Heat Energy Transfer Mechanisms

Study Notes

Heat energy can be transferred through three mechanisms: radiation, conduction, and convection.
Radiation is the release of infrared radiation by a substance at a higher temperature than its surroundings and is the only mechanism that works in a vacuum.
Conduction is the transfer of kinetic energy between particles in direct contact and is most effective in solids.
Convection is the movement of particles from one location to another, where cooler, denser material sinks relative to warmer, less dense material.

Energy arrives from the Sun in the form of radiation (both visible and infrared).
Not all of this energy is absorbed, with some reflected (albedo) depending on the surface (ice and snow reflect more than land or ocean).
Different surfaces have different temperature responses to the same heat energy input (e.g., water has a high heat capacity, which means it takes more energy to change its temperature).

The uneven heating of the Earth's surface results in the transfer of heat energy from the equatorial region to the poles through convection in the atmosphere and hydrosphere.
Convection in the atmosphere leads to the formation of different biomes (e.g., rainforest and desert).

The Coriolis Effect forces surface air moving toward the Equator from east to west, resulting in trade winds.
Similar convection cells between 30°N and 60°N and 30°S and 60°S latitudes result in prevailing westerly winds.

The patterns of ocean currents are complicated by the position of the continents.

Global warming affects the climate by changing heat energy transfer.
Examples of effects include:
- Increased evaporation from oceans, leading to increased precipitation of snow over the Northern Hemisphere.
- Increased melting of glaciers and Arctic ice, potentially reversing the North Atlantic Drift that keeps Europe temperate.