Transcript 675LatAmClimate(comp..

Latin America
Climate – Environmental
Geography
GCU 122 – World Regional Geography
Jason Donoghue
Chandler-Gilbert Community College
Controls of Climate
Latin America
• The different climatic regions of Latin
America are influenced by the following
factors:
– Global atmospheric circulation
• Positions of the Intertropical Convergence Zone,
and the sub-tropical high pressure zones.
• Location of major global wind belts
– Geological configurations
• Highlands of the Andes mountains
• Altitudinal Zonation
Global Atmospheric Circulation
• Rising air at the
equator allows for an
abundance of
precipitation year
round.
• The sub-tropical high
is were you will find
some of the drier
savannah and desert
regions.
Effects of Pressure Zones
• Sub-Tropical Highs
• Equatorial Low
Global Wind Belts
• Wind patterns
coupled with the
physical landscape
have a significant
impact on climate.
– Two prime examples
• Atacama Desert
• Gulf coast of “Middle
America”
Orographic Effect
Atacama Desert
• Prevailing winds from the east are
forced up by the Andes
Mountains, and descends on the
leeward side.
– Creates a dry high pressure zone.
Orographic Effect
Caribbean Coast – Middle America
• Prevailing winds from the
east, again and are forced
up by the highlands,
creating areas of low
pressure
– This leads to precipitation, and
the lush rain forests located
here.
Vertical Climate Zones
• Middle and South America also experience
areas where you may find several different
climates in one area.
– This is because of the highland regions, and
the fact that as you rise in altitude the
temperature cools.
• For every 1000 feet up you lose 5.5º
Altitudinal Zonation
Middle & South America’s Vertical Climate Zones
Altitudinal Zonation
Middle & South America’s Vertical Climate Zones
TIERRA CALIENTE
(Hot Land)
Bananas, Cocoa, Sugar, Rice
2500’
Sea
Level
750 m
Sea
Level
Altitudinal Zonation
TIERRA TEMPLADA
(Temperate Land)
Coffee, Rice, Corn, Sugar
6,000’
2000’
Sea
Level
1800 m
600 m
Sea
Level
Altitudinal Zonation
TIERRA FRIA
(Cold Land)
Corn, Wheat, Potato
12,000’
6,000’
2000’
Sea
Level
3,600 m
2,000 m
600 m
Sea
Level
Altitudinal Zonation
TIERRA HELADA
(Frost Land)
12,000’
6,000’
2000’
Sea
Level
3,600 m
2,000 m
600 m
Sea
Level
Climate Zones
• Tropical Rainforest
• Tropical or subtropical
desert
• Tropical Savanna and
Grasslands.
• Mid-latitude Grasslands
• Mediterranean Climate
• Marine West Coast
Climate
• Highland Climates
Tropical Rain Forest
• The equatorial zones of
high temperatures, and
rainfall provide conditions
for the rapid growth of
vegetation in the form of
rain forests of the
Amazon and Middle
America.
– The Amazon basin ranges
from 60 to 80 inches of rain
per year.
Tropical or Subtropical Desert
• Warm and dry all year long.
– Partially due to the subtropical
high pressure zones located in
these regions.
• Air becomes warmer and
drier over the tropics and
sinks.
– For the Atacama Desert it lies
in the rainshadow of the
Andes Mountains
• Additionally the cold ocean
currents that flow north along
the west coast of South
America do not allow the
winds to absorb much
moisture.
Tropical Savanna and Grasslands
• These areas are typically
warm and have some sort
of seasonal precipitation.
– The seasonal precipitation
depends on shifts in global
wind patterns and pressure
belts that shift to the north
in the June-August season
and to the south in the
November-February
period.
• Caracas, Venezuela
• Brasilia, Brazil – Wet
Season – Nov. to Feb.
– Moto Grasso Plateau
• Caracas, Venezuela – Wet
Season – Jun. to Oct.
– Llanos
• Llanos
Mid-Latitude Grasslands
• This climate zone is
characterized by
cooler temperatures,
and low or seasonal
amounts of
precipitation.
– Buenos Aries,
Argentina
– Patagonia and the
Pampas in Argentina
Mediterranean
• Moderate temperatures
with dry summers and
wet winters.
• Confined to a small
section of southern Chile.
– This is due in part to the
ocean currents, wind
patterns and the location of
the Andes Mountains.
• Wind patterns shifting
north in June results in a
distinct wet season here,
and a distinct dry season
in winter.
Marine West Coast
• Cooler and wet all year
long.
• Much like the
Mediterranean Climate
this zone is found in a
small area of southern
Chile, and is controlled by
the same factors.
– The westerlies bring heavy
rains to the coast here,
partially due to the
orographic effect caused
by the Andes Mountains.
Highland
• Typically cooler
temperatures, but this
is where altitudinal
zonation comes into
play.
– Many different climate
types can actually be
contained within this
zone.
Natural Hazards and
Environmental Concerns
• Tectonic Activity
– Volcanoes and Earthquakes
• Caribbean Wind Patterns
– Abundance of Hurricanes
• El Nino
– Changes in Wind/Water flow that has global
implications
• Deforestation of the Amazon
– Destruction of the “lungs” of the planet
Tectonic Plates
Earthquakes and Volcanoes
Mexico City - 1985
• In 1985 a major
earthquake struck
Mexico City.
– Killed as many as
10,000 people
– Devastated downtown
buildings
– City sits on an old lake
bed with sediments
that act similar to
liquids during an
earthquake
Caribbean Wind Patterns
• Tradewinds out of the east in this part of the
world cause the eastern coasts of Mexico, and
countries in Middle America vulnerable to
hurricanes.
Honduras - 1998
• Hurricane Mitch slammed
in to Honduras and
surrounding nations in
late October of 1998.
– Dumped a year’s worth of
rain in 48 hours.
– Flash floods and mudslides
deforested slopes
– Left nearly 10,000 dead,
and almost 20,000 missing.
• Devastated the Honduran
capital of Tegucigalpa.
El Nino
• Normal Cycle
• El Nino is a significant reason
why climate in Latin America is
usually variable.
– During an El Nino cycle
typically cool waters off the
coast of Peru begin to warm.
– This is because there is a shift
in the weather patterns that
characterize the south Pacific.
• Usually we see wind patterns
that force the warmer water
towards Indonesia and during
an El Nino year, this wind
slackens, or shifts entirely,
allowing the warm waters to
flow back across the Pacific
ultimately off the coast of
Peru.
• El Nino Cycle
Effects of El Nino
• Brings warmer and wetter
winds to the coasts of
Peru and Ecuador.
– With this we see flooding
and mudslides.
• Global Effects:
– Droughts in northeast
Brazil
– Floods in southern Brazil
and northern Mexico
– Fewer hurricanes due to
wind pattern changes.
– Droughts and fires in
Indonesia, South Africa,
and Australia
Deforestation of the Amazon
• In the 1970’s the Brazilian
government began to focus on
the development of the
Amazon.
– Along with this came the
beginning of large scale
deforestation of the rain forest.
• Networks of roads were built.
• Thousands of fires are set
each year to clear large
sections of forest
• The rate of deforestation vary
region by region based on
how they are being cleared,
and used.
– General agreement is that
15 percent of the Amazon
basin has been cleared and
the current rate is 50,000 sq
miles a year.