Physical Geography 101
Temperature Structure of the Atmosphere


Temperature and Elevation

Lower atmosphere: increased elevation = decreased temperature.
Temperature decreases at constant rate:
Lapse Rate 6.4°C/1000 meters

Structure of the Atmosphere

Troposphere

0-14 km
Lower atmosphere
- Contains most of the weather that affects us
- significant amounts of water
- abundant aerosols (fine liguid and solid particles)

Tropopause

approx. 14 km (varies in elevation with seasons)
Level at which temperature stops decresing with altitude and begins increasing

Stratosphere

14 - 50 km
High altitude air mass - low water and dust content
Ozone layer is found in this layer

Mesosphere  50-85 km
Thermosphere  85-500 km
Exosphere  >500 km

Air Density

Increased elevation results in decreased air density

Temperature Inversion

Temperature increases with increasing elevation.
Occurs when:
- ground loses radiation to the air
- ground is colder than the air

Annual Temperature Cycle

Temperatures vary annually - based on variations amount of insolation (axial tilt).

Land vs. Water Temperatures

Coastal areas:
- Generally cooler than inland areas
- Lower annual and daily variations
Four thermal properties of water and land explain why.

1) Penetration

2) Specific Heat

3) Convection

4) Evaporation

Inland vs. Coastal Temperatures

Coastal areas: Less variation in daily and annual temperature.
Inland areas: More variation in daily and annual temperature.