Moisture in the Air MOISTURE IN THE AIR
Jan 11, 2016
Moisture in the Air MOISTURE IN THE AIR
Weather
• Present state of the atmosphere and current conditions
Climate
• Weather over a long period of time
• Example: Subtropical, desert, etc….
Factors that influence weather
• Temperature• Amount of moisture in air• Air pressure• Wind
Water Cycle
Precipitation
• Falling water out of sky• Water droplets stay small will stay suspended
in clouds• When water droplets reach > 0.2 mm they fall
out of sky as precipiation
Types of precipitation
• Rain, snow, sleet, and hail• Air temperature determines what will fall out
of sky• Above freezing (32oF) = rain• Below freezing = snow• Water freezes as ice = hail• Snow, then melts, then refreezes = sleet
Snow
Sleet
Freezing Rain
Humidity
• Amount of water in the air• Depends on temperature– High temp. – more water air can hold– Low temp – less water air can hold
– CHANGES IN HUMIDITY INDICATE CHANGES IN WEATHER
Relative Humidity
• Measure of amount of water vapor in air compared to total amount of water vapor it has room for at a particular temperature
• Stated as a percent• Example: 50 % humidity – air is only holding
50% of the water vapor that it can hold
Saturation
• When air is holding all the moisture it can at a particular temperature
• Saturated air = 100% humidity
Dew point
• Temperature at which air is saturated and condensation takes place.
Clouds
• Made of millions of water droplets• Form as humid air is cooled and reaches its
dew point and condenses• Condensed water vapor forms tiny drops of
water around dust particles in atmosphere• Millions get together = cloud
Clouds are classified into a system that uses Latin words to describe the appearance of clouds as seen by an observer on the ground.
Latin Root Translation Example
cumulus stratuscirrusnimbus
heap layercurl of hairrain
fair weather cumulus altostratuscirruscumulonimbus
Clouds: Five Types of Clouds1. High-Level Clouds: Usually found at greater than 20,000 ft.
Usually made of ice crystals
Examples include Cirrus, Cirrostratus
Clouds: Five Types of Clouds2. Mid-Level Clouds: Usually found between 6,500 and 20,000 ft.
Usually made of water droplets, but can be made of ice
Example is altocumulus
Clouds: Five Types of Clouds3. Low-Level Clouds: Usually found lower than 6,500 ft.
Low, lumpy clouds that produce weak to moderate precipitation
Examples include Nimbostratus and Stratocumulus
NSF North MississippK-8
Clouds: Five Types of Clouds4. Vertically developed: These clouds are thick and puffy and extend very far upwards
Examples include Cumulonimbus and Fair Weather Cumulus
Ordinary Cumulus clouds can quickly become Cumulonimbus clouds that start strong thunderstorms
Clouds: Five Types of Clouds5. Other: These are miscellaneous clouds
These clouds do not really fit into any category, and all have different characteristics
Examples include billow clouds, contrails, mammatus, orographic, and pileus