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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.
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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
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
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.
Clouds: Five Types of Clouds 1. High-Level Clouds: Usually found at greater than 20,000 ft. • Usually made of ice crystals • Examples include Cirrus, Cirrostratus
Clouds: Five Types of Clouds 2. 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 Clouds 3. Low-Level Clouds: Usually found lower than 6,500 ft. • Low, lumpy clouds that produce weak to moderate precipitation • Examples include Nimbostratus and Stratocumulus
Clouds: Five Types of Clouds 4. 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 NSF North MississippK-8
Clouds: Five Types of Clouds 5. 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