What is a balanced heat budget?
When an equal amount of heat enters and leaves the atmosphere
Why does any object that is receiving heat from another object change temperature?
- The object receiving heat does not have a balanced heat budget
- More heat is being directed toward the object than what is leaving the object
- Temp will increase as long as the amount of heat that it is receiving is greater than the amount of heat it is losing as infrared radiation
How much solar energy is reflected when it strikes Earth?
30%
How much solar energy is absorbed by the atmosphere when it strikes Earth?
20%
How much solar energy is absorbed by Earth’s surface (land+oceans) when it strikes Earth? (what happens?)
50%
20% absorbed by surface + re-emitted as infrared radiation back to space
30% conducted to the lowermost atmosphere, convected to high elevations, radiated to space as infrared
What is insolation?
The amount of solar radiation received at a location
What is the albedo of the Earth and how does it compare to the albedo of other planets?
- Earth’s albedo = 35%
- Gas giants- high- clouds
- Mercury- low (6%)- no atmosphere
- Venus- high (72%)- clouds
- Mars- low (16%)- rock/sand/dust + ice caps
- Moon- low (7%)- basalt (dark rock), appears bright because we are close to it
What on the Earth has a very high or low albedo?
Ice + clouds: 75-95 Grasslands- 20 Deserts: 30 Rock: 5-30 Forest: 10 Ocean: 2-4 (higher when sun is low in sky)
How is electromagnetic radiation classified? (lowest to highest frequency)
AM radio, Shortwave radio, Television FM radio, Microwaves, radar, millimeter waves, telemetry, infrared, visible light, ultraviolet, X-rays, Gamma rays.
What is the warmest month of the year in the Northern hemisphere? Why is this not the time it is receiving the most direct solar radiation?
- Warmest: July
- Most radiation: June
- Days becoming shorter
- Sun lower
- The amount of incoming solar energy is still more than the amount of heat we are losing as infrared radiation
When is the coldest month of the year? Why is this not the same time we receive the least direct solar radiation?
- Coldest: January
- Least radiation: December
- Days becoming longer
- Sun higher
- The amount of incoming solar energy is still less than the amount of heat we are losing as infrared radiation
When is the warmest time of day? Why?
- Warmest: mid afternoon
- Most radiation: solar noon
- Sun is sinking and we are receiving less solar energy after noon
- The amount of incoming solar energy is still more than the amount of heat we are losing as infrared radiation so temp still rising
What heats up faster - land or ocean? How does this affect our climate?
- Land heats up faster- water has a higher “specific heat” than rock or soil
- Takes more energy to raise the temperature of water than the temperature of rock by 1 degree
- Land does not conduct heat too well, so energy is concentrated in the top few inches of land
- In oceans, heat is conducted well- convection + waves, spreads out energy
What does a warm object emit more of than a cooler object?
- Warmer objects emit more infrared radiation
- All things emit infrared radiation if their temperature is above absolute zero
- The higher the temperature, the more infrared radiation an object emits
What is a temperature inversion?
When temperature increases with increasing elevation, instead of decreasing
Why is a temperature inversion called that?
It is opposite of what usually happens
How does temperature inversion form?
- After cold clear night, ground lost heat/thermal energy in the form of infrared radiation
- Cold ground chills air in contact with it to a temp lower than air farther up
- Layer of warmer air sits above the colder air, colder air has higher density + doesn’t rise so it stays there
- If air chilled to dew point temp, water will condense to form fog (or freezing fog)
What brings an end to the inversion?
- Usually ends when the sun comes out in the morning, but can last several days
- Sun can’t always burn off fog
Describe the conditions by which it may become hazardous to human health
- If pollution gets trapped/concentrated below the warm air, air may be hazardous to breathe
- This may affect young children and elderly
What is usually colder during the winter: a cloudy or clear night? Why?
- Clear nights become colder, because the heat has more of a chance to escape from the ground
- Clouds prevent the heat from leaving. Clouds absorb infrared radiation and radiate heat back
How do greenhouse gases warm the atmosphere? What would the temperature of the Earth be like if there were no greenhouse gases?
- Greenhouse gases keep in heat, so it does not escape the atmosphere
- If there were no greenhouse gases, the Earth would be a lot colder since it would not be able to keep in heat as well
How does a sea breeze form?
- Forms at mid-afternoon when air rising off the hot land is replaced by cooler air from the sea
- Clouds may form, and cold air sinks over the ocean
When do temperatures begin to fall?
- Late July:
- The amount of incoming solar radiation and the amount of outgoing heat (infrared) are equal
- After late July:
- The amount of incoming solar energy is less than the amount of outgoing infrared and temp begins to fall
When do temperatures begin to rise?
- Late January:
- The amount of incoming solar radiation and the amount of outgoing heat (infrared) are equal
- After late January:
- The amount of incoming solar energy is greater than the amount of outgoing infrared and temp begins to rise
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Rocks and Minerals83
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Earthquakes34
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Tectonic Plates39
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Interior of the Earth46
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Air Pressure and Wind43
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Moisture in the Atmosphere64
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Heat31
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Density10
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Earth's Atmosphere41
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The Moon47
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Earth Motions, Latitude / Longitude, and the Seasons51
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Space History Notes63
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Chapter 30: Stars87
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Solar System50
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Origin of the Solar System16
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The Age of the Earth + Scientific Method8
