Download Warm Spring Night

Weather and Climate
Part 1 - Introduction
CGF3M
Crescent School
Definitions
• Weather: all the atmospheric activities that
occur at a given place at a given time. The
condition of the atmosphere.
• Climate: atmospheric conditions a place has,
averaged over a long period of time. The
average of weather.
• Include: temperature, wind speed and
direction, humidity, precipitation, pressure,
cloud cover.
Weather:
•Short Term
•Small Scale
•Difficult to predict and forecast (Daily)
•Temperature, Precipitation, Humidity, Wind
direction and speed, pressure
•Meteorology
Climate:
•Long Term
•Large Scale
•Easy to predict (Seasonal)
•Climate is the averages of Temperature,
Precipitation etc.
•Climatology
07_00CO.JPG
Climatic Controls
It is obvious that not all places on earth
experience the same weather or
climate. There are a number of factors
that effect the weather or climate. They
are called ‘Climatic Controls’.
Remember Grade 9 and LOWER - Near
Water! This year we will change it up a
bit.
There are Four basic variables that influence
climate:
1. Insolation: amount of solar radiation a
place receives (amount of daylight &
angle of suns rays - Latitude)
2. Elevation: Altitude (air pressure/heat
released)
3. Proximity of water bodies: (moderates,
continental areas with large lakes)
4. Ocean currents: movement of heat from
the equator toward the poles
(temperature & precipitation)
Microclimates
• Subtle variations in temperature, humidity and
precipitation on a small scale.
– Exposure: influence of wind on temperature and
humidity
– Albedo: surfaces convert solar energy into heat
• Walk (outside) around the school one day and
you will notice surprisingly different
conditions around the area that contains the
school
• Dark Pavement
• Natural cover - grass, trees etc.
• Strong Sun
• The Shade
• Buildings acting as barriers to the sun or
wind
Exposure:
• Slopes - southern slopes receive more sun
than northern slopes
• Wind Chill - how cold the temperature feels
to people because of the wind.
• A surface that is heated by the sun will be
cooled quickly if there is a strong wind that
blows the heated air away quickly. This type of
surface will also dry faster.
Albedo:
• Dark surfaces convert more of the available
heat than light surfaces. Walk across black
pavement with bare feet on a hot summer
day, then walk on grass.
• Objects with low albedo are cooler than
objects with high albedo
Urban Heat Island:
Concrete
Tall buildings - wind tunnels
Cars, air conditioners
Subways
Pollutions - Inversions
Increased levels of Carbon Dioxide,
Carbon Monoxide, Nitrous oxide etc.
Many cities that have large parks and
ravines compensate this Urban Heat
Island effect.
The End
Go to Part 2 of the
Weather and Climate
slide shows