Science News

What is Meteorology? The study of atmospheric phenomena Greek root word meteoros.. High in the air

Examples of meteors…

Anything high in the sky Raindrops Raindrops Rainbows Rainbows Dust Dust Snowflakes Snowflakes Fog Fog Lighting Lighting

Atmosphere phenomena are classified as types of meteors Hydrometeors: cloud droplets & precipitation (rain, snow & sleet) Hydrometeors: cloud droplets & precipitation (rain, snow & sleet) Lithometeors: suspended particles (smoke, dust & haze) Lithometeors: suspended particles (smoke, dust & haze) Electrometers: signs of electricity (thunder & lighting) Electrometers: signs of electricity (thunder & lighting)

Variations of Atmosphere Phenomena Weather: short term variations in atmospheric phenomena Weather: short term variations in atmospheric phenomena Climate: long term average of variations in weather for a particular area (over 30 years) Climate: long term average of variations in weather for a particular area (over 30 years)

4 causes of weather 1. The uneven solar heating of the earth’s surface 2. Transfer of thermal energy (R,C,C) 3. Water phase change (E,C,P) releasing latent heat 4. Air masses traveling & colliding

Air Masses Air Mass: a large body of air that has the same characteristics (Temperature & Moisture) as its source region Air Mass: a large body of air that has the same characteristics (Temperature & Moisture) as its source region Source Region: area of earth’s surface that effects air mass formation Air Mass Modification: As it moves over land or water with different characteristics, it transfers thermal energy and/or moisture

Air Mass Classification Moisture: influenced by surface Moisture: influenced by surface designated m for maritime (wet) & c for continental (dry) c for continental (dry) Temperature: influenced by latitude Temperature: influenced by latitude High Latitude = Cold & Low Latitude = Warm A (arctic), P (polar) and T (tropical)

Mid latitudes are zones of clashing air masses = stormy

Air Masses Effecting North America Much of the weather in North America, especially weather east of the Rocky Mountains, is influenced by Much of the weather in North America, especially weather east of the Rocky Mountains, is influenced by continental polar (cP) & maritime tropical (mT) air masses.

HOMEWORK Review Notes Quiz Tomorrow Review Notes Quiz Tomorrow Read Text p 312 – 316 Read Text p 312 – 316 Ch 12 Study Guide Sheet due Friday 4/3 Ch 12 Study Guide Sheet due Friday 4/3

QUIZ 1. Define Weather 2. Define Climate 3. Name one cause of weather 4. Name the two classifications of air masses 5. (m) Maritime air mass has what characteristic? BONUS What degree latitude is the Tropic of Cancer?

Science News Day & Night Across the Earth Sun and Moon Data for CHICAGO IL Sun and Moon Data for CHICAGO IL

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AIR MASSES & WEATHER Continental polar (cP) From northern Canada and interior of Alaska Winter very cold, dry Winter very cold, dry Summer cool, dry Summer cool, dry Responsible for lake-effect snows Responsible for lake-effect snows Mass crosses the Great Lakes Mass crosses the Great Lakes

AIR MASSES & WEATHER Maritime polar (mP) From North (P)acific & (A)tlantic Oceans Winter (P) mild, humid (A) cold, humid Winter (P) mild, humid (A) cold, humid Summer (P) mild, humid (A) cold, humid Summer (P) mild, humid (A) cold, humid Influence in the northeastern & western United States causing cold temperatures and snow Influence in the northeastern & western United States causing cold temperatures and snow

AIR MASSES & WEATHER Continental tropical (cT) From Southwest and Mexico Winter warm, dry Winter warm, dry Summer hot, dry Summer hot, dry

AIR MASSES & WEATHER Maritime tropical (mT) From the Gulf of Mexico and the Atlantic Ocean Winter warm, humidWinter warm, humid Summer hot, humidSummer hot, humid Eastern USA Usually unstable!Eastern USA Usually unstable!

What is WIND? The horizontal motion of air across Earth’s surface; movement produced by differences in air pressure from an area of high pressure (warm air) to an area of low pressure (cool air)

GLOBAL WINDS

Global Winds The atmosphere balances differences of unequal heating by acting as a giant heat- transfer system. This system moves warm air toward high latitudes and cool air toward the equator

GLOBAL Direction of WIND

3 WIND SYSTEMS “ZONES” Polar easterlies 60 DEGREES – POLES N & S LATITUDES 60 DEGREES – POLES N & S LATITUDES Dense cold air sinking from the polar high toward the sub polar low. These winds are not constant like the trade winds. Dense cold air sinking from the polar high toward the sub polar low. These winds are not constant like the trade winds.

Westerlies 30 – 60 DEGREES N & S LATITUDES 30 – 60 DEGREES N & S LATITUDES Dominant and steady surface wind moving west-to-east towards the POLES. Move much of the weather across USA & Canada. Dominant and steady surface wind moving west-to-east towards the POLES. Move much of the weather across USA & Canada.

Trade winds  30 degrees N – 30 degrees S LATITUDES  Two belts of winds, air in this region sinks, warms and moves toward the equator in an easterly direction.

Boundaries of Wind Systems JET STREAM: A narrow band of fast moving wind that varies with seasons Result of the difference between air masses (Temperature & Pressure) at the wind zone boundaries. Result of the difference between air masses (Temperature & Pressure) at the wind zone boundaries.

2 Types of JETSTREAMS Major POLAR JET STREAM Separate polar easterlies from prevailing westerlies Separate polar easterlies from prevailing westerlies Move East to West Move East to West Latitudes 40 N- 60 N & Latitudes 40 N- 60 N & 40 S-60 S

MinorSubtropical Separate trade winds from westerlies Separate trade winds from westerlies Latitudes 20 N – 30 N & Latitudes 20 N – 30 N & 20 S – 30 S

Why are the winds systems broken into zones?? Coriolis effect

HOMEWORK Review Notes Quiz Tomorrow Review Notes Quiz Tomorrow Read Text p Read Text p Ch 12 Study Guide Sheet due Friday 4/3 Ch 12 Study Guide Sheet due Friday 4/3