Transcript Air Masses
Starter Puzzle in the Air The jumble of words below makes no sense. But if you put the words in order, they reveal something about the atmosphere and its relationship to the earth. Write the message- a compound sentencein your notebook. in changed earth’s has changes atmosphere life affect conditions Life and the for atmosphere Starter Bring on the Weather • Weather is what we call the day-to-day changes in wind, temperature, humidity, and air pressure. • In the puzzle below, empty spaces follow some of the letters in the word WEATHER. Fill in the spaces with weather-related words that start with that letter. W. Wind, water E. A. T. temperature H. humidity E. R. Starter • Prepare for your quiz on weather. Starter Quiz 1. Which layer of the atmosphere do we live in? 2. Which 2 major gases is the atmosphere composed of? 3. Why do planes fly in the stratosphere? 4. Where would a cP air mass originate? 5. What kind of weather is expected with a cold front? Starter Answers 1. 2. 3. 4. 5. Troposphere Nitrogen and Oxygen To avoid bad weather Over continental land at the poles Stormy weather; heavy rains. Clouds Up Above • When air is cooled below its dew point, water vapor becomes liquid water. Condensation occurs, and clouds may appear. A cloud’s shape depends on the air moving around it. Circle the two words next to each basic cloud type that best describe it. 1. Cumulus 2. Stratus 3. Nimbus 4. Cirrus puffy low dry ice icy thin cauliflower billowy feathery layers rain wispy snow windy low drizzle high desert heavy spiky flowery misty Air Masses, Fronts Air Density • The amount of air contained in a specific volume • Factors that affect it: ▫ Temperature-As temperature rises, air density drops ▫ Air Pressure-Air density increases with increased pressure ▫ Altitude-As altitude increases, air pressure decreases & density ▫ Humidity-The more moisture in the air the lower the air density Air Masses • A large body of air that takes on the characteristics of the area over which it forms ▫ ▫ ▫ ▫ ▫ Continental Tropical (cT) Maritime Tropical (mT) Continental Polar (cP) Maritime Polar (mP) Arctic (A) Where they originated: • c- Land • m-Water • T- Equator • P- Poles Air Masses • Air masses move when they encounter a pressure difference with a surrounding air mass ▫ When air masses meet generally severe weather occurs (ex. Hurricanes & tornadoes) Fronts • A front is a narrow region separating two air masses of different densities ▫ ▫ ▫ ▫ Cold Front Warm Front Stationary Front Occluded Front Cold Front • In a cold front cold, dense air displaces warm air and forces the warm air up. As warm air rises it cools and condenses. • Clouds,heavy showers and violent thunderstorms are often associated with cold fronts. Warm Front • In a warm front warm air displaces cold air. • A warm front is characterized by extensive cloudiness and precipitation. Stationary Front • In a stationary front two air masses meet and neither advances • There are rarely any clouds or heavy precipitation Occluded Front • An occluded front occurs when a cold air mass moves so quickly that it overtakes a warm front. • The warm air is wedged upward • The air near the ground becomes cooler. The warm air cools and its moisture condenses forming clouds and rain or snow. Wind Systems • Wind occurs due to a pressure/temperature difference between 2 air masses • There are 3 zones of winds systems in each hemisphere caused by the Coriolis Effect Trade Winds (Located 0-30 N and S). Blows East-West Prevailing Westerlies (Located 30-60 N and S) Blows West-East Polar Easterlies (Located 60-90 N and S) Blows East-West) The Coriolis Effect Homework • On page 28 construct a Venn Diagram Comparing warm and cold fronts!!!!