World Climate Patterns

1
Unit 2

• World Climate Patterns An Introduction

2
Distinguish between the terms weather climate.
P. 54

• Weather the state of the atmosphere at any one
  place or time. (short term)
• Climate the average weather conditions of a
  region over the LONG term. (Season, Month
  Annually)
• Both refer to temperature, rain fall, humidity
  etc.

3
PracticeDo the following phrases refer to
weather or climate?

1. Annual precipitation of 200 mm.
2. Rain forecasted for tomorrow.
3. Normal July temperature averages 22 oC.
4. Temperatures this week will range between 20 30
   oC.
5. It was unusually hot this summer.
6. Vancouver has an annual frost free period of 233
   days.
7. The greatest annual precipitation 11, 680 mm
   falls on Mt. Waialeaie in Hawaii.
8. Residents in Florida are preparing to take
   shelter from a hurricane.

Climate Weather Climate Weather Climate Climate
Climate Weather
4
In describing todays weather 9 features are
often used!!

• Temperature
• Amount of precipitation
• Type of precipitation
• Atmospheric pressure
• Wind direction
• Wind speed
• Cloud cover
• Hours of sunshine
• Humidity

5
Explain why only about ½ of the sunlight
directed at earth actually reaches the earth.
6
49 of suns radiation actually reaches the
earths surface

• 6 is scattered in the atmosphere
• 24 is reflected by clouds
• 4 is reflected by the earths surface.
• 17 is absorbed by Green House gases dust

7

• While the 4 that reflects from the earths
  surface is small it does vary with location
  with time.
• How/Why do you think it varies?
• Winter vs. Summer?
• Poles Vs. equator?
• Land vs. ocean?
• HINT Precipitation (Snow water), reflection vs
  absorption, dust, cloud cover, angle of sun,

8
Lack of cloud cover Day AND Night the
effect

• DAY No clouds higher day temperatures
• NO clouds to deflect / block heat from reaching
  the surface.
• NIGHT NO cloud cover cold nightly
  temperatures. (heat escapes, nothing to TRAP it.)
• Ex. Day 24o C, Night 15o C

9
Clear Day AND clouds over BEFORE nightthe effect

• DAY No clouds higher day temperatures
• NO clouds to deflect / block heat from reaching
  the surface.
• cloud cover PRIOR to night warmer and muggy
  nights.
• heat being TRAPPED during the nightlike a
  blanket AND precipitation in the clouds.
• Ex. Day 24o C, Night 21o C

10
Cloudy Day AND NO clouds at Night the
effect

• DAY Cloud cover lower daily temperatures
• Clouds deflect/block out sun heat.
• NIGHT NO cloud cover even COLDER nightly
  temperatures.
• Already cooler temperatures become even lower.
• Ex. Day 15o C, Night 9o C

11
Cloudy Day AND cloudy Nightthe effect

• Day Cloud cover lower daily temperatures
• Clouds deflects/blocks out heat
• Night Cloud cover relatively constant
  temperatures in the night.
• Clouds traps current air temperatures and keeps
  them relatively constant.
• Ex. Day 15o C, Night 12o C

12
Explain how cloud cover influences the range of
temperature from day to night.

• Clear day / Clear Night largest temp range
  (24159)
• Clear day, cloudy night small/low temp range
  (24-213)
• Cloudy day, clear night moderate range (15-96)
• Cloudy day / cloudy night small temp
  range(15-123)