16.1 weather and atmospheric water. learning targets 1.discuss the difference between weather and...
TRANSCRIPT
Learning Targets
1. Discuss the difference between weather and climate
2. Describe the relationship between air temperature and humidity, including the concept of dew point
3. List the basics of the different cloud types and what they indicate about current and future weather
4. Explain how the different types of precipitation form
Weather vs. Climate
1. Weather: condition of the atmosphere at any given time
2. Climate: long term averages of weather
Weather
1. Weather depends on:a) Air temperatureb) Air pressurec) Dew pointd) Humiditye) Cloud coverf) Precipitationg) Wind speed and direction
2. All are directly related to amount of energy in system
Humidity
1. Humidity - Amount of water vapor in air
a) Usually ~3%
2. Relative humidity - % of water vapor certain volume of air is holding relative to maximum amount it can contain
Humidity
1. Precipitation occurs when relative humidity is over 100%
2. Dew point = 100% humidity
3. Two ways to reach dew pointa) Lower temperatureb) Increase water content
Clouds
1. Clouds form when air reaches its dew point2. Serve several roles
a) Preventing solar radiation from reaching ground
b) Absorbing warmth that is re-emitted from ground
c) Source of precipitation3. Classified based on height
a) Strato (low), Alto (middle), Cirro (high)4. Classified based on shape
a) Cumulus, stratus, cirrus
Fog
1. Radiation foga) Cold ground cools air beyond its
dew pointb) Most common
2. Steam foga) Forms over lakes and ponds at
night because water is warm and air is cool
Precipitation
1. Dewa) Warm air contacting cold surface
2. Rain/Snowa) Drops/flakes too heavy to be held up
by air currentsb) Melt or remain frozen depending on
temperature
3. Haila) Extremely strong currents push water
back up into the cloud several times