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Atmosphere, Clouds & Weather. What is Atmosphere?. Atmosphere is the mixture of gases that surrounds a planet, such as Earth Our Atmosphere is made of 78% Nitrogen, 21% Oxygen, .9% Argon, and .1% Other gases. Ozone. O. O. O.
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What is Atmosphere? • Atmosphere is the mixture of gases that surrounds a planet, such as Earth • Our Atmosphere is made of 78% Nitrogen, 21% Oxygen, .9% Argon, and .1% Other gases
Ozone O O O • You probably have heard of ozone before, but do you really know what it is?? • Ozone is a gas molecule in our atmosphere that consists of 3 oxygen atoms (O3) • Ozone is very important to our atmosphere because the atmosphere’s ozone layer absorbs harmful ultraviolet rays that could damage many of Earth’s plants and animals
What Prevents our Atmosphere from just floating off into space?? • Earth’s gravity holds the gases of the atmosphere near Earth’s surface • Due to this pull, the atmosphere also puts pressure on Earth known as Atmospheric Pressure • Because pressure can change due to amount of water vapor in the air or the temperature, meteorologists can measure atmospheric pressure with an instrument called a barometer.
Layers of the Atmosphere Activity! Atmosphere Webquest
Solar Energy and the Atmosphere • The Sun’s energy travels between the Sun and Earth as radiation • There is radiation that we can see but also forms we cannot see, like ultraviolet light, X-rays, and radio waves, gamma rays • Our atmosphere affects radiation by absorbing or reflecting most of the radiation listed that we cannot see (some is reflected by the ground also)
Similar to the way an actual green house works…the glass of a green house allows visible light and infrared rays to pass through but the glass also prevents them to escape back out • Without an adequate ozone layer to prevent many of the rays of the sun from getting to the Earth, our atmosphere can act as a greenhouse to trap that radiation heat in
Atmospheric Moisture Water in our atmosphere appears in 3 ways: • Water vapor • Ice • Water (liquid) Are you familiar with the water cycle on Earth??
Humidity • Humidity is just another name for water vapor in the atmosphere. • Scientists use an instrument called a psychrometer to measure humidity
Dew Point • This is the temperature at which the rate of condensation equals the rate of evaporation • Anything below this temperature will cause condensation to occur, like when you see dew on grass in the morning.
Clouds Clouds form when water vapor condenses in the trophosphere Main Types of Clouds: • Stratus • Cumulus • Cirrus
Let’s Practice by making our own cloud and then identifying clouds on a worksheet and outside today!
View Various Cloud powerpoint examples • Do the “Make your own Cloud” activity • Types of Clouds Worksheet
Fog • Like clouds, fog happens when water vapor in the air condenses. • Normally fog happens when the layer of air in contact with the ground becomes chilled below dew point. This normally happens in areas of low elevation (valleys and such) • Fog also forms near oceans or other bodies of water because either the land is cooler than the water or the water is cooler than the land
Precipitation Anything made of water that falls from the sky is considered precipitation
Measuring Precipitation • Some people use a rain gauge to measure rainfall…you can even buy a simple one at the local store! • A more complex way to measure precipitation is through Dopplar Radar. • Dopplar radar is used to predict the location, direction of movement and intensity of the precipitation
Weather • Lightning • Tornadoes • Rain • Snow • Hurricanes Why do these things occur? How do we predict weather?
Air Masses • Continental Air Masses are those that form over land and often bring dry weather conditions when they move into another region • Maritime Air Masses form over oceans and are moist. They take on the characteristics of the water over which they form. They cause precipitation and fog as they move to another region
Severe Weather • Thunderstorms • Lightning • Hurricanes • Tornadoes
Thunderstorms • The two most basic elements that cause a thunderstorm to develop are: moisture and rapidly rising warm air • Because moisture and warmth are crucial to thunderstorms, it makes sense that they would occur more often in the spring and summer
Lightning • Clouds contain millions of water droplets and ice particles. These droplets collide electrons are knocked off then gather at the lower portion of the cloud, giving it a negative charge. The rising moisture that has lost an electron carries a positive charge to the top of the cloud. • The charges at the top and bottom of the cloud increase, making the electrons at the Earth's surface are repel deeper into the Earth by the negative charge at the lower portion of the cloud. This repulsion of electrons causes the Earth's surface to acquire a strong positive charge. • All that is needed now is a path so the negative cloud bottom can conduct its electricity to the positive Earth surface. The strong electric field creates this path through the air, resulting in lightning.
Hurricanes • A hurricane is a severe storm that develops over tropical oceans and whose strong winds of more than 120 kilometer per hour spiral toward the intensity low pressure storm center • Hurricanes begin when warm, moist air over the ocean rises rapidly. When this warm air condenses, a large amount of energy is released in the form of heat which increases the force of the air
Tornadoes • A tornado is a destructive rotating column of air with high wind speed and is visible as a funnel-shaped cloud • Tornadoes form when a thunderstorm meets with high, sideways winds • These winds cause the rising air to rotate • Winds can reach speeds up to 400 kilometers per hour!
Weather Maps and Symbols • Meteorologists use weather symbols to create a station model for the weather at a particular weather station • These symbols are more easily seen and take up less room than words. What does this mean??
Let’s do some Weather Symbol Practice (Weather Symbol wksht)
Fronts • Cold Fronts happen when a cold air mass overtakes a warm air mass • Warm Fronts happen when a cold air mass retreats from an area and gradually warm air takes over, often producing precipitation • Stationary Fronts are air masses that move slowly or not at all • Occluded Fronts form when a cold air mass overtakes a warm air mass and lifts it off the ground and over another air mass
Weather Forecasting • Meteorologists use satellite images and Doppler radar to get important information that helps them predict weather by making weather models with a computer. • They have to be careful when interpreting the models because the information they receive is very general. • Using more than one model can help meteorologists and simulating possible errors can help them be more accurate in their weather predictions
Types of Forecasts • Daily—the current day’s forecast • Extended—looks ahead 3-7 days • Long-range—Covers monthly and seasonal periods
Severe Weather—What to Do? FOR ALL STORMS: Have a kit ready: radio, batteries, flashlights, rain gear, blankets bottled water, food and medicines. Listen for weather updates THUNDERSTORM—Stay indoors, avoid electrical appliances, running water metal pipes and phone lines. If outside, avoid tall objects and bodies of water. Get into a car if that is your only way to get “indoors”. TORNADOES—If you need to take cover (see tornado warning below), go to the basement, storm cellar, or small inner room that has no windows. If outside, lie in a low-lying area (like a ditch). Protect your head and neck. Tornado watch- Tornadoes are possible in your area. Stay tuned to the radio or television news. Tornado warning- A tornado is either on the ground or has been detected by Doppler radar. Seek shelter immediately!
Severe Weather—What to Do? Hurricane—Secure loose objects, doors and windows (some people have “hurricane shutters). Plan and practice an evacuation route. Be prepared to follow instructions from weather updates. Stay indoors and away from areas that are likely to have flying debris or other dangers Blizzard—Make sure you have a way to safely make heat in the event of power outages. Stay indoors. Dress warmly. Avoid walking or driving in icy conditions
