Lesson 102 - Atmosphere

Front 1

Define the atmosphere

Back 1

Mixture of invisible gases (molecules)

102.1.1

Front 2

Describe the extent of the atmosphere, and its density and pressure variation with height

Back 2

- depth of several hundred km, but satellite drag indicates at least 1500 km
- air becomes less dense, lighter, and less pressure with altitude
- 50% by weight below 5.5 km, 75% below 11 km

102.1.2

Front 3

Name the three properties of the atmosphere

Back 3

- mobility
- can be compressed
- can be expanded

102.1.3

Front 4

Associate compression and expansion with density, temperature, and pressure changes

Back 4

Compression:
- more dense, more friction, temp increases
Expansion:
- less dense, less friction, temp decreases

102.1.4

Front 5

Given whether air is rising or descending, determine what changes in temperature, density, and pressure are occurring

Back 5

Rising air:
- pressure decreases, air expands, density decreases, temps decrease
Descending air:
- pressure increases, air compresses, density increases, temps increase

102.1.5

Front 6

Describe the position, temperature profile, average height, and seasonal variations of the troposphere, tropopause, and stratosphere

Back 6

- layer closest to earth is troposphere
- temps decrease with height in troposphere
- tropopause is boundary line between troposphere and stratosphere
- height of tropopause average 11km, higher in summer than in winter, height 8km over poles while 18km over equator
- temps in stratosphere may remain constant or raise with height

102.1.6

Front 7

Define radiation as an energy transfer process

Back 7

Sun's energy transferred to earth, and earth's energy transferred to atmosphere and back to space in the form of waves

102.2.1

Front 8

Distinguish between absorption and reflection (with respect to heat transfer)

Back 8

- with absorption, there is transfer of wave energy and heating occurs
- with reflection, there is no transfer of wave energy and no heating

102.2.2

Front 9

Describe the effects of solar radiation on the earth's surface temperatures

Back 9

- heated by the absorption of sun's short wave radiation

102.2.3

Front 10

Describe the effects of terrestrial radiation on the earth's surface temperatures

Back 10

- cooled by earth's emission of long wave radiation, which subsequently heats the lower atmosphere

102.2.3

Front 11

Describe the roles of radiation, absorption, and reflection in heat transfer

Back 11

- not all incoming radiation absorbed by earth. Some absorbed by upper levels of atmosphere, some reflected by cloud tops, part reflected by earth's surface

102.2.4

Front 12

Describe the heat transfer process involved in daytime heating

Back 12

Short wave radiation is absorbed by earth, re-emitted as long wave radiation, which is absorbed by atmosphere

102.2.5

Front 13

Describe the heat transfer process involved in nighttime cooling

Back 13

Incoming radiation is cut off but outgoing radiation from earth continues. As source of energy decreases, less is absorbed by atmosphere, and temps start to decrease

102.2.5

Front 14

Describe the effect of cloud coverage on daytime heating

Back 14

More reflection by cloud tops, less energy absorbed by earth, cooler temps

102.2.6

Front 15

Describe the effects of cloud coverage on nighttime cooling

Back 15

Clouds absorb outgoing long wave radiation and re-radiates back towards earth, warmer temps

102.2.6

Front 16

With respect to the motion of the earth on it's axis and around the sun, define the terms rotation, revolution, and orbit

Back 16

- the earth rotates on its axis (24 hours or 1 day)
- the earth revolves around the sun (365 days or 1 year)
- the path the earth takes in its revolution around the sun is called an orbit

102.3.1

Front 17

State and explain the causes of the diurnal and seasonal temperature cycles

Back 17

Diurnal:
- day-night cycles caused by earth rotating on its axis
Seasonal:
- caused by revolution around the sun
- earth is tilted on its axis, so seasonal variations determined by changes in relationship of earth's axis to the sun

102.3.2

Front 18

State why water vapor is important as an atmospheric gas

Back 18

- only gas that can change state between solid, liquid, and gas under normal atmospheric conditions

102.4.1

Front 19

List the 2 points of importance of minute solid particles present in the atmosphere

Back 19

- condensation and crystallization nuclei
- reduces visibility

102.4.2