CLIMATE CHANGEChapter 7

WEATHER vs CLIMATE• Weather describes a set of environmental conditions encountered

from day to day (short-term).

• The two main factors are temperature and precipitation

• Climate is the prevailing weather conditions at a locality averaged over many years (long-term).

• The climate of an area is affected by 5 main factors:– latitude (angle measured north or south of equator)– altitude/elevation (height above the earth’s surface)– Air masses that flow over the area– Area’s nearness to large bodies of water– Mountain ranges also effect climate

CLIMATOGRAPH

• Plots average monthly temperature and precipitation over several years

Constructing a Climatograph (Orange box on page 270)

• What every climatograph must include!• 1) All titles, underlined with a ruler• - Main title: include location and timeframe• - Axis titles: include name and units • 2) Avg precip = bar graph• - #'s on left y-axis• 3) Avg temp = line graph• - #'s on right y-axis• ** does not always start with 0 **• 4) Legend

Latitude & Altitude

The Sun Heats the Earth(Latitude)

HOTTEST @ EQUATOR

Seasons

Mountains are Physical Barriers

BIOMES• Climate determines the distribution of organisms.

4 Spheres of Earth

• Atmosphere (air) • Hydrosphere (water)• Lithosphere (stone)• Biosphere (life)

• All four spheres interact.

• For example, soil will have water (hydrosphere), mineral material (lithosphere), air pockets (atmosphere) and earthworms (biosphere).

Earth’s Atmosphere

• Composition of AIR– 78% Nitrogen gas– 21% Oxygen gas– 1% Other gases (including carbon dioxide,

0.03%)

The Greenhouse Effect

Earth’s Natural Greenhouse Effect

Compared to Our Neighbours

Albedo(Reflectivity)

• HOMEWORK

• Page 273 #1 - 5, 9, 16

Thermal Energy (Heat) Transfer

• This is the movement of thermal energy from an area of HIGH TEMPERATURE to an area of LOW TEMPERATURE

• There are 3 types of transfer:

1) Radiation

2) Conduction

3) Convection

Radiation

• the emission of energy as electromagnetic waves• When radiant energy (THE SUN) encounters

particles of matter, it may be reflected or absorbed. If absorbed, the energy increases the movement of the particles (increasing kinetic energy).

• When kinetic energy increases, the temperature increases. The more sunlight that hits the ground the hotter it will become.

Conduction

Convection

• Homework:

• READ 7.2

• ANSWER:

• Pg 278 #1-3

• Pg 289 #1, 4-6,9,10

Ocean Surface Currents

Surface Wind Patterns

The Coriolis EffectEffect of the Earth’s Spin

• The deflection of any free moving object (air masses and water) from a straight-line path by the rotation of the Earth

• http://www.youtube.com/watch?v=mcPs_OdQOYU

Coriolis Effect in Each Hemisphere

• Winds in the Northern Hemisphere deflect to the right.• Winds in the Southern Hemisphere deflect to the left.• Remember that wind pushes the ocean surface.

Convection in Earth’s Atmosphere• At the equator, where the insolation is greatest, hot, less dense air

rises and moves polewards. As it reaches higher latitudes, it cools, becomes more dense, sinks and travels back to the equator along the earth’s surface.

Atmospheric Circulation

Great Ocean Conveyor Belt(Deep Thermohaline Current)

• Combination of convection and variations in salinity. Salt water is more dense than fresh water, so it sinks.

Hometime Fun!

Read pages:279-285Page 289 # 7, 11-13Page 292 #16-20, 24, 25, 28