Review Day  Drill: Complete the sentence. ________ pressure systems are caused by ________ air rising allowing clouds to form.  Objective: SWBAT identify key components of the Weather Factor in order to prepare for the unit test.  HW: Study

Factors Affecting Weather Review  Measuring Air Pressure: Barometer (inches, milibars) Mercury: Liquid mercury rises in the cylinder as air pressure increases. Anaroid: Solid thin metal walls that expand or push in based on atmospheric pressure.  Thermometer: Temperature: Average amount of energy of a substance and measured in Celsius (0 – 100) and Fahrenheit (32 – 212).

Winds: Caused by differences in pressure. Horizontal movement of air.  Measuring: Uses an anemometer; see picture.  Wind chill factor: Removes heat from skin causing it to feel cooler than it actually is.

Water in the Atmosphere ; Cloud formation leads to precipitation.  Humidity: Amount of water in air.  Relative Humidity: Percent of water in air compared to amount it holds. Psychrometer: measures relative humidity.  Dew Point: Temperature when water condenses out of air, clinging to particles, and forms clouds.

Local Winds: Unequal heating of land and water, smaller area, changes  Local Winds can be found near a large body of water and around mountainous areas.  Sea breezes: Occur during the day time when warm air rises from the land and is replaced by cooler air coming from the sea.  Land breezes: Occur at night when cool air from land blows out to replace warmer air rising from sea.  Mountain breezes: Winds and air masses are funneled up the mountain during the day and directed down the mountain at night when cooler.

Global Winds: Unequal heating of globe, larger area, steady.  Warm air rises near equator and falls at poles creating wind belts.  Coriolis Effect: Due to rotation of the Earth winds do not follow a straight path. Northern hemisphere: Turns to right. Southern hemisphere: Turns to left.  3 major belts: Trade winds: Blow from NE to SW Prevailing Westerlies: Blow from SW to NE Polar Easterlies: Blow away from poles, East to West

Other Areas  Areas of Inactivity due to rising or falling air masses. Doldrums: Rising air near equator. Horse Latitudes: Falling air (30 degrees North).

Types of Clouds: According to height & Type  Cumulus: Form less than 2 km but can reach 18km. Fluffy, piles of cotton. (Fair Skies) Cumulonimbus: Towering clouds that produce thunderstorms. Altocumulus: Very high cumulus clouds.  Stratus: Flat layers, cover the sky. Nimbostratus: Thicken producing rains or snow.  Cirrus: High altitudes above 6km. Wispy feathery. Made of ice crystals.

Air Masses according to temp and humidity  Polar = Cold air from the poles.  Tropical = Warm air from the equator.  Maritime = Moist air forms over water.  Continental = Dry air forms over land.