Layers of the Atmosphere
The atmosphere is primarily made up of which 2 gases? What is the amount of each?
Nitrogen - 78% and Oxygen 21%
What the difference between evaporation and condensation?
Evaporation is when liquid water is heated and turns into water vapor. Condensation is when water vapor cools and turns into liquid water.
Air masses are huge bodies of air that have similar _____________, ____________ and ____________.
Temperature, humidity and air pressure.
What is a scientist who studies and predicts weather called?
A meteorologist
How and when do thunderstorms form?
Thunderstorms form warm air carrying lots of moisture is forced upward along a cold front. Positive and negative electrical charges build up and discharge. Thunderstorms typically form in the summer.
In which layer of the atmosphere does Earth's weather occur?
The troposphere
How does the temperature of the air effect condensation and dew point?
Warm air can hold more water vapor than cold air. Therefore, as air cools, the amount of water vapor it can hold decreases and the water vapor starts to condense.
What two factors influence how air masses move? In what direction to air masses move over the continental US?
What are four tools used to predict weather?
Weather satellites, weather balloons, weather stations and computer forecasts.
How and when do hurricanes form?
Hurricanes form over the ocean in late summer. Warm humid air near the water's surface rises and draws in surrounding air. Band of heavy rain and high winds form.
As altitude (the distance above sea level) increases, air pressure ____________
Decreases
What is relative humidity? During what time of year is it highest? How is it measured?
Relative humidity is the percent of water vapor in the air compared to the maximum amount of water vapor the air can hold. It is higher in the summer than in the winter. It is measured with a device called a psychrometer - a device made of two thermometers - one with a wet bulb and one with a dry bulb.
What are the four types of air masses? Describe each.
Continental polar and Continental tropical - Both are formed over land and are both are therefore dry. Continental polar is dry and cold, because they form over a colder area. Continental tropical is dry and hot because they form over hot areas. Maritime polar and maritime tropical. Both are formed over water and are therefore wet. Maritime polar is wet and cool because they form over colder areas and maritime tropical is wet and warm because they form over warmer areas.
If you see a high pressure symbol on a weather map what does this tell you about the weather in that area? What about low pressure?
High pressure means the skies will be clear. Low pressure means the skies will be cloudy and it might rain or storm.
How and where do tornadoes form?
Tornados form from thunderstorms. They can form from a fast spinning column of air that turns vertical. They are most common in the Great Plains.
What causes wind? What is the difference between local winds and global winds?
Wind is caused by unequal heating of the Earth's surface. Local winds are caused by unequal heating over small areas. Global winds are caused by unequal heating over much larger areas, from the equator to the poles.
What are three ways that water vapor enters the atmosphere? Explain each.
evaporation - when liquid water in lakes rivers and other bodies of water is heated by the sun, transpiration - when water is released by the laves of plants, and respiration - where animals and people release water vapor into the air when they breathe out.
What are the four types of fronts? How do they form? What kind of weather does each bring?
Warm fronts form when fast moving warm air overtakes slower moving cold air. They bring light rain or snow that may last a long time.
Cold fronts form when a cold air mass runs into a warm air mass. They bring heavy rain, wind and thunderstorms that usually pass quickly.
Occluded fronts form when a warm air mass gets caught between two cold air masses. They bring clouds, rain or snow.
Stationary fronts are caused when a warm air mass and cold air mass meet but neither can move the other. They bring many days of clouds or precipitation.
What kind of weather would you expect if you see a cold front moving into an area? What about a warm front?
Cold fronts bring heavy rain and thunder that move quickly. Warm fronts bring light and a drizzle that can last a while.
How and where do lake effect winter storms form?
Lake effect storms form over the great lakes. They usually form in early winter when the lake temperatures are still warmer than the air temperature. When cold air moves from Canada over the lakes, it picks up moisture from the lakes and rapidly cools it so that it condenses and falls as snow.
Explain how Earth's atmosphere keeps the temperature of Earth stable.
About 30 percent of the solar energy that arrives at the top of the atmosphere is reflected back to space by clouds, atmospheric particles, or bright ground surfaces like sea ice and snow. About 20 percent of solar energy is absorbed in the atmosphere by water vapor, dust, and ozone, so only 50% reaches the Earth's surface.
Explain how hail, sleet, freezing rain and snow are alike and different.
Hail, sleet, freezing rain and snow are all types of frozen precipitation. Hail is pellets of ice made when updrafts of wind carry precipitation thorough cold regions many times causing ice to build up. Freezing rain is when raindrops freeze when they fall on cold surfaces. Sleet is when raindrops fall through layers of air below freezing before they hit the ground. Snow forms when water vapor in a cold is converted directly into ice crystals.
What kind of weather does high or rising barometric pressure bring? What kind of weather does low or falling barometric weather bring? (Think of the cloud in a bottle experiment.)
High or rising pressure will bring clear skies. Low or falling pressure will bring clouds and precipitation.
If you see a stationary front on a weather map, what does that tell you?
Stationary fronts mean there is likely to be precipitation and clouds for several days.
What are some storm safety tips for various storms?
Tornado - move to the middle ground floor of the house. Stay away from windows and doors.
Thunderstorms - Get or stay indoors. If outside, find a low lying are away from trees, fences and poles.
Winter Storm - Stay inside, don't drive, dress warm, keep food and water on hand in case of power outages.
Hurricanes - Be prepared to evacuate.