1. Heating Water and Land

2. Think About It: 70% of the Earth is water, therefore only 30% is land Most of that land is cloud covered So most of the incoming solar radiation strikes water As a result, the interactions between solar energy and water have a major influence on weather

3. Absorption by Water Depends on the state of the water: Snow only absorbs 10% of solar radiation Ice absorbs 50% Liquid water absorbs 93% But, the ocean’s temperatures do not vary a lot. Because of Specific Heat Capacity.

4. Specific Heat Capacity The amount of heat (energy) required to raise the temperature of 1 gram of substance by 1°C. This is a very large number for liquid water. Water: 4.18 Dry air: 1.00 Wet mud: 2.51 Brick: 0.84

5. Specific Heat Capacity The ______ the specific heat capacity, the ______ energy is needed to raise the temperature.

6. Specific Heat Capacity The higher the specific heat capacity, the more energy is needed to raise the temperature. Water is referred to as a heat sink. It absorbs excess heat, without changing state.

7. Think About It: 1 gram of water needs 21 Joules to raise its temperature by 5 degrees. 1 Joule of energy is the energy require to lift a small apple 1m straight up.

8. Think About It: The Sun emits about 3.8 x 10 26 Joules each second. But this energy reaches the entire earth (not just one part), and some is reflected!

9. Consider This: Water Balloon’s Heat Capacity Why doesn’t the water balloon burst?

10. Consider This: Back to the beach scenario. Stepping onto the sand feels very hot, but stepping into the water feels chilly. Why? Both the sand and the water are exposed to the same amount of solar radiation. The nature of the substance is why there are differences in the temperature.

11. Absorption by Land Land heats much faster than water Reasons:

12. Absorption by Land 1. Water has a large specific heat capacity If 1g of land and 1g of water receive the same amount of solar energy, the temperature of the land will increase five times more

13. Absorption by Land 2. Radiation can penetrate a larger depth in water Radiant energy reaching land will be absorbed in the top few centimeters Radiant energy reaching water will be absorbed deep into the water So the energy is spread through the water and not concentrated at the top

14. Heating Water and Land Heating soil is conduction: Transfer of heat from the top soil to the lower soil Heating water is convection: The movement of water will mix all the water to make it a uniform temperature

15. Consider This: Heating Water and Land Which warms faster? Which cools faster?

16. Heating Water and Land Water heats and cools slowly Coastal regions have a moderate climate Fewer drastic temperature changes Bodies of water make temperature changes gradual

17. Breezes Sea Breeze: During the day Air above ground is warmer than air above water Warm air rises Cooler air moves to replace it The cool air above sinks down

18. Breezes Land Breeze: During the night Land cools faster than water Air above the sea is warmer Convection current in opposite direction