Basic of atmospheric information

1. Atmospheric Layers Of Earth
Presented By
Mandar Mahindrakar
Department Of Geology
Govt.Institute Of Science
Aurangabad

2. Introduction
 The atmosphere is a mixture of different gases, particles and aerosols
collectively known as air which envelops the Earth.
 The atmosphere protects us by filtering out deadly cosmic rays,
powerful ultraviolet (UV) radiation from the Sun, and even meteors on
collision course with Earth.
99% of the mass of the atmosphere lies below about 25 to 30km
altitude, whilst 50% is concentrated in the lowest 5km (less than the
height of Mount Everest).
The two most abundant gases are nitrogen (78% by volume) and
oxygen (21% by volume), and together they make up over 99% of the
lower atmosphere.
In addition to nitrogen and oxygen, air contains a number of trace gases,
including the noble gases, greenhouse gases and ozone.
 significant variations in temperature and pressure with altitude, which
define a number of atmospheric layers, including the troposphere,
stratosphere, and mesosphere. Beyond about 50 miles (80 kilometers)
altitude, the air is very very thin indeed
Layers used to describe the outer reaches of the atmosphere include
the thermosphere, the ionosphere, the exosphere and the
magnetosphere. Another well-known layer is the ozone layer, residing in
the stratosphere and protecting life below from the harmful effects of

3. Nitrogen,7
8
Oxygen,21
Argaon,0.8
Nobal
Gas,0.1
Hydrogen,
0.1

5. Troposphere
The lowest layer of the
atmosphere is called the
troposphere. It ranges in
thickness from 8km at the poles
to 16km over the equator
The troposphere is denser
than the layers of the
atmosphere above it (because
of the weight compressing it),
and it contains up to 75% of the
mass of the atmosphere.
The troposphere is the layer
where most of the world's
weather takes place. Since
temperature decreases with
altitude in the troposphere
 Nearly all atmospheric water
vapor or moisture ,clouds is
found in the troposphere.

6. Stratosphere
The stratosphere is the second
major layer of the atmosphere. It
lies above the troposphere and is
separated from it by the
tropopause
It occupies the region of
atmosphere from about 12 to 50
km
The stratosphere defines a layer
in which temperatures rises with
increasing altitude
This rise in temperature is
caused by the absorption of
ultraviolet (UV) radiation from the
Sun by the ozone layer
Consequently the stratosphere is
almost completely free of clouds or
other forms of weather,provides
some advantages for long-distant
flight because it is above stormy
weather and has strong, steady,
horizontal winds.

7. Mesosphere
The mesosphere (literally
middle sphere) is the third
highest layer in our atmosphere
Occupying the region 50 km to
80 km above the surface of the
Earth
Temperatures in the
mesosphere drop with
increasing altitude to about -
100°C. The mesosphere is the
coldest of the atmospheric
layers.
In fact it is colder then
Antarctica's lowest recorded
temperature. It is cold enough to
freeze water vapor into ice
clouds
The mesosphere is also the
layer in which a lot of meteors
burn up while entering the
Earth's atmosphere. From the

8. Thermosphere
The thermosphere
(literally "heat sphere") is
the outer layer of the
atmosphere
the thermosphere, from
80 to 550 km above the
Earth's surface
Within the thermosphere
temperatures rise
continually to well beyond
1000°C.
The few molecules that
are present in the
thermosphere receive
extraordinary amounts of
energy from the Sun,
causing the layer to warm
to such high temperatures

9. Ionosphere
The ionosphere is a layer of ionized air in the atmosphere extending
from almost 80 km above the Earth's surface altitudes of 600 km and
more
Technically, the ionosphere is not another atmospheric layer. It
occupies the same region of the upper atmosphere as the
thermosphere.
In this region of the atmosphere the Sun's energy is so strong that it
breaks apart molecules and atoms of air, leaving ions (atoms with
missing electrons) and free-floating electrons.
The ionosphere is the region of the atmosphere where the auroras
occur.
Ionization of air molecules in the ionosphere is produced by
ultraviolet radiation from the Sun, and to a lesser extent by high-energy
particles from the Sun and from cosmic rays.
The large number of free electrons in the ionosphere allows the
propagation of electromagnetic waves.
Radio signals - a form of electromagnetic radiation - can be
"bounced" off the ionosphere allowing radio communication over long
distances.

11. Exosphere
The exosphere is the
highest layer of the
atmosphere.
Together with the
ionosphere, it makes up the
thermosphere.
The exosphere extends to
10,000 km above the
Earth's surface. This is the
upper limit of our
atmosphere
In this region of the
atmosphere, hydrogen and
helium are the prime
components and are only
present at extremely low
densities.
This is the area where
many satellites orbit the
Earth.

12. Magnetosphere
The magnetosphere extends into the vacuum of space from approximately
80 to 60,000 kilometers on the side toward the Sun, and trails out more than
300,000 kilometers away from the Sun.
Earth's magnetic field protects us from the harmful effects of the solar wind.
The Earth is like a huge magnet, and its magnetic influence extends far into
space.
It is made up of positively charged protons and negatively charged electrons.
The solar wind would singe our atmosphere if not for the Earth's magnetic
field.
Many of the remaining particles that are given off by the Sun are
concentrated into belts or layers called the Van Allen radiation belts.

13. Coriolis Force
 The Coriolis force is a force which acts upon any moving body in an
independently rotating system.
The most well known application of the Coriolis force is for the
movement or flow of air across the Earth.
The effect is named after the French physicist Gaspard de Coriolis
(1792-1843), who first analyzed the phenomenon mathematically
Moving air undergoes an apparent deflection from its path, as seen
by an observer on the Earth. This apparent deflection is the result of
the Coriolis force
Therefore, slowly blowing winds will be deflected only a small
amount, while stronger winds will be deflected more.
Likewise, winds blowing closer to the poles will be deflected more
than winds at the same speed closer to the equator.
The Coriolis force only acts on large objects like air masses moving
considerable distances of Small objects,
 for example ships at sea, are too small to experience significant
deflections in direction due to the Coriolis Force.

15. Ozone Layer
The ozone layer is a layer of ozone particles scattered between 19 and 30
kilometers (12 to 30 miles) up in the Earth's atmosphere, in a region called the
stratosphere.
The concentration of ozone in the ozone layer is usually under 10 parts
ozone per million. Without the ozone layer, ultraviolet (UV) radiation from the
Sun would not be stopped from entering the Earth's atmosphere and arriving
at the surface, causing damage to most living species.
Ozone is created in the stratosphere when highly energetic solar radiation
strikes molecules of oxygen (O2) and causes the two oxygen atoms to split
apart.
 If a freed atom bumps into another O2, it joins up, forming ozone (O3). This
process known as photolysis
In an unpolluted atmosphere there is a balance between the amount of
ozone being produced and the amount of ozone being destroyed. As a result,
the total amount of ozone in the stratosphere remains relatively constant
Ozone's unique physical properties allow the ozone layer to act as our
planet's sunscreen, providing an invisible filter to help protect all life forms from
the Sun's damaging ultraviolet (UV) rays.
Most incoming UV radiation is absorbed by ozone and prevented from
reaching the Earth's surface. Without the protective effect of ozone, life on
Earth would not have evolved in the way it has.

17. Jet Streams
The jet stream is a current of fast moving
air found in the upper levels of the
troposphere which blow from west to east
due to the Earth's rotation.
This rapid current is typically thousands of
kilometers long, a few hundred kilometers
wide, and only a few kilometers thick.
Jet streams are usually found somewhere
between 10-15 km (6-9 miles) above the
Earth's surface.
 Wind speed within jet streams can range
from between 50 -and 300 miles per hour.
The position of the jet stream denotes the
location of the strongest temperature
contrasts between different latitudes on the
Earth surface. Consequently, the strongest
jet streams usually occur during the winter
months,
 when large temperature differences exist
between low and high latitudes. There are
two main jet streams - the subtropical jet
stream at about 30 degrees latitude and the