Download weather and climate

The
atmosphere is
a collection of
gases that makes
the Earth
habitable.
The
atmosphere is
an important part of what
makes Earth livable. It blocks
some of the Sun's dangerous
rays from reaching Earth. It
traps heat, making Earth a
comfortable temperature. And
the oxygen within
our atmosphere is essential for
life.
 Because
the Earth is round and not flat, the Sun's
rays don't fall evenly on the land and oceans. The
Sun shines more directly near the equator bringing
these areas more warmth. However, the polar
regions are at such an angle to the Sun that they
get little or no sunlight during the winter, causing
colder temperatures. These differences in
temperature create a restless movement of air and
water in great swirling currents to distribute heat
energy from the Sun across the planet. When air in
one region is warmer than the surrounding air, it
becomes less dense and begins to rise, drawing
more air in underneath. Elsewhere, cooler denser
air sinks, pushing air outward to flow along the
surface and complete the cycle.
 The
layer closest to the Earth
 The top of this layer is called “Tropopause”
 The gases in the troposphere is essential to
the life on earth.
 The temperature decreases with altitude in
troposphere but stops decreasing at
tropopause.
 Climatic changes occur here.
 The
second closest layer
 The top of stratosphere is called stratopause.
 The lower part of stratosphere is cold then it
gets warm at stratopause.
 This layer is clear and dry with steady winds
so the jet planes usually fly here.
 The ozone layer lies here that absorbs the
ultra violet rays.
 The
ozone layer resides in the stratosphere
and surrounds the entire Earth. UV-B
radiation from the Sun is partially absorbed
in this layer. As a result, the amount of UV-B
reaching Earth’s surface is greatly reduced.
UV-A is other solar radiation are not strongly
absorbed by the ozone layer. Human
exposure to UV-B increases the risk of skin
cancer, cataracts, and a suppressed immune
system. UV-B exposure can also damage
terrestrial plant life, single cell organisms,
and aquatic ecosystems.
 The
third closest layer.
 The
temperature drops down here.
 The
 The
fourth layer
temperature rise again as nitrogen and
oxygen atoms absorb solar energy.
 Located
from lower mesosphere to top
thermosphere.
 Here the air is highly ionized.
 Each layer of ionosphere reflects radio
waves.
 It is the home of Auroras
 The
bright dancing lights of the aurora are
actually collisions between electrically charged
particles from the sun that enter the earth's
atmosphere. The lights are seen above the
magnetic poles of the northern and southern
hemispheres. They are known as 'Aurora
borealis' in the north and 'Aurora australis' in the
south..
Auroral displays appear in many colours
although pale green and pink are the most
common. Shades of red, yellow, green, blue,
and violet have been reported