1. CLIMATE
The Six Factors

2. Weather
Weather is the result of the day to day conditions of the atmosphere.
Descriptions of weather include details about temperature, precipitation, humidity, wind speed, direction, cloud cover and air pressure.
Is the result

3. Climate Climate is the pattern of weather that has occurred over
a long period of time. Example 100 years.
Global Warming - Red, orange, and brown coloring indicate areas
where temperatures measured in 2000 are warmer than the average
temperature from 1951 to 1980.

4. The Six Factors Latitude Ocean Currents Winds and Air Masses Elevation
There are six factors that affect climate.
Latitude
Ocean Currents
Winds and Air Masses
Elevation
Relief
Nearness to Water

5. Latitude The earth is tilted on an axis of 23.5 degrees.
The Earth’s axis is always pointing in the same direction (North Star).
In June the North Pole is leaning most directly toward the sun (N.H - summer),
while in December it is leaning away from the sun (N.H - winter)
Sun’s rays become less and less direct and spread out as they fall closer to the poles.
The farther a region is away from the equator, the cooler the climate will be.

6. Ocean Currents
In general, warm air and water both flow away from the equator and towards the poles.
Cold air and cold water flow away from the poles towards the equator.

7. Winds and Air Masses
Air has weight, and the pressure is created by the force of gravity.
An increase in the amount of air molecules above and around an
Object will increase the amount of pressure placed on that object.
Winds are created by the differences in pressure.
Winds move from areas of high pressure to areas of low pressure.
Air masses are large volumes of air with the same characteristics
throughout (temperature and air moisture).

8. Elevation
As air rises it expands (its pressures decreases), losing its heat.
As air rises condensation may occur(clouds). This depends on the moisture content of the air.
Rising air will cool, condense (if it has enough moisture content) and will precipitate if the clouds reach their saturation point/dew point.
As air cools it is unable to hold as much water vapour.

9. Relief Mountain ranges act as barriers to movements of air masses.
All precipitation comes from clouds, but not all clouds precipitate.
With an increase in elevation, the air temperature,
pressure and ability to hold moisture decrease.

10. Nearness to Water
As an air mass moves over a body of water it absorbs moisture.
Areas that are close to an ocean have a maritime climate
(high precipitation and mild temperatures).
Areas that are far from oceans/large bodies of water have a
continental climate (low precipitation levels, and extreme
temperatures of cold winters and hot summers)

11. Precipitation There are three types of precipitation: Relief
Convectional
Cyclonic/Frontal

12. Relief Precipitation
Air rises, cools, condenses and precipitates (if?)

13. Convectional Precipitation
The heating of the ground by the sun warms
the air above it causing it to rise (forms low pressure area. Why?)
Air cools and sinks producing a high pressure area
Air at ground level moves from high to low pressure.
This is known as?

14. Cyclonic (Frontal) Precipitation
Caused when a warm moist air mass is forced to rise by
a cool, dry air mass.
The colder more dense air forces the less dense
warm air to rise. As the air rises it …

15. The faster the warm air is forced to rise, the quicker the air cools
and the greater chance of the possibility of severe weather.
Fast-moving cold front and cumulonimbus clouds. Often
thunderstorms occur if the warm air is unstable

16. In the diagram above, was there a good opportunity
for severe weather?
The midlatitude cyclone (low pressure cell) is the most important
storm of the midlatitudes.
All precipitation comes from low pressure cells!!!! Why???

17. A warm front is produced when warm air glides up over
a cold air mass. Precipitation is moderate and occurs
within a few hundred kilometers of the surface front

18. This is because the air masses have different temperature and moisture characteristics. They are, therefore, of different densities. Like oil and water, they don’t mix easily.
Mid-latitude cyclonic storms develop along the boundaries of different air masses.

19. The following slides trace the development of a theoretical mid-latitude cyclonic storm.
The view is from above.

21. Air starts to rise as it beings to circulate around the center of the storm.

27. The storm dissipates or disappears eventually.

30. What does a mid-latitude cyclonic storm look like from the side or in cross-section?

31. B A
Note the line A to B

32. Cross-section of a mid-latitude cyclonic storm
Because the air is being forced to rise, mid-latitude storms are also called low pressure cells or systems.
Precipitation
Condensation
Cold Front
Warm Air
Air cools
Cold Air
Air rises
Warm Front A B
Cold Air

33. Is there a chance for precipitation today?
Look out the window.
Is there a chance for precipitation today?
Why or why not? .