Chapter 3

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Transcript Chapter 3

Chapter 3 Air Temperature

Surface and Air Temperature

Surface Temperature When solar radiation strikes the ground what happens to: • Shortwave radiation?

• Longwave radiation ?

• Sensible heat flows?

• Latent heat transfer?

• Convection?

Temperatures Close to the Ground • Temperatures on the ground usually more extreme than temperatures at standard height (4 ft.) • Soil, surface, and air temperatures vary throughout the day Visualizing Physical Geography Copyright © 2008 John Wiley and Sons Publishers Inc.

Surface and Air Temperature

Environmental Contrasts: Urban and Rural Temperatures Surface materials influence temperature strongly Why?

Transpiration?

Evapotranspiration?

The Urban Heat Island City centers tend to be several degrees warmer than surrounding suburbs and countryside.

Why?

Albedo evapotranspiration

High-Mountain Environments • Reduced air pressure  reduced oxygen to lungs • Fewer air molecules  sun’s rays stronger • Less CO 2 and water vapor  reduced greenhouse effect What do these graphs show?

Temperature Inversion

: reversal of normal temperature pattern so that air temperature increases with altitude Occurs when cold marine air slips under warm air.

Daily and Annual Cycles of Air Temperature

• Insolation varies by season • Net radiation varies daily • Positive after sunrise • Peaks at noon • Decreases to negative by sunset • Air temperature varies daily When is lowest temp? When max? Why

Land and Water Contrasts Temperature Ranges for Maritime and Inland?

Daily and Annual Cycles of Air Temperature

Annual Net Radiation and Temperature Cycles Annual cycle of daily insolation affects  net radiation, which affects  monthly mean air temperature Review sheet #16

Isotherm?

Air temperature maps- high, low temp, gradients

Temperature gradient

: rate of temperature change along a selected line or direction

World Patterns of Air Temperature

Factors Controlling Air Temperature Patterns Three main factors explaining world isotherm patterns: 1. Latitude affects annual insolation, temperatures, and seasonal temperature variation 2. Maritime-continental contrast 3. Elevation

Patterns to note: •Large land masses in Arctic and subarctic zones are extremely cold •Ice and snow reflect insolation •Temperatures decrease from equator to poles • Highlands are colder than surrounding lowlands.

• Temperatures in equatorial regions?

• Continents heat/cool faster than oceans

Temperature Structure of the Atmosphere

Aerosols

: tiny particles present in the atmosphere

Temperature Structure of the Atmosphere

Stratosphere and Upper Layers

Stratosphere

: What is happening to temperature?