310 likes | 400 Views
Weather. Honors Earth Space Science. Weather.
E N D
Weather Honors Earth Space Science
Weather... You can’t see me, but you feel me, you can’t touch me, but I can touch you. I have been called the “Breathe of the Gods”, or the killer and giver of life, gentle and fierce, friendly and enemy, angry and happy. The Native Americans called me Moriah, and Snow Eater (Chinook). The Japanese call me Kaze and in Russia I am called Veter. I can shatter homes, or wake a child from a peaceful sleep or bring relief in times of need. I can spread the most dreaded diseases or bring a welcome freshness. What am I?
Weather & Climate Definitions • Weather- “the state of the atmosphere with respect to heat or cold, wetness or dryness, calm or storm, clearness or cloudiness”. • Climate – “the average course or condition of the weather at a place usually over a period of years as exhibited by temperature, wind velocity, and precipitation”
Main points to remember as we learn about weather: • The sun warms the earth’s surface and therefore all the air above the surface • The earth is warmed most at the equator and least at the poles---why? • The air above land is warmed more quickly than air above water. • Warm air expands and rises, creating an area of low pressure; cold air is dense and sinks, creating an area of high pressure
Weather Factors • Weather: The state of the atmosphere at a specific time and place TEMPERATURE= the average motion of molecules ↑ TEMP= ↑movement of molecules= feels hot ↓ TEMP= ↓movement of molecules= feels cold
Air Pressure • Warm air= expanding or rising air= leaves behind Low pressure • Cold Air=sinking air= leaves an area of High pressure
High Pressure • Higher pressure than what is normal for that altitude. • What do you notice about the air in this region? • Brings clear skies and fair weather. • The sinking cold air warms as it does so and becomes stable. Picture taken from: http://www.windows.ucar.edu/tour/link=/earth/Atmosphere/high_pressure.html
Low Pressure • A low pressure region (depression or cyclone) is caused by rising air. • Clouds, rain, and very strong winds occur. • Why do you think that is? Picture taken from: http://www.windows.ucar.edu/tour/link=/earth/Atmosphere/low_pressure.html
What causes winds? • Uneven heating of the earth’s surface causes some areas to be warmer than others. • As we know, warm always follows cold to share it’s warmth- when this happens in the atmosphere, wind happens!
Wind movement • A wind is a horizontal movement of air from a area of high pressure to an area of low pressure • It is this difference in pressure that makes the air move=wind • Winds are measured by direction and speed • The anemometer is the tool we use to measure this
Global Circulation and Wind Systems • Solar energy is at its greatest around the equator---Why? • Greater exposure to direct sun light. In other words, it receive the highest amount of solar energy.
Some or the air moves back towards the equator as it sinks... • Tradewinds: Where do you think they got their name? Who were these winds particularly important to?
Cloud Types Picture taken from: http://commons.wikimedia.org/wiki/File:Cloud_types.jpg
Cloud Formation • Clouds form when water vapor condenses on dust, salt particles in the air • The temperature in which condensation begins is called the dew point
TYPES OF CLOUDS • Cirrus Clouds: wispy, feathery clouds Form only at high levels, therefore are made of ice crystals
Types of Clouds • Cumulus Clouds: are puffy white cotton ball looking clouds
TYPES OF CLOUDS • Cumulonimbus Clouds: These are thunderstorm clouds
Types of Clouds • Stratus Clouds: clouds that form in flat layers- cover all or most of the sky and are low level clouds
Air Masses • Air masses are masses of air that have the same characteristics of the surface over which it develops • Pressure Systems descending (going down)=H pressure ascending (going up)=L pressure
Air Masses Air Masses: An air mass is a huge body of air with similar air temperature and humidity throughout.
The air temperature and humidity is determined by WHERE the air mass formed.
The 4 Weather Fronts • Warm front • Cold front • Occluded front • Stationary Front
Fronts: the boundary between 2 air masses This is the symbol on a map for a warm front • Warm Front: warm air slides over departing cold air- large bands of precipitation form
This is the symbol for a cold front Cold Fronts • Cold air pushes under a warm air mass. Warm air rises quickly=narrow bands of violent storms form
This is the weather map symbol for an occluded front Occluded Front • 2 air masses merge and force warm air between them to rise quickly. Strong winds and heavy precipitation will occur
This is the weather map symbol for a stationary front Stationary Front • Warm or cold front stops moving. Light wind and precipitation may occur across the front boundary
Reading a weather map • ISOBAR= connects areas of equal pressure BAR comes from BARometric pressure
Reading a weather map... • Isotherm: Connects areas of equal temperature; therm means temperature