The Köppen Climate Classification System
Have you ever wondered why one area of the world is a desert, another a
grassland, and another a rainforest? Why are there different forests and
deserts, and why are there different types of life in each area? The answer is
climate.
Climate is the characteristic condition of the atmosphere near the earth's
surface at a certain place on earth. It is the long-term weather of that area
(at least 30 years). This includes the region's general pattern of weather
conditions, seasons and weather extremes like hurricanes, droughts, or rainy
periods. Two of the most important factors determining an area's climate are air
temperature and precipitation.
World biomes are controlled by climate. The climate of a region will determine
what plants will grow there, and what animals will inhabit it. All three
components, climate, plants and animals are interwoven to create the fabric of a
biome.
Some facts about climate
The sun's rays hit the equator at a direct angle between 23 ° N and
23 ° S latitude. Radiation that reaches the atmosphere here is at its
most intense.
In all other cases, the rays arrive at an angle to the surface and
are less intense. The closer a place is to the poles, the smaller the
angle and therefore the less intense the radiation.
Our climate system is based on the location of these hot and cold
air-mass regions and the atmospheric circulation created by trade
winds and westerlies.
Trade winds north of the equator blow from the northeast. South of
the equator, they blow from the southeast. The trade winds of the two
hemispheres meet near the equator, causing the air to rise. As the
rising air cools, clouds and rain develop. The resulting bands of
cloudy and rainy weather near the equator create tropical conditions.
Westerlies blow from the southwest on the Northern Hemisphere and
from the northwest in the Southern Hemisphere. Westerlies steer
storms from west to east across middle latitudes.
Both westerlies and trade winds blow away from the 30 ° latitude
belt. Over large areas centered at 30 ° latitude, surface winds are
light. Air slowly descends to replace the air that blows away. Any
moisture the air contains evaporates in the intense heat. The
tropical deserts, such as the Sahara of Africa and the Sonoran of
Mexico, exist under these regions.
Seasons
The Earth rotates about its axis, which is tilted at 23.5 degrees.
This tilt and the sun's radiation result in the Earth's seasons. The
sun emits rays that hit the earth's surface at different angles.
These rays transmit the highest level of energy when they strike the
earth at a right angle (90 °). Temperatures in these areas tend to be
the hottest places on earth. Other locations, where the sun's rays
hit at lesser angles, tend to be cooler.
As the Earth rotates on it's tilted axis around the sun, different
parts of the Earth receive higher and lower levels of radiant energy.
This creates the seasons.
World Biomes
A biome is a large geographical area of distinctive plant and animal
groups, which are adapted to that particular environment. The climate
and geography of a region determines what type of biome can exist in
that region. Major biomes include deserts, forests, grasslands,
tundra, and several types of aquatic environments. Each biome
consists of many ecosystems whose communities have adapted to the
small differences in climate and the environment inside the biome.
All living
things are
closely related
to their
environment. Any
change in one
part of an
environment,
like an increase
or decrease of a
species of
animal or plant,
causes a ripple
effect of change
in through other
parts of the
environment.
The earth
includes a huge
variety of
living things,
from complex
plants and
animals to very
simple,
one-celled
organisms. But
large or small,
simple or
complex, no
organism lives
alone. Each
depends in some
way on other
living and
nonliving things
in its
surroundings.
To
understand a
world biome,
you need to
know:
-
What the
climate
of the
region
is like.
-
Where each biome is found and and what its geography is like.
-
The
special adaptations of the vegetation.
-
The
types of animals found in the biome and their physical and
behavioral adaptations to their environment.
Ecological
Relationships
of Biomes
The survival
and well
being of a
biome and
its
organisms
depends on
ecological
relationships
throughout
the world.
Even changes
in distant
parts of the
world and
its
atmosphere
affect our
environment
and us. The
eruption of
a volcano in
Mexico, or
Southeast
Asia can
bring the
temperature
of the whole
world down a
few degrees
for several
years.
Köppen Climate Classification System
The Köppen Climate Classification System is the most widely used for
classifying the world's climates. Most classification systems used
today are based on the one introduced in 1900 by the Russian-German
climatologist Wladimir Köppen. Köppen divided the Earth's surface
into climatic regions that generally coincided with world patterns of
vegetation and soils.
The Köppen system recognizes five major climate types based on the
annual and monthly averages of temperature and precipitation. Each
type is designated by a capital letter.
A - Moist Tropical Climates are known for their high temperatures
year round and for their large amount of year round rain.
B - Dry Climates are characterized by little rain and a huge daily
temperature range. Two subgroups, S - semiarid or steppe, and W -
arid or desert, are used with the B climates.
C - In Humid Middle Latitude Climates land/water differences play a
large part. These climates have warm,dry summers and cool, wet
winters.
D - Continental Climates can be found in the interior regions of
large land masses. Total precipitation is not very high and seasonal
temperatures vary widely.
E - Cold Climates describe this climate type perfectly. These
climates are part of areas where permanent ice and tundra are always
present. Only about four months of the year have above freezing
temperatures.
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Further subgroups are designated by a second, lower case
letter which distinguish specific seasonal characteristics of
temperature and precipitation.
f - Moist with adequate precipitation in all months and
no dry season. This letter usually accompanies the A, C,
and D climates.
m - Rainforest climate in spite of short, dry season in
monsoon type cycle. This letter only applies to A
climates.
s - There is a dry season in the summer of the respective
hemisphere (high-sun season).
w - There is a dry season in the winter of the respective
hemisphere (low-sun season).
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To further denote variations in climate, a third
letter was added to the code.
a - Hot summers where the warmest month is over
22°C (72°F). These can be found in C and D
climates.
b - Warm summer with the warmest month below 22°C
(72°F). These can also be found in C and D
climates.
c - Cool, short summers with less than four
months over 10°C (50°F) in the C and D climates.
d - Very cold winters with the coldest month
below -38°C (-36°F) in the D climate only.
h - Dry-hot with a mean annual temperature over
18°C (64°F) in B climates only.
k - Dry-cold with a mean annual temperature under
18°C (64°F) in B climates only.
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Köppen
Classification & Biomes
| Cold
Climate |
Dry Climate
|
Temperate Climate |
Tropical Climate
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