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METEOROLOGY
1. WEATHER The condition of Earth’s atmosphere at a particular time and place.
2. ATMOSPHERE Layer of gas that surround the Earth.
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Makes conditions on Earth suitable for life by :
N
O
CO2
Water vapor:
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DRY AIR VS WET AIR- Relative Humidity: Psychrometers
3. AIR POLLUTION Most of the pollution comes from
 Next most pollution comes from
 Natural sources: salt (ocean and land), dust, forest fires, pollen, ash (volcanoes)
4. PRESSURE
 AIR PRESSURE – Force of the atmosphere
 Two type of Barometers mercury and aneroid (airtight metal chamber with sensitive metal)
 760Mm of Hg, millibars = 1inch=34 millibars, ATM
5. ALTITUDES AND AIR DENSITY At higher altitudes there is _________ pressure, which means less _____________.
The density of the air _______________
6. LAYERS OF THE ATMOSPHERE
The four main layers are classified according ________________________
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Troposphere- lowest – where earth’s weather occurs. (9-16km above the planet, 0-12 Poles and equator)
As altitude increases temperature_______________
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Stratosphere: (12 to 50km) divided into 2 layers – lower and upper stratosphere
The upper stratosphere is warmer than the lower because ________________
Most ________________________ at this altitude because of the decreased pressure. (Why?)
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Mesosphere: (80km- ?)
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__________________ layer of the atmosphere.
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Most meteoroids burn up here. (How do meteors burn up in the coldest layer?)
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Thermosphere: (80-550km and to the end)
The density is one thousand times less compared to sea level- 1cm3 of air in this room would expand to
100,000 cm3.
Very high temperatures (1800 degrees C) but does not feel hot. (Why?)
Sun strikes here first- N & O convert energy to heat
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The Thermosphere is divided into two layers :
Ionosphere- (80-550) – ions are created- radio waves bounce off the ions________________________________________________________
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Exosphere- (550)- _________________________________________
7.
ENERGY FROM THE SUN
Visible light (longer than red), Infrared radiation, Ultraviolet radiation (shorter than purple).
8. ENERGY IN THE ATMOSPHERE
Some of the energy is absorbed by the atmosphere (clouds, dust, gas), but most of the energy reaches the
Earth.
Some of the energy that is absorbed by the earth is radiated back into the atmosphere as infrared radiation.
This energy forms a “blanket” that holds heat in. The process of holding the heat in is called the
_________________________________. (How does the heat energy enter the atmosphere but is prevented
from leaving?)
9. TRANSFER OF HEAT
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Radiation:
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Conduction:
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Convection:
10. WIND:
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Wind is the ____________________________________________________
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_________________________ causes the difference in pressure. The sun strikes the Earth at
different angles. The same amount of energy is spread out over a larger area, which means less heat
per area.
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Air that is heated expands and becomes ____________ which means less pressure and also rises. Air
that is cooler is denser which means _________________________. Also the cool air moves under
the warm air causing it to rise
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Local wind - winds that blow over short distances.(Sea Breeze, Land Breeze)
Global Winds: Wind over long distances. The movement of air between the equator and the poles
produce global winds due to the unequal heating of the earth. Doldrums, Horse Latitudes, Trade
Winds, Prevailing Westerlies, Polar Easterlies, Jet Stream.
11. CLOUDS
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Form when water vapor in the air becomes liquid water or ice crystals.
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Cold air holds less water than warm air.
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Dew Point- The temperature at which water precipitates out of the air.
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Clouds release water or ice crystals depending on temperature.
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Clouds form whenever air is cooled to its dew point.
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Cumulus- rounded puffy clouds that form less than 2km above the ground usually indicate fair
weather. Towering clouds with flat tops are called cumulonimbus.
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Stratus- clouds that spread out that covers most or all of the sky. If they thicken and produce drizzle
rain or snow then they are called nimbostratus.
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Cirrus- wispy feathery clouds form at high levels (6km) made mostly of ice crystals
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Could also use the prefix “alto” to show that the clouds are at middle altitudes. (2-6km).
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Clouds near the ground are called Fog.
Precipitation-
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Rain- water droplets that is bigger than .5mm in diameter. Smaller drops called mist or drizzle. Form
usually from nimbostratus clouds.
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Sleet- Rain that fall through a layer of air below 0 degrees and freeze as they fall.
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Hail- large ice pellets that form only inside cumulonimbus clouds during thunderstorms. Water
builds up on the falling and rises drop to increase its size.
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Snow- water converted directly into ice.
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Droughts- Lack of water. Cloud seeding (AgI) and conservation.
12. AIR MASSES: A huge body of air that has similar temperature, humidity, and air pressure. (1 million
sq km or 10km high)
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Tropical- Warm and low pressure.
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Polar- Cold and high pressure.
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Maritime- Over oceans. Humid
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Continental – Over land. Dry
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Front: the area where two air masses of different temperatures and densities collide and do not mix.
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Cold Front: When cold air moves underneath warm air forcing the air to rise. (Could be cloudy or rainy)
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Warm Front- Warm air moves over cold air. Rain or fog or storms could last for days because warm air
moves slowly.
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Stationary Fronts- when a warm and cool air mass meets but neither has enough force to move the other.
(Stalls over an area)
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Occluded Front (complicated cold front): two cold air masses trap a warm mass in-between. Cold and
rainy.
13. PREDICTING WEATHER
METEOROLOGISTS- Someone who studies and predicts the weather.
Weather Maps:
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Symbols for fronts
Isobars- (millibars) lines that connect places where the pressure is the same
Isotherms- lines that connect places where the temperature is the same.
Flags and circles show wind speed and cloud cover.