32 terms

Weather Basics

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Weather
The condition of the Earth's atmosphere at a particular time and place.
Precipitation
A form of water that falls from clouds to the Earth in the form of rain, snow, sleet, etc.
Temperature
A measure of how hot or cold an object is compared to a reference point.
Ozone
The form of oxygen that has three atoms of oxygen instead of the usual two.
Air Pressure
A force that is the result of the weight of air pushing on an area. The further up you go in elevation, the less there is.
Atmosphere
The envelope of gases that surrounds the Earth.
Barometer
A device that is used to measure air pressure.
Climate
The weather conditions prevailing in an area in general or over a long period.
Altitude
The distance in the atmosphere.
Air Mass
A huge body of air that has similar temperature, humidity, and air pressure at any given height.
Jet Stream
Bands of high-speed winds that move at about 10 km above Earth's surface that move from west to east. This helps fronts move and airplanes to move faster or slower depending on the direction traveling.
Elevation
The distance above sea level when standing on Earth.
Front
The boundary where unlike air masses meet.
The atmosphere is composted of a mixture of atoms and molecules of different kinds. Nitrogen 78%. Oxygen 21%. Other/Trace gases 1%.
What is the composition of the atmosphere? Include their %.
The importance of the atmosphere and its gases is:
• To keep the Earth warm
• Make Earth livable for living things
• Protect the Earth from harmful radiation and meteors from space
Why is the atmosphere important?
Troposphere
The first main layer closest to the Earth (0-12 km) where most weather occurs; temperature decreases as you go up.
Stratosphere
Second main layer (12-50 km) where airplanes fly and contains the ozone layer; temp increases as you go up.
Mesosphere
Third main layer (50-80 km) where meteoroids burn up; temp decreases as you go up - coldest layer.
Thermosphere
Top or fourth main layer (80+ km) divided into 2 sublayers; temp increases as you go up - hottest layer.
Ionosphere
First sublayer (80-400 km) where radio waves are reflected back to earth and auroras occur. There are electrically charged gas molecules in this layer.
Exosphere
Top sublayer (400+ km) where satellites orbit. It is the part that is the hottest.
Density. The further up you go in elevation, the less dense air is. This makes it hard for mountain climbers to breathe as their elevation increases.
The relationship between mass and volume. Mass divided by volume.
Air
Can be compressed, has mass and takes up space. It does NOT get all of its heat DIRECTLY from the sun.
The sun is the source of the Earth's energy. The oceans and land absorb solar energy. The oceans make up about 70% of the Earth's surface.
What are some characteristics of and what is the relationship between the sun, ocean, and energy?
Cold Front
When a cold air mass takes over a slow-moving warm mass; storms come with it.
Warm Front
When a warm air mass overtakes a slow-moving cold mass; causes steady, long-lasting rains in the summer and steady snowfalls in the winter
Stationary Front
Occurs when warm and cold masses meet but neither can move the other (no movement).
Occluded Front
When a warm air mass is caught between two cooler air masses; it is the least common.
Unequal heating occurs along the shores of large bodies of water. It takes more energy to warm up a body of water than it does to warm up an equal area of land. As the sun heats Earth's surface during the day, the land warms up faster than the water. As a result, the air over the land becomes warmer than the air over the water. At night, the process is reversed and the land cools off faster than the water.
Describe what happens during a sea breeze and land breeze.
Sea Breeze
Air warms when it is over the land and rises to a lower pressure area. As it rises, it moves over a body of water and cools. When it cools, it gets pushed down.
Land Breeze
Air warms when it is over a body of water and rises to a lower pressure area. As it rises, it moves land and cools.
Density and Pressure
What two characteristics help determine the layers of the atmosphere?