1. Heating the Atmosphere

2. Electromagnetic Waves
The sun is the ultimate source of energy that creates our weather.
You know that the sun emits light and heat as well as the ultraviolet rays that cause a sunburn.

3. Electromagnetic Waves
These forms of energy are only a part of a larger array of energy called the electromagnetic spectrum.
All radiation, whether X-rays, radio waves or infrared waves, travel through the vacuum of space at 300,000 kilometers per second.

4. Only 7% of the light energy received by the earth is visible light.

5. Electromagnetic waves are classified
by their wavelengths; the distance from the crest of one wave to the crest of the next wave.

6. Heat transfer Three mechanisms of energy transfer as heat are
—Conduction
—Convection
—Radiation
All three processes happen simultaneously in our atmosphere.
These mechanisms work to transfer energy between Earth’s surface (both land and water) and the atmosphere.

7. Heat transfer
Conduction – the movement of heat from molecule to molecule; through molecular activity
Heat flows from the higher temperature matter to the lower temperature matter
Metals are good conductors
of heat; air is a poor
conductor of heat.

8. Heat transfer
Because air is a poor conductor, conduction is important only between Earth’s surface and air directly in contact with the surface.
For our atmosphere, conduction is the least important mechanism of heat transfer.

9. Heat transfer
Convection – the movement of heat by circulation within a substance
Much of the heat transfer that occurs in the atmosphere is convection
Convection takes place in fluids where the molecules can move freely.
The atmosphere behaves like a fluid

10. Heat transfer
example of convection: a pot of boiling water

13. Heat transfer
Radiation – the release and transfer of energy in wavelengths of heat and light through space.
Solar Energy reaches the Earth from the sun by radiation
There are actually 4 laws that govern radiation….

14. 1: All objects, at any temperature, emit radiant energy
1: All objects, at any temperature, emit radiant energy. Not only hot objects like the sun, but colder objects like the Earth (including it’s polar ice caps) continuously emit energy.

16. 2. Hotter objects radiate more total energy “per unit area” than colder objects do.

17. 3. The hottest radiating bodies produce the shortest wavelengths of maximum radiation
The sun, at 6000C, radiates at .5 micrometers.

18. When radiation strikes an object, there are usually three different results.
1. Some energy is absorbed by the object. When radiant energy is absorbed, it is converted to heat and causes a temperature increase.
Like what??

19. When radiation strikes an object, there are usually three different results
2. Substances such as water and air are transparent to certain wavelengths of radiation. These substances transmit the radiant energy.
In other words – Radiation goes THROUGH the object

20. When radiation strikes an object, there are usually three different results
3. Some radiation may bounce off the object without being absorbed or transmitted.
Thus being scattered

21. This scattering is why the sky is blue…

22. … and the sunsets are often red
(what do you think is the meaning of “Red sky at night, sailors’ delight; red sky in the morning, sailors’ take warning”

23. Heat Budget of the Atmosphere

24. When it reaches the Earth, some is reflected back to space by clouds, some is absorbed by the atmosphere, and some is absorbed at the Earth's surface.
Since the Earth is much cooler than the Sun, its radiating energy is much weaker (long wavelength) infrared energy.

25. Heat energy from the earth can be trapped by clouds leading to higher temperatures as compared to nights with clear skies.
The air is not allowed to cool as much with cloudy skies.
Under partly cloudy skies, some heat is allowed to escape and some remains trapped.
Clear skies allow for the most heat to escape & cooling to take place.

27. About 50% of solar energy reaches the surface and is absorbed.
Most of THIS energy is reradiated.
The atmosphere absorbs the longer wavelengths
Larger molecules, like water vapor and CO2, absorb the energy
This energy is transformed into molecular motion – rise in temperature

28. Simplified diagram of the heating of the atmosphere

32. Albedo (Al-bee-dough)
The percent of radiation returning from a surface compared to that which strikes it When an object reflects most of the light that hits it, it looks bright and it has a high albedo. When an object absorbs most of the light that hits it, it looks dark. Dark objects have low albedos.

33. Clouds’ albedo is near 60%
Snow’s albedo is up to 95 percent
Water’s albedo is (on average) about 10%
Average albedo for earth and clouds is about 30%

42. Conditions of the Air
Temperature – amount of hotness or coldness relative to something else
Thermometer – an instrument that measures relative hotness or coldness
Dew Point temperature – The temperature at which air becomes saturated
Isotherm – a line connecting places with equal temperature on a weather map
Temperature scales:
1°C = 1.8°F or °F = 5/9 ° C

43. Celsius to Fahrenheit and Fahrenheit to Celsius
Formula
°C  x  9/ = °F
(°F  -  32)  x  5/9 = °C

44. For Example Convert 37°C to Fahrenheit. 37°C x 9/5 + 32 = 98.6°F OR5 
Convert 98.6°F to Celsius.
(98.6°F  -  32)  x  5/9 = 37°C
(98.6°F - 32) x 5 = 37°C  9

45. Conditions of the Air (cont.)
Air pressure - the downward pressure exerted by the weight of the overlying atmosphere or the “weight” of the atmosphere per unit AREA.
Barometer – an instrument used to measure air pressure
Measured in inches of
mercury in a column
Or millibars (metric
conversion)
Average air pressure
at sea level is 1013 millibars

46. What do you notice about the relationship between air pressure and volume?

47. What do you notice about the relationship between air pressure and temperature?

48. What do you notice about the relationship between volume and temperature?

50. Pressure depicted on a weather map
Isobars – lines con-necting points of equal pressure

51. Isobars on the ‘vertical’

52. Note: the density of molecules close to the surface

53. Measurement of the Atmosphere
The condition(s) of the atmosphere is measured by the radiosonde

54. A radiosonde is a small instrument package tethered to a weather balloon.
take a vertical profile of the atmosphere as the balloon ascends to altitudes up to 115,000 feet.
the data is relayed by radio transmitter to a computer at the surface

57. Launch of a weather balloon off an aircraft carrier

58. photo shows the weather balloon bursting at 99,712 feet

59. Synoptic Map
Station models – group of symbols depicting weather conditions
Isobar – line of equal pressure
a. show locations of High or Low pressures
b. close lines mean strong winds
c. lines far apart mean gentle winds

60. Station Model
how meteorologists can put a lot of information in a small area

64. Water in the atmosphere Water Vapor
Humidity – the amount of water vapor in the air
Relative humidity – the actual amount of water vapor in the air compared to the greatest amount the air can hold

65. Water in the atmosphere Water Vapor
Saturated – to be completely filled with water vapor
Psychrometer – an instrument to measure relative humidity
Hygrometer – an instrument used to measure the air’s humidity

66. Precipitation
water or ice that condenses in the air and falls to the ground as:
Rain- liquid water that falls to the ground
Snow - ice crystal flakes; water vapor in the atmosphere that froze into ice crystals and falls to the ground in the form of flakes
Sleet -partially melted grains of ice
Hail - pellets made of layers of ice and snow
Freezing rain – rain that freezes into ice as it hits the ground

67. Weather Advisories
Weather WATCH – predictions about approaching severe weather
Weather WARNING – specific severe weather conditions have been actually observed by a person or verified by a computer

69. http://www. sleepingdogstudios. com/Network/Earth%20Science/ES_17