8.8 Energy Transfer within the Climate System Earth is unevenly heated by the Sun because The Sun’s radiation reaches Earth’s surface with different intensities at different latitudes. Water and land absorb energy at different rates. The atmosphere and hydrosphere can absorb and store thermal energy, so they act as heat sinks. The climate system transports thermal energy from areas that have more energy to areas that have less energy. Most of this thermal energy circulation takes place in the atmosphere and hydrosphere. heat sinks

8.8 Energy Transfer within the Climate System Energy Transfer in the Atmosphere The movement of warm and cold air creates a circular current called a convection current. Convection currents are one of the main ways that energy is transported in the atmosphere. convection current Earth has permanent bands of high and low pressure, so there are prevailing winds that blow in the same direction almost all of the time. Prevailing winds move warm air and warm water from the equator towards the poles. Figure 4 Bands of high and low pressure around the globe create air currents (winds) that blow from areas of high pressure to areas of low pressure. Winds are named based on the direction they originate from.

8.8 Energy Transfer within the Climate System Energy Transfer in the Oceans Cold, dense ocean water at the poles sinks to the ocean floor. Warmer surface water from the equator then flows to the poles to take its place. This process is called the thermohaline circulation of the oceans. Ocean currents around the globe slowly move water (and the thermal energy it carries) from the equator to the poles. thermohaline circulation Figure 5 Red lines show warm ocean currents and blue lines show cold ones. Warm water currents travel on the surface, but cold water currents travel deep down in the ocean.