12.1 - Water in the Atmosphere
Relative humidity can be measured with an instrument called a psychrometer.
What is relative humidity and how is it measured?
Scientists classify clouds into 3 main types based on their shape: cirrus, cumulus, and stratus. Clouds are further classified by their altitude.
What are the 3 main types of clouds?
Any form of water that falls from clouds and reaches Earth's surface. It is the most vital part of the water cycle.
What is precipitation?
Four major types of air masses influence the weather in North America: maritime tropical, continental tropical, maritime polar, and continental polar.
What are the major air masses?
Scientists who study and predict weather
What are meteorologists?
The percentage of water vapor in the air compared to the maximum amount of water vapor the air can hold at a particular temperature.
What is relative humidity?
The temperature at which condensation begins.
What is the dew point?
Precipitation include rain, sleet, freezing rain, snow. and hail.
What are the common kinds of precipitation?
Colliding air masses can form four types of fronts: cold fronts, warm fronts, occluded fronts, and stationary fronts.
What are the major types of fronts?
Using maps, charts, computers, and other technology to analyze data.
How can you predict the weather?
In the water cycle, water vapor enters the atmosphere by evaporation from the oceans and other bodies of water and leaves by condensation.
How does water move through the atmosphere?
Clouds form when water vapor in the air condenses to form liquid water or ice crystals.
How do clouds form?
An open-ended tube that collects rain.
What is a rain gauge?
Cyclones and decreasing air pressure are associated with clouds, winds, and precipitation. The descending air in an anticyclone generally causes dry, clear weather.
What weather do cyclones and anticyclones bring?
Standard symbols on weather maps show fronts, areas of high and low pressure, types of precipitation, and temperatures.
What can you learn from weather maps?
A _______ has 2 thermometers, a wet-bulb thermometer and a dry-bulb thermometer.
What is the psychrometer (composed of?)
Cooling of the air can change the water vapor into droplets.
What is the role of cooling?
Rain is measured by either dipping a ruler into a rain gauge or by reading a scale. Snow is either measured by using a. measuring stick or collecting melting snow and measuring the depth of water it produces.
How is precipitation measured?
If you are caught in a snowstorm, try to find shelter from the wind. During thunderstorms, avoid places where lightning may strike. Also, avoid objects that can conduct electricity, such as metal objects and bodies of water. If you hear a hurricane warning and are told to evacuate, leave the area immediately. The safest place to be during a tornado is in a storm shelter or basement.
How can you stay safe in a storm?
Lines joining places on the map that have the same air pressure and temperature.
What are isobars and isotherms?
The __________________ can be found by comparing the ______________ of the wet-bulb and dry-bulb thermometers.
Explain how relative humidity determined.
For water vapor to condense and form clouds, tiny particles must be present in the atmosphere so that water has a surface on which to condense.
What is the role of particles?
Small or large, many floods, occur when the volume of water in a river increases so much that the river overflows its channel. Droughts are usually caused by dry weather systems that remain in one place for weeks or months at a time.
What are the causes and effects of floods and droughts?
All year around, must precipitation begins in clouds as snow. If the is colder then 0*C all the way to the ground, the precipitation falls as snow. (Blizzard) Thunderstorms form in large cumulonimbus clouds. A hurricane begins over warm ocean water as a low-pressure area, or tropical disturbance. Tornadoes most commonly develop in thick cumulonimbus clouds that produce thunderstorms.
How do different types of storms form?
Automated weather stations, weather balloons, weather satellites, and computer forecasts.
What kinds of technology are used to measure weather?