GEO 101: PHYSICAL GEOGRAPHY
Chapter 10: Global Climate Systems
Why does the climate differ from one place to another?
What controls the global climate?
What typical climate patterns do we have across the globe?
Do you know what a Tropical Savanna climate means?
What controls the long term climate change, e.g., global
warming?
Topics
Earth’s Climate System and Its Classification
Tropical Climates
Mesothermal Climates
Microthermal Climates
Polar Climates
Dry Arid and Semiarid Climates
Global Climate Change
Global Climate Systems
Earth’s Climate System and Its Classification
•
Climate is weather over time
•
Climatology is the study of climate
•
Climatic regions are areas with similar weather statistics
Global Climate Systems
Earth’s Climate System and Its Classification
Climate components:
•
Insolation
•
Temperature
•
Pressure
•
Air Masses
•
Precipitation
• Internal and external
processes
Figure 10.1
Global Climate Systems
Climate components:
•
Insolation : energy input for the climate system;
varies widely by latitude (Ch.2)
•
Temperature: controlled by latitude, altitude,
Land-water heating, cloud cover (Ch.5)
Distribution of Insolation
Global Climate Systems
Climate components:
•
Insolation : energy input for the climate system;
varies widely by latitude (Ch.2)
•
Temperature: controlled by latitude, altitude,
Land-water heating, cloud cover (Ch.5)
Global Climate Systems
Climate components:
•
Pressure: temp variations, global wind (Ch.6)
•
Air Masses: location, oceanic and continental
•
Precipitation: hydrologic cycle transfers
moisture with latent heat energy
to climate system
General Atmospheric Circulation and Wind patterns
Figure 6.13
Global Climate Systems
Climate components:
•
Pressure: temp variations, global wind (Ch.6)
•
Air Masses: location, oceanic and continental
•
Precipitation: hydrologic cycle transfers
moisture with latent heat energy
to climate system
Global Climate Systems
Classification of Climatic Regions
‰ There are a lot of classifications available in the
literature
‰ Empirical classification:
- based on statistical data, e.g., temperature and precipitation
‰ Genetic classification:
- based on causative factors, e.g., the interaction of air masses
Global Climate Systems
Classification of Climatic Regions
‰ Chapter 10: features both genetic and empirical
factors
‰ We focus on temperature and precipitation
measurements, and
‰ For the desert areas, moisture efficiency and
temperature
World Climate Classification
Figure 10.5
Generalized Climate Regions
Figure 10.4
Tropical Climates
z
Tropical Monsoon Climates
z
z
z
ITCZ migrates to affect these areas 6 to 12 months
A dry season that lasts for one or more months
Along coastal areas within the tropical rain forest climate
Tropical Climates
Tropical Climates
z
Tropical Rain Forest Climates
z Constantly
moist and warm (rainy all the year)
z Precipitation follows the migration of ITCZ
z Annual temperature range is only 2°C
Tropical Rain Forest
Figure 10.7
Tropical Monsoon
Figure 10.8
Tropical Climates
z
Tropical Savanna Climates
z Poleward
of the tropical rain forest climates
z ITCZ reaches these areas 6 months or less
z Summers are wet than winters
z Temperatures vary more than rain forest areas
Tropical Savanna
Figure 10.9
Classification of Climatic Regions
z Microthermal Climates (mid and high latitudes, cold winters)
z Humid continental (hot to warm summers)
z Subarctic (cool summers to very cold winters)
z Polar Climates (high latitudes and polar regions)
z Tundra (high latitude or high altitude)
z Ice caps and ice sheets (perpetually frozen)
z Polar marine
Classification of Climatic Regions
z Highland Climates (highlands at same latitudes)
z Desert (permanent moisture deficits)
z Arid deserts (tropical and midlatitudes)
z Semiarid steppes (tropical midlatitudes)
Mesothermal Climates
Humid Subtropical Hot-Summer Climates
Maritime tropical and continental polar air mass interacts
to generate midlatitude cyclones and precipitation
Hot and wet summer but dry winter
Marine West Coast Climates
Maritime polar air masses – cool, moist, unstable –
dominate
Weather is quite unpredictable
Rainy and foggy
Mediterranean Dry-Summer Climates
Dry summer but wet winter
Continental dry air masses block the maritime air masses
in the summer
Mesothermal Climates
GEO 101: PHYSICAL GEOGRAPHY
Chapter 10: Global Climate Systems
Topics
• Microthermal Climates
• Polar Climates
• Dry Arid and Semiarid Climates
• Global Climate Change
Generalized Climate Regions
Figure 10.4
Classification of Climatic Regions
Microthermal Climates (mid and high latitudes, cold winters)
Humid continental (hot to warm summers)
Subarctic (cool summers to very cold winters)
Microthermal Climates
1. Humid Continental Hot-Summer
Climates
Humid and hot in summer
Dry and cold in winter
NY and Dalian in China
Microthermal Climates
Microthermal Climates
2. Humid Continental Mild-Summer Climates
Humid but not hot summer and dry winter
Lower temperature, precipitation from snow
E.g., Duluth, Minnesota
Microthermal Climates
Microthermal Climates
3. Subarctic Climates
Greater seasonal changes and annual T changes
Dry and very cold winter
E.g., Alaska, Canada, Siberia in Russia
Microthermal Climates
Classification of Climatic Regions
Polar Climates (high latitudes and polar regions)
Tundra (high latitude or high altitude)
Ice caps and ice sheets (perpetually frozen)
Polar marine
Polar and Highland Climates
1. Tundra Climate
Continuous snow cover for 8-10 months
Warmest months can be above 0°C but never
exceeds 10°C
Mainly in northern hemisphere, except for high mountains
Polar and Highland Climates
2. Ice Cap and Ice Sheet Climates
Most of the Antarctic and central greenland
3. Polar Marine Climate
Moderate than ice sheet climates, T > -7°C
Cold than the Tundra climates
Polar and Highland Climates
Classification of Climatic Regions
Highland Climates (highlands at same latitudes)
Classification of Climatic Regions
Desert (permanent moisture deficits)
Arid deserts (tropical and midlatitudes)
Semiarid steppes (tropical midlatitudes)
Dry, Arid, and Semiarid Climates
Dry subsiding air; rain shadow; away from
moisture-bearing air masses
1. Deserts
Precipitation supply roughly less than onehalf of the natural moisture demand
a. Hot Low-Latitude Desert Climates
b. Cold Midlatitude Desert Climates
Dry, Arid, and Semiarid Climates
2. Steppes
Precipitation supply roughly more than
one-half of the natural moisture demand
a. Hot Low-Latitude Steppe Climates
z Exists around the periphery of hot deserts
b. Cold Midlatitude Steppe Climates
z Mostly northern hemisphere
Arid and Semiarid Climates
Global Climate Change
Global Warming
CO2 raised from 280 ppm in 1750 to 375 ppm in 2003
CO2 is responsible for about 64% of the global warming
CH4 is increasing 1% a year
CH4 is responsible for about 19% of the global warming
N2O increased by about 17% in the last 1000 years
N2O by fertilizer use
Its effects is not fully understood yet
CFCs and other gases
Global Temperatures
Figure 10.28
Global Climate Change
Global Warming
Climate Models and Future Temperatures
Consequences of Global Warming
Political Action to Slow Global Warming
Carbon Dioxide Sources
Figure 10.29
Global Climate Systems
Climatology
Climate
Controlling factors/elements
Classification of climatic regions
Global climate changes