Unit 4 Lesson 5 Weather and Climate S8.D.2.1.1-3

Weather vs Climate Weather Climate Is the condition of the atmosphere including temperature, pressure, and humidity at a particular time and place Climate Is the average weather of an area over a long period of time Warmer climates exist near equator and colder climates exist near poles

Earths Atmosphere Temperature changes and the atmosphere

Air Masses A large body of air that has the same temperature and humidity throughout  the amt of water vapor in the air air masses take on the characteristics of the area over which they form over sea (maritime) wet over land (cont.)  dry they move in certain directions

Air Pressure Also called Barometric Pressure Is the weight of the air pushing down on a particular area Pressure system  region of atmosphere that has a similar barometric pressure throughout  Two types High Pressure System Low Pressure System

High Pressure System Generally produces clear, dry skies Predicting Weather If the barometric pressure is rising, a high pressure system is moving in and weather will clear up

Low Pressure System Often brings rain or snow Predicting Weather If the barometric pressure is dropping, a low pressure system is moving in and weather will become cloudy and rainy/stormy

Clouds When air rises it cools and the water vapor in the air condensed into tiny liquid droplets which make up a cloud Nimbus producing precipitation

Stratus clouds Cumulus Clouds Cirrus Clouds associated with overcast days Cumulus Clouds puffy white clouds on fair days Can turn into storm clouds Cirrus Clouds high, feather-like clouds associated with clear sunny days

Clouds

Prevailing Winds Winds close to the earth’s surface that consistently blow in the same direction Can affect an area’s climate

Effect of Water on Weather Large bodies of water (oceans) can store large amounts of heat During Cold Months: If water is warmer than air, heat will move to air, bringing warmer weather to cold areas During Hot Months: If air is warmer than cool water, heat will move to the water, bringing cooler weather to warm areas

Effect of Water on Weather Because water warms and cools so slowly relative to land and air, areas near large bodies of water tend to have more stable temperatures Places located near large bodies of water have warmer winters and cooler summers. Myrtle Beach will have warmer winters and cooler summers than Columbia

Lake-Effect Snow Cold arctic air blows over warmer Great lakes Air close to lake becomes warm and moist and rises As it rises, water vapor condenses into clouds As clouds move over opposite shore, they release snow

Lake-Effect Snow