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Department of
(Assistant professor)
March 2017
1.Definition of Atmosphere
• Atmosphere: The
. The
•
•
layer of gases that surrounds the Earth.
It is a gaseous layer surrounding the earth. In
other words, we can say that
, called
atmosphere.
Yes, it is thin when compared to the size of the
earth. Yet, this thin layer has its own influences on
various processes that take place on earth.
.
In fact, it took millions of years to reach the present
condition by various processes. Along with its
development, life came into existence and evolved.
Atmosphere extends from a
However, about
Most of the mass of the
.
All the natural processes on earth are functioning
harmoniously.






Atmosphere is very important
.
It contains
in sufficiently large
quantities.
Constant concentration of oxygen is maintained through
oxygen cycle.
The oxygen cycle does not take place in isolation but it
takes place along with other
.
These cycles connect the atmosphere with
,
and
.
The atmosphere does not function by itself, but it
functions in conformity with other spheres on earth.
Atmosphere is the
and reaches the
earth’s surface or into the water.
It is a wonder, why solar radiation is mentioned as “lifesustaining” one. It is mentioned so, because, solar
radiation is the
, which thereby
supports all other life.
When solar radiation passes through the atmosphere,
happen.
, which is a part of our atmosphere.
from reaching the earth’s surface.
Earth is not heated by solar radiation uniformly due to its
inclination.
As a result, different weather patterns exist over the
earth. In order to compensate these differences, air sets
in motion resulting in winds and circulation of air. These
wind currents are of global scale as well as of local scale.
They are responsible for disastrous storms like cyclones,
dust storms, tornadoes etc. These wind currents also
influence water currents in the oceans; they in turn affect
the wind currents. Consequently, understanding the
atmosphere and its functions and behavior is quite
complex. However, with available knowledge, scientists
try to comprehend to the extent possible.
Thus, understanding of the atmosphere has become very
essential and important. All the above processes make
the atmosphere, a dynamic atmosphere.
In nutshell:
• Without atmosphere:– Life would be impossible on earth and living things would be
as helpless as fish without water
– We would not survive for more than a few minutes (oxygen )
– there could be no clouds, winds and rains
• Atmosphere acts as a great canopy /shelter/ to protect the
earth’s surface from the strong sun radiation and prevent
excessive loss of heat by night.
• The components of atmosphere (like ozone and atomic oxygen)
filter (absorb) the harmful ultra violet radiation of the sun.
• It protects the earth’s surface from the direct strike of meteors
that reach in the thermosphere and mesosphere burn from the
heat generated by air friction
1.1.3. Composition of Atmosphere
• The compositions of the atmosphere are
and
• The atmosphere is a mixture of
and
(water
vapor) that surrounds the earth like a blanket.
• Air is a mechanical mixture of gases, not a chemical compound.
As a result of this, in the atmosphere is composed the following
gases:: - Dry air, by volume, is
: - They are
, thereby producing the greenhouse effect.
The most common greenhouse gases include:Carbon dioxide (CO2)
Methane (
)
Nitrous oxide (N2O)
Ozone (O3)
Chlorofluorocarbons (CFCs: chiefly CFC-l3 (F-12) and
CF2C-l2 (F-12))
Hydrogenated halocarbons (HFCs and HCFCs)
Water vapor (H2O)
A. Reactive gas species: - are produced by the cycles of
sulphur, nitrogen and chlorine. These play key roles in acid
precipitation and in ozone destruction. The common
reactive gases include:Nitrogen species:-The reactive species of nitrogen are nitric
oxide (NO) and nitrogen dioxide (NO2).
Sulphur species:- species are sulphur dioxide (SO2) and is
sulfur trioxide (SO3)
A. Aerosols:
Impurities, such as dust, ashes, smoke, salt, etc., from both
natural and human sources are also present in the
atmosphere.
Collectively, these tiny solid or liquid suspended particles
of various compositions are called aerosols.
Some natural impurities found in the atmosphere are quite
beneficial.
Small, floating particles, for instance, act as surfaces on which
water vapor condenses to form clouds.
• However, most human-made impurities (and some natural
ones) are a nuisance, as well as a health hazard
• Permanent /uniform Gases and Variable Gases
es
• Permanent /Constant gases are the ones,
and
.
• Examples of uniform gases are:
(0.93%),
(78.09%),
(20.95%),
• Ar, Ne, He, H2, Kr, Xe are called
. Argon is the
largest trace gases in the atmosphere.
• Nitrogen and oxygen are the two major constant gases that make
up 99 percent of the air. Both are important to sustain life on earth.
Nitrogen constitutes 78.09% and oxygen 20.94 percent
b. Variable Gases
• Variable gases are
.
• The remaining
is constituted by
such as, argon, helium, krypton, xenon and also by variable
gases –
• Examples of variable gases are: water vapor (0-4%), CO2
(0.035%), CH4, N2O, O3, CFC. …….. [CH4, N2O, O3 and CFC
are called trace gases.]
In nutshell:
Atmosphere
has
nature/characteristics:-
the
following
; it can’t be felt
except when it is in motion; so we cannot see,
smell or test air.
It is
It is transplant to short wave
radiation but can absorb long wave (earth
radiation) (infra-red) radiation.
It
, since it can
be compressed its decreases with altitude.
1.1.4. Origin of atmosphere
• The origin of our earth’s atmosphere is
• The solar system is
.
• As there are no human then, any explanations about the
solar system are simply theories based on the observation
we make now.
• The
• The
.
• Such clouds are common between the stars in our galaxy
even today and astronomers now identified them and
think all stars, including the sun have formed from them.
• Evidence from these clouds, especially cosmic gas
suggests that first atmosphere probably consisted
mainly of Hydrogen (71%), Helium (27%) as well as
trace amounts of Ammonia and Methane. This is called
primordial atmosphere.
• However, the gaseous elements that comprised this
original atmosphere of the earth under went much
evolution.
• In the early stage of planet formation from interstellar
clouds, solar and gravitational effects probably resulted
in accretion of some gases and the subsequent escape
of others.
• When the earth was formed some 4.6 billion years ago,
it was probably too hot to retain any of the atmospheres
it had to begin with.
• Hydrogen and Helium escaped from the earth’s
atmosphere. In addition, the lower gravitational force of
the earths is unable to retain light gases such as hydrogen
and helium.
• Continuous out gassing, a process that expelled gases and
other materials form the earth’s interior, took place 4.6
billion years ago by volcanism and plate tectonics.
Volcanoes particularly emitted water vapor and carbon
dioxide with a little bit of nitrogen. It produced the earth’s
secondary atmosphere. The vast amounts of water vapor
formed clouds, which in turn produced rain. At this time,
the surface temperature was cool enough for water vapor
to condense in to water. Over a period of thousands of
years, the rain accumulated as rivers, lakes, basins and
oceans.
• These water reservoirs acted as sinks for
large amounts of carbon dioxide and
through chemical process become locked up
in the sedimentary rocks such as limestone.
The nitrogen, which is not chemically active
continued to accumulate in the atmosphere.
The earth’s atmosphere is unique among
the planets of the solar system since O2
have been added in the atmosphere over
time. Oxygen is the byproduct of
photosynthesis.
Evolutionist Theory
• This is the most widely
• According to this theory
• The first atmosphere is
.
• When the Earth was formed
, Earth’s
atmosphere was probably mostly
(H) and
(He) plus
, such as methane ( ) and
ammonia (
).
• The earth originated from
• The first atmosphere consists of
• But these gases (
) are very light gases.
• Over billions of year,
and
(energetic particles).
and
simply they are light, hence they are diffused to the
atmosphere.
• Volcanic emission
– The release of gases from rock through volcanic eruption (so-called outgassing) was the
.
– The primeval (ancient) atmosphere produced by the out-gassing was
mostly carbon dioxide (CO2) with some Nitrogen (N2) and water vapour
(H2O), and trace amounts of other gases.
• Hot springs
• Emission of water vapor, CO2, N2
– The first atmosphere would have consisted of gases
in the solar nebula, primarily hydrogen.
– As the solar nebula dissipated these gases would
have escaped, partly driven off by the solar wind.
– The
next
atmosphere,
consisting
largely
of
plus
and
, was
produced by out gassing from volcanism,
supplemented by gases produced during the late
heavy bombardment of Earth by huge asteroids.
– A major part of
emissions were soon
dissolved in water and built up carbonate sediments.
• Third atmosphere: The constant re-arrangement of
continents by plate tectonics influences the long-term
evolution of the atmosphere by transferring carbon
dioxide to and from large continental carbonate stores.
– Free oxygen did not exist in the atmosphere until
about
during the Great
Oxygenation Event and its appearance is indicated by
the end of the banded iron formations.
– Before this time, any oxygen produced by
photosynthesis was consumed by oxidation of reduced
materials, notably iron.
• The earth is surrounded by a thin layer of air, called, atmosphere.
The atmosphere, from the surface of earth extends up to 60,000
km.
• You may wonder how such a thickness would be called a thin layer.
Where, most of the mass of the atmosphere is found near the
planetary surface.
• It is near the earth’s surface from surface to about
.
This is due to the earth’s gravity, which pulls the atmospheric
constituents, towards its center.
.
• It is the thin layer, in which most of the atmospheric processes take
place. According to the concentration of the gases, atmosphere is
divided into:
: the lower region, extending from the surface of the
earth to a height of 80 to 100 km above the earth.
 In this layer, gases are more or less uniform in their chemical
composition.
2.
: it starts from the
and
– In this layer,
Concentration of
.
and hence,
.
• The atmosphere is composed of a series of
, and
.
• These layers vary in altitude and temperature, and they
do not mix together.
• The name is derived from the Greek word “tropos”
meaning to turn or mix because it has a great deal of
vertical mixing due to solar heating at the surface
(describes the layer’s convective and mixing
characteristics).
Major characteristics of the Troposphere: The lowest layer of the atmosphere which surrounds
the earth like
 It is the layer of atmosphere
 Within the troposphere, air circulates in great
vertical and horizontal convection currents,
constantly redistributing heat and moisture around
the globe.
 It is the zone where
 The composition are N2, O2, CO2, Ar, O3 (small
amount), aerosols and water vapour.
 The average depth of the troposphere is about
12km.
 Because
holds most air molecules close
to the earth’s surface, the troposphere is much
denser than the other layers:
 Throughout this layer, there is a general decrease
of temperature with increasing height at a mean
rate of about 6.5°C/1km (6.5°C/1000m). This is
called
 So lapse rate is a characteristics of Troposphere
The main reasons are:• The lower atmosphere in the troposphere is heated by
terrestrial re-radiation that is heat rising from the
surface of the earth not directly from the sun.
– So in the troposphere, the higher we go from the lower
atmosphere, the further we go from the source
of(terrestrial) heat
• The density of the atmosphere (air) decreases with
altitude.
• The troposphere is capped in most places by a
temperature inversion level (i.e., a layer of relatively
warm air above a colder layer) and in others by a zone
that is isothermal with height.
• A sudden reversal of this temperature gradient creates a
sharp boundary called the tropopause, which limits
mixing between the troposphere and upper zones.
Tropopause
• It is an isothermal layer (equal temperature)
• It is a zone of perfect calm (constant)
• It forms a boundary layer (transition zone) between
trop
• In some regions troposphere is broken down so there is
mixing between the two zones. Because it is mixed
(marked) by jet streams (very fast and high level wind).
• There are marked variations in the altitude of the
tropopause with latitude, from about 16km at the
equator, where there is strong heating and vertical
convective turbulence, to only 8km at the poles.
• So 12km is an average height (16 + 8 /2=12).
2. The Stratosphere (stratified sphere)
The name is derived from the Latin ‘stratum’ meaning a
layer – this describes its state of non - convective nature.
Major characteristics of the Stratosphere:• It is the next layer of atmosphere above the
troposphere.
• It extends from the
• In the stratosphere, there is a
• Thus, unlike the troposphere, the
relatively calm; so, commercial jets fly here.
is
There is so little mixing in the stratosphere that volcanic
ash or human-caused contaminants can remain in
suspension there for many years.
The composition are the same with stratosphere (N2, O2,
CO2, Ar, O3 (small amount), aerosols and water vapour)
but the exception is maximum ozone (O3) and little
water vapour.
There is no visible weather condition. That means
temperature increases with altitude.
This is called
So temperature inversion is the characteristics of
stratosphere.
Can you suggest the reason
why temperature increases
with increase altitude in the
stratosphere?
o The reason for the increased temperature with altitude in
the stratosphere is due
.
o This absorbed energy makes the atmosphere warmer
toward the top of the stratosphere.
o Because UV radiation damages living tissues, causing skin
cancer, genetic mutations, crop failures, this UV
absorption in the stratosphere also protects life on the
earth’s surface.
• Ozone gas is largely concentrated at about 30 kmcalled
(a place where there is
maximum ozone).
• Its upper part is called
(boundary b/n
stratosphere and mesosphere)
• The name is derived from the Greek word ‘
’ meaning
‘
’
• It is the layer of atmosphere directly
• Extending from
km above Earth’s surface.
• The boundary near 50 km, which separates stratosphere and
mesosphere, is called the
.
• The air at this level is
, which means
that only one-thousandth of all the atmosphere’s molecules is
above this level and 99.9% of the atmosphere’s mass is located
below it.
• Temperature falls rapidly with increasing altitude as there is no
(or little) water vapour, dust or Ozone to absorb the incoming
radiation.
• The top part (mesopause) has the lowest temperature close to 100oC; this layer is the
of the atmosphere.
• Has the
.
• Pressure is very low due to the lower density of the atmospheric
molecules.
• Is the darkest part of the atmosphere due to the scarcity of the
air molecules to reflect or scatter radiation
• Most meteorites which enter the mesosphere from space burn and
disintegrate as they experience increasing friction. Therefore, this
layer has meteoritic dust particles
• Extends upw
•
•
•
•
and temperature continuously rises
with increasing altitude throughout this layer called
.
The increase of temperature in the thermosphere is due to
the reaction between ultra-violet radiation with atomic
oxygen (O) and molecular nitrogen (N2).
These gases absorb a few solar energy raises temperature
into a greater degree.
The thermosphere is important in long-distance
communication because it reflects outgoing radio waves
back to Earth without the aid of satellites.
The warmest layer of the atmosphere
• It is electrically charged zone
• Nitrogen (N2) and
(O) are abundant in the
lower part of thermosphere (the ionosphere).
• These are the capacity to absorb the incoming very short
ultra-violet radiation (below 0.2 micro meters in wave
length).
• When these gases absorb the rays of the sun, they lose
their electrons and the ionosphere becomes full of
electrically charged particles.
• The loss of electrons from an atom is called the ionization
process.
• As the electrons move in the thermosphere, they cause an
inversion of temperature.
• Important in reflecting radio waves: B.B.C.
• The electrons of the ionosphere are also used for
communication because they can reflect radio-waves back
to the earth’s surface (known as ionospheric reflection of
radio waves).
•
•
•
•
•
Exo- means external, outer layer
Temperature reaches up to 1100oC
Light gases are
exist
Gravity reaches to
(0)
In the upper layer of the thermosphere (exosphere), negatively
charged electrons increasingly separated from neutron and proton
atoms by high energy radiation from the sun.
• In the magnetosphere (the outer most layer of the thermosphere)
there are only electrons (negative) and protons (positive) derived
from solar wind-plasma of electrically conducting gas.
Gas
Permanent
% By volume
Nitrogen
Oxygen
78.09
20.95
Variable Gases Carbon dioxide 0.03
Water Vapor
0.2-4
Ozone
0.00006
Inert Gases
Argon
(Inactive gases) Helium,
Neon, krypton
0.93
Trace
Non gaseous
Dust particles
Trace
Pollutants
Sulfur dioxide, Trace
Nitrogen oxide,
Methane, etc
Importance for weather & Other function ( Source )
Climate
Needs for plant growth
Produced
by
photosynthesis, reduced by
deforestation.
Absorbs long wave radiation Used by plants for photo
from
earth
keeps synthesis;
temperature steady;
Increased by burning fossil
has greenhouse effect
fuels and by deforestation
Source of cloud formation&
perception,
reflects
(absorbs)
incoming
radiation
Absorbs
incoming
UVradiation
Can reach 4 %, can be
stored as ice/snow
Absorbs / reflects incoming
radiation,
forms
condensation
nuclei
necessary
for
cloud
formation
Affects radiation, causes
acid rain
Volcanic dust, meteoritic
dust, soil erosion by wind
Reduced / destroyed by
chlorofluorocarbon CFCs
From
industry,
power
stations and car exhausts
• The word “weather” is used to denote the
• It shows short term variability in terms of:
• Is the day-to-day state of atmosphere and pertains to shortterm changes in conditions of
• Is constantly
.
• It results fundamentally from processes that attempt to
equalize differences in the distribution of net radiant energy
received from the sun.
• The weather is made up of different elements, which are measured
either by special instruments or are observed by a meteorologist.
• These measurements are then recorded and used in the making of
climate graphs and weather forecasts.
 Temperature is a physical quantity that is a measure of
 It is a measure of the local thermal energy of matter or radiation; it
is measured by a
, which may be calibrated in any of
various temperature scales,
etc., etc.
Many things depend on temperature, such as:
 physical
properties
of
materials
including
the phase (solid, liquid, gaseous or plasma), density, sol
ubility, vapor pressure, electrical conductivity.
 rate and extent to which chemical reactions occur
 the amount and properties of thermal radiation
emitted from the surface of an object
 speed of sound is a function of the square root of the
absolute temperature
Temperature scales
• Much of the world uses the Celsius scale (°C) for most
temperature measurements. It has the same
incremental scaling as the Kelvin scale used by scientists,
but fixes its null point, at 0°C = 273.15K, approximately
the freezing point of water (at one atmosphere of
pressure). The United States uses the Fahrenheit scale
for common purposes, a scale on which water freezes at
32 °F and boils at 212 °F (at one atmosphere of
pressure).
• 0°C = 273.15K = 32 °F & 1°C = 274.15K = 33.8 °F
• Insolation is a measure of solar radiation energy
received on a given surface area and recorded
during a given time.
• It is also called
and expressed as
"
" if recorded during an hour or
"
" if recorded
.
• The unit recommended by the
is
(MJ/m2) or
(J/mm2).
 Sunlight is a portion of the electromagnetic radiation
given off by the Sun, particularly infrared, visible, and
ultraviolet light. On Earth, sunlight is filtered through
the Earth's atmosphere, and is obvious as daylight
when the Sun is above the horizon.
 When the direct solar radiation is not blocked by
clouds, it is experienced as sunshine, a combination of
bright light and radiant heat. When it is blocked by the
clouds or reflects off other objects, it is experienced as
diffused light.
 The World Meteorological Organization uses the term
"sunshine duration" to mean the cumulative time
during which an area receives direct irradiance from
the Sun of at least 120 watts per square meter.
Precipitation is any product of the condensation
of atmospheric water vapour that falls under gravity.
The
main
forms
of
precipitation
include
drizzle, rain, sleet, snow, and hail.
Precipitation occurs when a
Fog and mist are not precipitation but suspensions,
because the water vapour does not condense sufficiently
to precipitate.
• Two processes, possibly acting together, can lead to air
becoming saturated: cooling the air or adding water
vapor to the air.
• Precipitation is a major component of the water cycle,
and is responsible for depositing the fresh water on
the planet.
• Approximately 505,000 cubic kilometers of water falls as
precipitation each year; 398,000 cubic kilometers) of it
over the oceans and 107,000 cubic kilometers over land.
• Given the Earth's surface area, that means the globally
averaged annual precipitation is 990 millimeters (39 in),
but over land it is only 715 millimeters (28.1 in).
The table below shows the weather element details.
SN
Element
Description
How it is measured
Units of measurement
1
Temperature
How hot or cold it is
By Thermometers,
found inside a
Stevenson Screen
Degrees Celsius ( c)
2
Insolation
Incoming solar radiation
3
Sunshine
The hours of sunshine
By a Sunshine
Mega joules per square metre
(MJ/m2)
Recorder Hours and minutes
4
Precipitation
By a Rain Gauge
Millimetres (mm.)
5
Humidity
Moisture from the sky
e.g. rain, snow etc.
The amount of water
vapour in the air
6
Cloud Cover
Relative Humidity (% of water
vapour that can be held by the
air at the actual temperature)
Oktas − eighths of the sky
7
Visibility
8
Air Pressure
By a Hygrometer
(wet and Dry Bulb
Thermometers)
It is observed by a
meteorologist
It is observed by a
meteorologist
By a Barometer
9
Wind Speed
By an Anemometer
Knots, or by the Beaufort Scale
10
Wind
Direction
By a Wind Vane
Points of the compass (north,
north−west etc), or bearing in
degrees
The amount of cloud in
the sky
How far you can see
The "weight" of the air
pushing on the surface
of the Earth
How fast the wind is
blowing
Where the wind is
blowing from
Kilometers
Hectopascals (although most
people know it as millibars)
• Is described as
(heat, moisture, and air movement) of an area over a
long period of time.
• It is the
• The
It is a condition in the atmosphere at any time or short
period of time. Weather conditions can change suddenly.
Today may be warm and sunny, tomorrow may be cool
and cloudy. Weather conditions include rain, snow, sleet,
hail, fog, mist, sunshine, wind, temperature and
thunderstorms.
Describes surface and atmospheric conditions over a
longer period or over a large geographical area.
Climate changes slowly, usually over decades, centuries
and thousands of years.
• In the study of climate and weather, the same elements temperature, moisture, pressure and wind are used.
Scope of Weather and Climate
• Scope of weather: The study of what causes
• Scope of climate: The study of
Significance of (studying) weather and climate
• The weather affects us in many different ways. The
study of weather and climate is important for
determined:
• Clothing type: the type of clothes that people wear
varies from season and season, and from climate of one
region to another.
• Housing condition: People construct houses that suit
the type of climate in which they are living.
• Food crops: the kinds of food crops grown vary
according to the variation in climate. Climate affects the
type of economic activity.
• Animal and plant life: the kinds of animals and plants
that live in certain environment are the result of climate.
Controls of Weather and Climate
• Both weather and climate differs from place to place and
form time to time due to the variation in the amount,
intensity and areal distribution of various climate elements.
• The factors that cause for such variation are termed as
controls of climate and weather.
Some of the controls of climate and weather are:• Latitude: is the position of place either north ward or south
ward of the equator that determines the length of the day,
intensity & duration of sunlight.
• As a result, places at lower latitude (around equator)
receive high angle of the sun which increases intensity
&vice versa.
• Altitude: Is the height of places asl. It has effect on
temperature
(Alt.↑To↓),
pressure
(Alt.↑P↓)
&
precipitation (Alt.↑ PPT↑).
• Distance from the sea (nearness to water bodies): water bodies
have warming and cooling effect on the surrounding land masses.
– This has a greater effect on temperature and rainfall
distribution. As a result, places far away from water bodies
have high temperature and less amount of rainfall. e.g. the
Sahara desert.
• Ocean currents: Are horizontal movements of ocean waters that
are caused by winds and difference in temperature. There are
two major types of ocean currents which we call warm and cold
ocean currents. Warm ocean currents that move from tropics
towards the poles have warming effect while cold ocean currents
that move from poles towards the tropics have cooling effect.
• Cloud cover: the presence of cloud cover in an area has a
significant influence on the temperature condition of a place.
With clear skies, temperature increases due to direct reach of
incoming solar radiation to the earth’s surface without any
reduction or absorption and reflection of it through clouds.
• Mountain barriers: landform barriers, particularly high
mountain ranges, influence the temperature of a place
by blocking the movements of moisture bearing winds
which finally control the weather and climate condition
of a locality.
• Aspect: In the northern hemisphere north facing slope
will have cold condition due to polar cold winds and
sheltered from insolation.
– In the southern hemisphere north facing slope has
high temperature (warming condition) due to north
warming conditions and exposure to the sun.
type of climate data
• max,/min, range ppt, temp, humidity, wind speed
sources of climate data
how to get climate data and import it to excel sheet
(CSV)
how to fill data gaps
– interpolation? Or?
• analysis in Excel environment
– basic analysis like mean, median, max/min, range,
• For what purpose and how we use Regression
• Data to ArcGIS environment
– major statistical method in climate studies
Climate graphs are line graph, bar graph or a combination of
both a bar graph and a line graph (climograph).
Temperature is shown on a line graph.
Rainfall is shown by a bar graph.
Temperature and Rainfall together may be shown
with climograph.
 A line chart or line graph is a type of chart which displays
information as a series of data points connected by
straight line segments.
 It is a basic type of chart common in many fields. A line
chart is often used to
– a time series – thus the line is often drawn
chronologically.
Structure
• A line chart is typically drawn bordered by two
perpendicular lines, called axes.
• The horizontal axis is called the x-axis and the vertical axis
is called the y-axis.
• Each axis represents one of the data quantities to be
plotted.
• Typically the y-axis represents the dependent variable and
the x-axis (sometimes called the abscissa) represents
the independent variable.
• The chart can then be referred to as a graph of ``Quantity
one versus quantity two, plotting quantity one up the y-axis
and quantity two along the x-axis.
B. Bar chart
• A bar chart or bar graph is a chart with rectangular bars
with lengths proportional to the values that they represent.
The bars can be plotted vertically or horizontally. A vertical
bar chart is sometimes called a column bar chart.
• One axis of the chart shows the specific categories being
compared, and the other axis represents a discrete value.
Some bar graphs present bars clustered in groups of more
than one (grouped bar graphs), and others show the bars
divided into subparts to show cumulate effect (stacked bar
graphs).
C.
A climograph is a graphical representation of
basic climatic parameters, which is monthly
average temperature and Precipitation, at a certain location. It
is used for a quick-view of the climate of a location.
One form of representation uses an overlapped combination of
a bar and line chart used to show the climate of a place over a
12 month period.
• Use following table to make
A. Line Graph
For Maximum temperature
For Minimum Temperature
For Maximum and Minimum Temperature both
B. Bar Graph to show Precipitation
C. Climograph to show Max.
Temperature and Precipitation
/
Min.
Cambridge 1971–2000 averages
Month
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Max Temp
[°C]
7.0
7.4
10.2
12.6
16.5
19.4
22.2
22.3
18.9
14.6
9.9
7.8
Min Temp
[°C]
1.3
1.1
2.9
4.0
6.7
9.8
12.0
11.9
10.1
7.1
3.7
2.3
Days of Air Frost
[days]
9.7
9.5
4.9
3.2
0.5
0.0
0.0
0.0
0.0
1.2
4.8
8.0
Sunshine
[hours]
55.5
72.6
107.0
145.8
189.7
180.0
191.3
186.9
141.6
115.0
68.1
47.7
Rainfall
[mm]
45.0
32.7
41.5
43.1
44.5
53.8
38.2
48.8
51.0
53.8
51.1
50.0