The Impact of Temperature on the Landscape All living things
influenced by temperature Adaptation to temperature extremes
Temperature affects human- built landscape Temperature affects
inorganic landscape components Soil and bedrock exposure Figure
4-1a & 4-1b
Slide 3
Energy, Heat, and Temperature Energy: ability to do work Forms
of energy Kinetic energy of movement Chemical, Potential, Nuclear,
etc. Temperature Heat Movement of atoms Temperature: Measurement of
heat Temperature scales Celsius Fahrenheit Kelvin Figure 4-2
Slide 4
Energy, Heat, and Temperature The Sun Primary source of energy
for Earths atmosphere Properties of Sun Average size star Nuclear
fusion Magnitude of Suns energy Energy spreads as it leaves the Sun
Travels through voids in space without loss of energy Figure
4-3
Slide 5
Energy, Heat, and Temperature Electromagnetic (EM) energy EM
spectrum Wavelength Distance between two wave crests 3 important
areas of EM spectrum Visible radiation Ultraviolet radiation Too
short to be seen by the human eye Infrared radiation Too short to
be seen by the human eye Figure 4-5 Figure 4-4
Slide 6
Insolation Incoming solar radiation Shortwave energy
Terrestrial Energy Longwave energy Earths energy Energy, Heat, and
Temperature Figure 4-16
Slide 7
Basic Heating and Cooling Processes in the Atmosphere Radiation
When objects emit EM energy AKA Heat energy emitted from a body
Warmer objects radiate more effectively Warmer objects emit at
shorter wavelengths Figure 4-6
Slide 8
Basic Heating and Cooling Processes in the Atmosphere
Absorption Body absorbs radiation Good radiator, good absorber
Reflection Objects repel electromagnetic waves Opposite of
absorption Figure 4-7
Slide 9
Basic Heating and Cooling Processes in the Atmosphere
Scattering Deflection of light waves by molecules and particles
Transmission Electromagnetic waves pass completely through a medium
Sunsets Figure 4-9
Slide 10
Basic Heating and Cooling Processes in the Atmosphere
Greenhouse effect Some atmospheric gases transmit shortwave
radiation, but not Earths longwave radiation Earth radiation held
in by atmosphere Atmospheric blanket Figures 4-11 & 4-12
Slide 11
Basic Heating and Cooling Processes in the Atmosphere
Conduction Transfer of heat energy across a medium Energy moves
from molecule to another one without changing molecular positions
AKA direct heat transfer by contact Molecules become agitated, then
vibrate & collide with cooler molecules, transferring heat
energy Figure 4-13
Slide 12
Basic Heating and Cooling Processes in the Atmosphere
Convection Heat transfer by vertical circulation in a moving
substance Vertical convection cell Warm air gains heat, expands
& rises Cool air loses heat, contracts & sinks Advection
Horizontal transfer of heat in a moving fluid AKA wind Figure
4-14
Basic Heating and Cooling Processes in the Atmosphere Adiabatic
Cooling and Warming Change in pressure & thus temperature of
rising or descending air Adiabatic cooling Air rises and expands,
molecular collisions decrease, so temperature decreases Adiabatic
warming Air sinks and compresses, collisions increase so
temperatures increase Figure 4-15
Slide 15
Basic Heating and Cooling Processes in the Atmosphere Latent
heat Heat released or absorbed during a phase change AKA hidden
heat since latent heat is not felt Evaporation: liquid water is
converted to water vapor Cooling process Condensation: water vapor
is converted to liquid water Warming process
Slide 16
The Heating of the Atmosphere Balance between shortwave
incoming solar radiation & outgoing longwave solar radiation
Albedo The higher the albedo, the more radiation the object
reflects Figure 4-16
Slide 17
The Heating of the Atmosphere: Global Energy Budget Energy in =
Energy out Figure 4-17
Slide 18
18 Earth does not distribute heat evenly through space &
time Cause of weather and climate The Heating of the Atmosphere:
Global Energy Budget
Slide 19
Variations in Heating by Latitude and Season Angle of incidence
Angle the Suns rays strike Earths surface The higher the angle, the
more intense the radiation Figure 4-18
Slide 20
Variations in Heating by Latitude and Season Atmospheric
obstructions Clouds, haze, particulates, etc. decrease insolation
Figure 4-20 Figure 3-4
Slide 21
Variations in Heating by Latitude and Season Day length The
longer the day, the more insolation is received Figure 4-19
Slide 22
Variations in Heating by Latitude and Season Latitudinal
radiation balance and the world distribution of insolation Belt of
max solar energy that moves through the tropics following the Suns
direct rays Figure 4-21
Slide 23
Land and Water Contrasts Land heats and cools more rapidly than
water due to: Specific heat Transmission Mobility Evaporative
cooling Figure 4-23
Slide 24
Land and Water Contrast Implications Oceans = more moderate
climates Hottest & coldest places on Earth are interiors of
continents N. (land) vs. S. (water) Hemisphere Figure 4-24
Slide 25
Mechanisms of Heat Transfer Need heat transfer to prevent
constant warming at tropics & cooling at poles Circulation
patterns in atmosphere and oceans transfer heat
Slide 26
Mechanisms of Heat Transfer 2 mechanisms move heat poleward in
both hemispheres, driven by latitudinal imbalance of heat
Atmospheric circulation (Ch 5) Oceanic circulation Direct
relationship between atmospheric and oceanic circulation Air
blowing over the ocean creates major surface ocean currents Heat
energy stored by oceans affects atmospheric circulation
Slide 27
Mechanisms of Heat Transfer Northern and southern variations
Near N. Hemisphere pole, landmasses lie so close that little flow
can enter the Arctic Ocean In S. Hemisphere, little land mass
allows for constant westward belt of ocean circulation called West
Wind Drift Southern Ocean (AKA the 5 th Ocean)
Slide 28
Mechanisms of Heat Transfer Temperature patterns Poleward
currents transfer warm water poleward Equatorial currents transfer
cool water equatorward Figure 4-25
Slide 29
Mechanisms of Heat Transfer Rounding out the pattern NW
portions of N. Hemisphere receive cool water from Arctic Ocean
Water pulled away from western coasts of continents = upwelling
Deep ocean circulation Global conveyor belt Tied to short-term
climate change Figure 4-26
Slide 30
Vertical Temperature Patterns Environmental lapse rate Normal
vertical temperature gradient Average lapse rate 6.5C/km or
6.5C/1000m) Temperature inversions Surface inversions Upper air
inversions Figures 4-27 & 4-28
Slide 31
31 Global temperature maps Seasonal extremes January & July
BROAD understanding of temperature patterns Isotherm: line
connecting points of equal temperature Global Temperature
Patterns
Slide 32
Primary controls on global temperature Altitude Temperature
decreases with altitude Latitude Fundamental cause of temperature
variation Temperature with latitude LandWater contrasts Continents
have higher summer & lower winter temps than oceans Ocean
currents Cool currents push isotherms equatorward; warm currents
push isotherms poleward Figure 4-29 average January temperature
Figure 4-30 average July temperature
Slide 33
Global Temperature Patterns Seasonal patterns Latitudinal shift
in isotherms from one season to another More pronounced over
continents than water and over high latitudes than low latitudes
Figure 4-31
Slide 34
Global Temperature Patterns Annual temperature range Difference
in average temperature of warmest and coldest months (usually Jan
& July) Figure 4-32
Slide 35
Global Warming and the Greenhouse Effect Climate of Earth is
becoming warmer, known as global warming Air temp increases when
atmospheric gases trap longwave radiation Human-enhanced greenhouse
effect Carbon dioxide main culprit Also methane, nitrous oxide,
CFCs Intergovermental Panel on Climate Change Figure 4-33
Slide 36
Global Warming and the Greenhouse Effect Relationship between
carbon dioxide and temperature Figure 4-35
Slide 37
Summary Temperature affects both living and nonliving aspects
of Earths landscape Energy exists in many different forms, but
cannot be created or destroyed Temperature is a measure of the
amount of kinetic energy in the molecules of a substance
Temperature is measured on three primary scales The Sun is the
primary source of energy for Earths atmosphere Electromagnetic
radiation is classified by wavelength The Sun emits three important
types of electromagnetic radiation: visible, infrared, and
ultraviolet Insolation refers to incoming solar radiation Radiation
is the process by which electromagnetic radiation is emitted by an
object Radiation can undergo several processes, including
absorption, reflection, transmission, and scattering The greenhouse
effect makes Earth able to support life
Slide 38
Summary Conduction is the transfer of heat through molecular
collision Convection is a vertical transport of heat in a fluid
Advection is the horizontal transport of heat Adiabatic cooling and
warming processes do not release or absorb heat The global
radiation budget describes the latitudinal distribution of
temperature Land surfaces heat and cool faster than water surfaces
Heat is transferred globally through atmospheric and oceanic
circulations The vertical temperature patterns in the atmosphere
help describe vertical circulations Global warming is the observed
warming of the atmosphere Temperature and carbon dioxide show a
close relationship