Atmosphere: Clouds, Pressure Systems, Wind Belts

Bell Work What is the difference between heat and temperature? 1/27/16 What is the difference between heat and temperature? How does temperature affect the movement of air? Get the air masses and fronts worksheet out to review (do NOT turn in) Get your notebooks out for the notebook quiz

A B C Bell Work What type of front is shown in A? How do you know? 1/28/16 A Bell Work What type of front is shown in A? How do you know? What type of front is shown in B? How do you know? Identify each of the front symbols shown in C. B C

Clouds A collection of water droplets or ice crystals formed when water vapor condenses into condensation nuclei.

Cloud names: Alto-: clouds at middle altitudes Cirro-: clouds that form at high altitudes Nimbo- or -nimbus: clouds likely to produce precipitation Cumulo-: piled up clouds Strato-: layered clouds

Stratus clouds: Form in layers Cover large areas Nimbostratus clouds: Dark stratus clouds Produce continuous rain

Cumulus clouds: Puffy, white clouds with flat bottoms When small indicate fair weather When large (Cumulonimbus) produce stormy weather

Cirrus Clouds: Thin, feathery, white clouds Found at high altitude When they get thicker, a change in weather is coming

Fog: stratus cloud that formed close to ground Contrails: clouds formed when water vapor condenses around particles in aircraft exhaust

Heat: energy transfer between moving molecules Heat energy can be transferred in 3 ways: Radiation: transfer of energy through electromagnetic waves (e.g. the sun)

Conduction: transfer of heat energy through a solid object e. g Conduction: transfer of heat energy through a solid object e.g. a blacksmith heating metal to change its shape

Convection: transfer of heat energy through movement of a liquid or gas Water when it boils Magma in Earth’s mantle Ocean currents Air in the atmosphere

Pressure: Force applied perpendicular to an object Atmospheric Pressure: Force applied against a surface by the weight of the air above

Atmospheric Pressure Systems High Pressure System: Cool air moves in and sinks Winds blow out away from high pressure Isobars: Lines of equal pressure

High Pressure System: Surface winds spiral outward from center – blow clockwise in Northern hemisphere Brings fair, dry weather

Low Pressure System: Hot air rises leaving a void (empty space) Winds blow in toward center of low pressure

Low Pressure System Winds blow Counter-clockwise in Northern hemisphere Bring clouds & precipitation

Cyclones: Occur where a lower pressure area is surrounded by higher pressure areas Air spirals towards center of low pressure Marked by L on weather map Bring clouds and rain or snow

Anticyclone: A rotation of air around an area of high pressure Air spins clockwise away from center of the high pressure Marked by H on weather map Brings fair weather

Bell Work 2/1/16 1. Read the article: “Auroras in the Night Sky” 2. Answer the questions on the ½ sheet of paper

Global Pressure Cells Hadley Cell: Warm air at the equator rises, moves towards the poles, cools, sinks at ~30° north & south of equator then moves back towards equator.

Polar cell: Cold air at the poles sinks, moves away from pole, warms, rises at about 60°N or south and moves back toward poles

Ferrel cell: Sinking cold air at convergence with the Hadley cell moves north Warmer air is pushed up at convergence with the air coming from the Polar cell

Wind: movement of air caused by differences in air pressure ↑ pressure difference → ↑ wind speed Temperature (heat energy) affects air pressure: Warm air rises - ↓ pressure Cold air sinks - ↑ pressure

Global Wind Systems: caused by Pressure gradients in Cells Coriolis Effect

Polar Easterlies: winds blow EAST to WEST from the poles to 60⁰ N. & S. of equator

Westerlies: Winds blow from 30° latitude WEST to EAST towards polar easterlies in both hemispheres

Trade Winds: Winds blow from 30° latitude EAST to WEST towards the equator in both hemispheres

Jet streams Narrow belts of high speed winds (up to 400 km/h) in the upper troposphere and lower stratosphere.

Doldrums: Located along the equator; no winds blow; rising air & low pressure Horse Latitudes weak winds at 30 N and 30 S of equator

Bell Work North Carolina is at latitude 35.5°N of the equator. 1. What wind belt blows over us? 2. From what direction do the winds blow?

Cold front: Rainfall can be torrential and wind speeds can be high Cold front: Rainfall can be torrential and wind speeds can be high. Blue lines with triangles on one side represents cold fronts on weather maps. The direction the triangles point is the direction in which the cold front is moving.

Warm front: Brings a gradual increase in rainfall followed by clearing and warming after the front passes. Can bring prolonged rain. A red line with semi-circles on one side represents warm fronts. The side the semi-circles are on represents the direction the front travels.

Occluded front: Formed when a cold front overtakes a warm front Occluded front: Formed when a cold front overtakes a warm front. Weather events depend on whether it is a warm or cold occlusion. An occluded front usually brings heavy precipitation and changing wind directions. A purple line with semi-circles and triangles both on the same side represents occluded fronts and shows the direction of travel

Stationary front: Indicates a non-moving boundary between two different air masses. These fronts have long continuous rainy periods that linger for extended periods in one area and move in waves. A semi-circle bordering one side and triangles along the opposite side represents that the front is not moving in any direction.