Transcript Climate - Menihek Home Page

Climate
Weather:
• Refers to the
current,
day-to-day,
short term
conditions
of the
atmosphere.
Weather:
 Wind speed
 Wind direction
 Temperature
 Type of precipitation
 Amount of precipitation
 Cloud cover
 Humidity
 Air pressure
 Hours of sunshine.
Climate:
• Refers to the long
term trends /
patterns in the
weather for a
certain area.
• Different areas
experience different
climate.
• Monthly,
seasonal, yearly.
Do the following phrases refer to weather or climate?
• Annual precipitation of 200 mm.
• Rain forecasted for tomorrow Tuesday.
• Normal July temperature averages 22˚ C
• Temperatures this week will range between 20 &
30˚C
Do the following phrases refer to weather or climate?
• It was unusually hot this summer.
• Grand Falls-Windsor had 15 cm of snow this past
weekend.
• Vancouver has an annual frost free period of 233
days.
• Residents in Florida are preparing to take shelter
from a hurricane.
 Sun’s energy is unevenly distributed across the earth’s
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surface
This heat imbalance sets the atmosphere and the
oceans in motion
60% of the Sun’s heat energy is redistributed around
the planet by Winds
40% by Ocean currents
Places located away from large bodies of water have a
continental climate (eg.. Swift Current, Saskatchewan)
Places located near the ocean have a maritime climate
(eg.. Peggys Cove, Nova Scotia
Understand the cause of wind and how they
affect climate
 A wind is a horizontal movement of air across
a surface.
 Vertical movements are currents or updrafts
and downdrafts
 Caused by what????
 Heat versus cold!!
 Unequal heating
 Unequal heating causes pressure differences
 Cold, heavy air sinks = high pressure
 Warm, expanding air rises = low pressure
 Winds blow from high to low
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The statement is fact.
Think:
1. Air inside a balloon
2. Exhaling
3. Air powered pellet gun
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It is simply fact.
High and low pressures in the earth’s
atmosphere are responsible for wind
Wind:
 is a horizontal movement of air across a surface.
 It results from air masses of different temperatures and
humidity lying next to each other.
 The resulting pressure variation causes “wind” to blow
from high pressure areas to low pressure areas.
Prevailing Wind:
 Is regular, predictable, normal wind direction for a
given area or region.
 Caused by global convection cells.
 Named after the direction from which it comes
 Large volumes of air with
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Air Masses
North American Air Masses
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similar temperature and
moisture
Continental Arctic – comes
from Northern Canada and is
COLD and Dry
Maritime Tropical – comes
from the Caribbean and is
WARM and WET
Maritime Polar – comes from
Atlantic Ocean and is COOL
and WET
They affect climate in Atlantic
Canada because they bring to
the characteristics of that
particular air mass (See
handout # 62 and Map Page
38)
 Leading edge of an air
Front
Cold and Warm Fronts
mass
 Fronts, like air masses,
bring the characteristics
of the air mass that drives
them and also sudden
changes in weather
 Atlantic Canada is mainly
influenced by cold/dry air
masses from north that
meet warm/moist air
masses from south
 The point where the two
air masses meet is called
the front
 During summer, Canada is affected by the warm,
moist air from the Gulf of Mexico. This air mass
pushes north giving us warm summer temperatures
and precipitation.
 During winter, air masses from Canada’s north
dominate. The cold, dry air pushes south from the
arctic
 River of air moving from west to east at speeds
between 300km\h – 400km\h at altitude between
8000 and 15000 feet. ( See Figure 4.11 and 4.14 page 5455.
 May move further north in summer bringing hot and
humid conditions from the Gulf to Canada’s interior
 May move further south in winter bringing bringing
cold, dry air into Canada’s interior.