1. Heat Capacity
The heat capacity of a substance is a measure of how well the substance stores heat.

2. Whenever we supply heat to a material, it will necessarily cause an increase in the materials’ temperature

3. The heat capacity is defined as the amount of heat required per unit increase in temperature
(i.e. it depends on the substance and the mass)

4. materials with large heat capacities, like water, hold heat well
Thus,
materials with large heat capacities, like water, hold heat well
-they are heat “hogs” and want to
keep the heat
-they do not give up heat easily
-they absorb heat slower (they resist
a change in temperature)

5. materials with small heat capacities, like copper, don't hold heat well
- they are “weak” and will give up heat easily
- their temperature will rise quickly when exposed to heat

6. Radiational cooling 
The cooling of the Earth's surface and the air near the surface, occurring chiefly at night.

7. Because infrared radiation is absorbed by water vapor, cloudless nights usually allow for greater radiational cooling than overcast nights.

8. Radiational cooling occurs in all regions of the Earth and is important in maintaining the Earth's energy balance.

9. So, what does it mean?
air over surfaces with high heat capacity will warm slower than air over surfaces with low heat capacity.
high heat capacity= heat hog, wants to keep
what it has, resists change
low heat capacity = weaker in holding heat,
will give it up easily to something with a
greater heat capacity (stronger)

10. Heat Capacity of Substances
HEAT CAPACITY (cal/gramoC)
Air, dry at sea level
0.24
Sand, quartz
0.19
Water
1.00
Soil
0.60
Asphalt
0.22
Bone
0.11
Ice
0.50
Granite
Wood
0.14
Clay soil type
0.33

11. Based on the information given:
Why does the desert get so cold at night?