Types of Fronts – Warm Front Warm fronts form where warm air moves over cold air The warm air gradually replaces the cold air Brings clouds and drizzly rain

Types of Fronts – Stationary Front Stationary fronts form when both air masses have similar densities Can bring rain and cloudy weather that lasts for days

Types of Fronts – Occluded Front Occluded fronts form when a fast moving cold front catches up to a warm front Brings cool temperatures and large amounts of rain and snow

Pressure Systems

Counter-Clockwise spin High and Low Pressure Areas of Low pressure are characterized by: Hot Air Rising This leads to clouds and precipitation Low Pressure = Cyclone Counter-Clockwise spin

High and Low Pressure Areas of High pressure are characterized by: Cold Air Sinking winds blowing away in clockwise motion High Pressure = Anti-cyclone