13.3 Interactions of Solar Energy with Land and Air
Pages 435 – 446 (omit investigations)
- Low specific heat capacity explains why sand’s temperature will increase five times faster than water.
- Water’s transparency allows heat to be distributed more evenly (because the sun’s energy reaches the deeper water).
- Soil is not transparent, so its temperature only gets warm at the surface from the sun’s energy.
- Conduction warms the air near the ground: Air molecules that are in contact with the ground’s surface receive energy (as collisions due to vibration). (Happens in a very thin layer at the surface)
- Convection warms the air at higher altitudes because the warm air is less dense (molecules are farther apart in warm air) and rises.
- ** Should be last question!**Without carbon dioxide and water vapour in the atmosphere temperatures would be too cold for us and many living things.
- The air above dry land is warmer than the air over water during the day because…the land gives off more heat (soil and rock become very warm at the surface).
- Day: Warmer air rises above land during the day, replaced by cool air from over water. (ONSHORE Breeze)
Night: Land cools very quickly (low specific heat capacity) while water temperature doesn’t drop as much. Warmer air rising over the ocean is replaced by cooler air from land. (OFFSHORE Breeze)
- Complete the table (on looseleaf) describing each of the four layers of the atmosphere:
Layer / Altitude / TemperatureRange / Description
Troposphere / 0 – 10 km / Decreasing to -57ºC / All weather occurs here
Stratosphere / 10 – 50 km / Increases to about -2ºC / Ozone layer is found here. Increasing temperature is due to ozone absorbing UV.
Mesosphere / 50 – 90km / Decreasing to -100 ºC / Meteors mainly burn up here
Thermosphere / 90km + / Increases to more than 600 ºC / High temperatures but not much heat transfer (few molecules)
Aurora occur here (Northern Lights)
- Atmospheric pressure is caused by the amount of air molecules above us. Gravity pulls on the molecules (downward) which creates the pressure.
- Standard atmospheric pressure is 101 300 Pascals (101.3 kPa)
- Atmospheric pressure decreases as you go up in altitude because there are fewer molecules above you being affected by gravity.
- Local atmospheric pressures are slightly different from standard atmospheric pressure because warming or cooling the air changes pressure.
- Oxygen and ozone absorb UV, protecting cells from damage that causes cancer.
- Greenhouse gases (water, carbon dioxide, methane, nitrous oxide) prevent the Earth from quickly losing most heat to space as infrared radiation. ***Water is most important.