Atmosphere
Solar radiation
Absorption: the atmosphere absorbs some of the sun’s heat. Most absorption occurs in the troposphere.
Reflection: the sun’s heat is reflected back into space by the earth. The percentage of solar radiation reflected by an object is it’s albedo
Scattering: Solar radiation is scattered in the atmosphere. It is both reflected back towards Earth and upwards into space
Heat distribution
Daily differences: The Earth rotates about it’s axis every 24hrs. The sun’s radiation is only received during the day. At night ( when a place is obscured from the sun) more heat is lost from the Earth’s surface than is replaced by incoming radiation.
Seasonal differences: Heat is unevenly distributed during the year. This is because:
- The earth revolves around the sun once every year
- The earth’s axis has a fixed tilt of about 23 1/3o
Latitude: At latitudes further away the rays fall on the earth at a more acute angle, and less radiation is received.
Solstice: The times when the sun appears furthest from the equator, and is over either of the tropics.
The global heat budget
In some locations on the earth, there is more heat received from the sun than is reflected by earth. These locations are mainly in the tropics. In contrast, in polar regions and at high altitudes, less heat is received from the sun than is reflected by earth. The excess of heat that results in the tropics is transferred to the poles and high altitudes by the two processes of Horizontal Transfers and Vertical Transfers.
Absorption: the atmosphere absorbs some of the sun’s heat. Most absorption occurs in the troposphere.
Reflection: the sun’s heat is reflected back into space by the earth. The percentage of solar radiation reflected by an object is it’s albedo
Scattering: Solar radiation is scattered in the atmosphere. It is both reflected back towards Earth and upwards into space
Heat distribution
Daily differences: The Earth rotates about it’s axis every 24hrs. The sun’s radiation is only received during the day. At night ( when a place is obscured from the sun) more heat is lost from the Earth’s surface than is replaced by incoming radiation.
Seasonal differences: Heat is unevenly distributed during the year. This is because:
- The earth revolves around the sun once every year
- The earth’s axis has a fixed tilt of about 23 1/3o
Latitude: At latitudes further away the rays fall on the earth at a more acute angle, and less radiation is received.
Solstice: The times when the sun appears furthest from the equator, and is over either of the tropics.
The global heat budget
In some locations on the earth, there is more heat received from the sun than is reflected by earth. These locations are mainly in the tropics. In contrast, in polar regions and at high altitudes, less heat is received from the sun than is reflected by earth. The excess of heat that results in the tropics is transferred to the poles and high altitudes by the two processes of Horizontal Transfers and Vertical Transfers.
Student activities
| 11g_bi_-_2_atmosphere_cloze_passage.docx |
| 11g_bi_-_2_atmosphere_diagram_fill_in.doc |
| 11g_bi_-_2_atmosphere_questions_overhead.docx |
| 11g_bi_-_2_atmosphere_structure_diagram.docx |
