it is about introduction of climatology

1. INTRODUCTION TO
CLIMATOLOGY
GLOBAL CLIMATE

2. INTRODUCTION
Definition of Climate: Climate is integration in time of the
physical states of the atmospheric environment, characteristics of a
certain geographical region.
Weather is the momentary state of atmospheric environment at a certain
location .
Climate can be called the integration of time of weather condition.
Climate has 4 major elements:-
EARTH – soil
WATER – humidity
FIRE – sun and temperature
AIR – wind

3. It is Scientific study of climate
is called climatology
WHAT IS CLIMATOLOGY ?
• The purpose of studying climatology is to achieve maximum human
comfort both indoor as well as outdoors by utilizing maximum natural
energy and resources.
• The earth receives almost all its thermal energy from sun in the form of
radiations and sun’s rays is the most dominating factor.
• Heat received at a given point on earth depends on angle of incidence,
atmospheric conditions (haze, clear sky), length of the day.

4. The earth is divided in
to three major climatic
zones tropical ,
temperate , polar

5. CLIMATE ZONE

6. CLIMATE MAP

7. WEATHER CLIMATE
• Refer to small area
• Short Period
• Change from time to time
• Every place has a different
weather conditions
(e.g : rainy day, sunny day)
• Involves large area
• Long Period
• Doesn’t change – fixed/suits every
area
• Same climate within each area (e.g :
Tropical, Mediterranean)
WEATHER VS CLIMATE

8. Climate is the average weather in a
place over many years. while the
weather can change in just a few
hours, climate takes hundreds,
thousands, even millions of years to
change.
DIFFERENCE BETWEEN WEATHER AND CLIMATE.

10. Climate: at any point on earth Determined by:
1. Movement Of The Atmosphere
2. The Proximity Of The Oceans,
3. Latitude And Altitude Of The Location
Climate is also affected by:
1. The Sun,
2. By Changes In The Orbit Of The Earth,
3. By Human Activities, Particularly The Burning Of Fossil
Fuels, Which May Lead To A Greenhouse Effect.
4. Seasons Happened Because Of Earth’s Tilt. (More Solar Radiation Are
Received By Earth In Northern Winter.)

11. GLOBAL CLIMATIC FACTORS
Quality of Solar Radiation
Quantity of Solar Radiation
Tilt of the Earth’s Axis
Radiation of the Earth Surface

12. 1. Quality of Solar Radiation
• The earth receives almost all its energy from the sun in the
form of radiations.
• Thus, the SUN is the dominating influence on climate.
• Some of the shorter wave length are absorbed by the
atmosphere and radiated at much longer wave length

13. 1. Quality of Solar Radiation (cont’d)
☼ According to human means of perception,
we can distinguish :
a. ultra-violet radiation, 290 – 380 nm (producing
photo-chemical effects, bleaching, sunburn, etc)
b. visible light, 380 (violet) – 700 (red) nm
c. short infra-red radiation, 700 – 2300 nm, (radiant
heat with some photo-chemical effects)

14. 2. Quantity of Solar Radiation
• The intensity of radiation reaching the upper surface
of the atmosphere is taken as the solar constant
• The earth moves around the sun in a slightly
elliptical orbit.

15. 2. Quantity Of Solar Radiation

16. 3. Tilt of The Earth’s Axis
• The Earth spins slowly around its own axis, and makes a full turn with
respect to the Sun. This is called Rotation and Revolution.
• The earth rotates around its own axis (Rotational Axis)
• Each complete rotation making a day = 24hour/day (1000 miles/hour)
• Due to the tilted position, however, the area receiving the maximum
intensity moves north and south between the tropic of Cancer (latitude
23.5ºN) and the tropic of Capricorn (latitude 23.5ºS).
• This is the main cause of seasonal changes.

17. Earth
• The direction of rotation of
the Earth can be thought of
as
– Counterclockwise at the north pole, or
– From left to right (eastward) at the equator.
– Parallels of latitude divide the globe
crosswise into rings.
– Meridians of longitude divide the globe from
pole to pole.

18. Axis Of Earth Affecting Climate
• During the year, the seasons change depending on the amount of sunlight
reaching the Earth as it revolves around the Sun.
The seasons are caused as the Earth, tilted on its axis, travels in a loop
around the Sun each year. Summer happens in the hemisphere tilted
towards the Sun, and winter happens in the hemisphere tilted away from
the Sun.

19. • TILT OF AXIS OF EARTH
During the year, the seasons change depending on the amount of
sunlight reaching the Earth as it revolves around the Sun.
The seasons are caused as the Earth, tilted on its axis, travels in a loop
around the Sun each year. Summer happens in the hemisphere tilted
towards the Sun, and winter happens in the hemisphere tilted away from
the Sun.
Earth-Sun Relationship

21. SUN PATH
Sun Path Diagrams Are
Representations Of The
Sun's Path Across The Sky On
A Flat Surface.
They Are Used To Easily And
Quickly Determine The
Location Of The Sun At Any
Time Of The Day And At
Any Time Of The Year.

22. Components of Sun
Path Diagram

23. Components of Sun
Path Diagram

24. sun path
Location of the Sun position
depends on two factors:
• Altitude angle
• Azimuth angle
Altitude angle:
Vertical angle the sun makes
with the horizontal ground
plane.
At sunset/sunrise - 0°
•At noon - 90°
Azimuth angle:
Angle with the horizontal
plane measured from true
North.
Azimuth
Altitude

25. Different latitudes and their sun path diagrams
24N 32N 40N 52N

26. 4. Radiation at The Earth’s Surface
• The earth-sun relationship affects the
amount of radiation received at a
particular point on the earth’s surface in
three ways :
1
• The cosine law
2
• Atmospheric depletion
3
• Duration of sunshine

27. 4. Radiation at The Earth’s Surface
1. The cosine law
– which states that the intensity on a tilted surface equals the
normal intensity times the cosine of the angle of incidence
β
β
B
C
Figure shows how the same amount of radiation is distributed over a larger
area, therefore less radiation falls on unit area.

28. 4. Radiation at The Earth’s Surface
2. Atmospheric Depletion
– The observation of radiation by ozone, vapors and dust
particles in the atmosphere.
– The lower the solar altitude angle, the longer the path of
radiation through the atmosphere = smaller part reaches
Earth’s surface.

29. 4. Radiation at The Earth’s Surface
3. Duration of sunshine
– The length of the daylight period
C
A
B
D
AB > CD
Earth
Atmosphere
Figure above indicates the geometrical relationship between
solar altitude and path of radiation through the atmosphere.

30. The Earth’s Thermal Balance
The total amount of heat absorbed by earth is each year is balanced by a
corresponding heat loss. This heat releases by three processes
1. – By long wave radiation to cold
outer space (84% is reradiated by
atmosphere and 16% escapes in
space)
2. - By evaporation : the earth’s surface
is
cooled,as liquid water changes into
vapour and mixes with air.
3. - By convection – air heated by
contact
with the warm earth surface becomes
lighter and rises to the upper
atmosphere,
where it dissipates its heat to space

31. Wind
• Planetary Winds
– Westerlies
– Easterlies
– Trade winds
• Local Winds
– These winds blow over
small areas
– Unlike planetary winds,
local winds can change
speed and direction
frequently
– These are the winds we
feel on the ground
– They are influenced by
local conditions and
local temperature
variations

32. Effects Of Wind
 Air moving parallel to the ground is
called wind
 Air moving up or down is called a
current
 The Coriolis effect causes wind
flowing from high pressure to low
pressure to curve as the wind moves
 In the Northern Hemisphere, the
Coriolis effect causes things to curve
to the Right
 In the Southern Hemisphere, the
Coriolis effect causes things to curve
to the Left

33. Global wind patterns for January
Global wind patterns for July
Source: http://www.weather-climate.org.uk/12.php

34. Globale Wind Pattern

35. • TOPOGRAPHY
Temperature decreases with altitude, so mountainous regions, plateaus
etc can have cooler than expected temperatures (hence glaciers on Mt
Kilimanjaro near the Equator).
2nd - aspect. the orientation of a slope in higher latitudes can affect the
local climate; south facing slopes in northern extra-tropical regions (say
Canada) will be warmer and get more hours of sunlight than north facing
slopes.
As stated by the other respondent, mountain ranges can act as barriers to
wind and rainfall, with much of the rain falling on the windward side and
top of the mountain and the lee of the mountain in 'rainshadow', i.e with
little rain.
Mountains can also control local winds.

36. Factors That Affect Climate

37. Precipitation
• Precipitation includes water in all its forms rain, snow, hail or dew
• It is usually measured in millimeters (mm) by using a rain gauge
• Rains in warm climates tends to make the built environment and
surrounding microclimate cooler .
CLOUD COVER
Regulates the amount of solar radiation reaching the earth’s surface.
Thus a cloudy day is cooler than a day we have a clear sky. Similarly at
night when the earth is in cooling mode it cools off quickly under the
clear sky than a cloudy one.
Measured in % of clear sky

38. Climate Classification

39. Climate Of India
 Hot and Dry
 Warm and Humid
 Moderate
 Cold & Cloudy
 Cold & Sunny
 Composite

40. Climate characteristics: Hot and dry
• Flat, sandy and rocky surface
• Spare vegetation
• Very less ground water and surface water sources
Topography
• Very high radiation levels and ground heats faster in the day
• Summer temp: 40-45 degrees(day) and 20-30 degrees(night)
• Winter temp: 05-25 degrees(day) and 0-10 degrees(night)
• High diurnal temperature ranges
Sun
• Very low humidity levels in the range of 25% to 40% due to no
vegetation and water sources.
• Low rainfall of about less than 500mm annually in the region
Humidity
• Hot winds and sandstorm experience during the day. Nights are
cooler and pleasantWinds
• Clear sky conditions gets in more radiation and causes glare
• Heat collected by the ground during the day is reradiated to the
atmosphere due to clear nigh skies and hence cooler nights.
Cloud Cover

41. What Needs To Be Done
Control of solar
radiation
Control of hot summer
winds
Resisting heat gains
through shading,
reducing exposed areas
and controlling
ventilation pattern
Designing for water
bodies to add moisture
to the dry air and lower
temperature
Heat emitted through
surrounding features
and ground during the
afternoon should be
avoided

42. Climate Characteristics: Warm And Humid
• Covers the coastal part of India and hence the proximity to
water.
• High humidity levels gives scope for abundant vegetation
Topography
• Diffuse radiation is more due to sky cover(cloudy)
• Summer temp: 30-35 degrees(day) and 25-30 degrees(night)
• Winter temp: 25-30 degrees(day) and 20-25 degrees(night)
• Low diurnal temperature ranges
Sun
• Very high humidity levels in the range of 75% to 90% due to
the proximity to the coast.
• Heavy rainfall more than 1200mm annually in the region
Humidity
• Wind from 1 or 2 prevailing directions with speed from very
low to very high.Winds
• Mostly cloudy conditions which gets in diffuse solar radiation
• But clear sky conditions gets in harsh radiations to touch the
ground surface.
Cloud Cover

43. What Needs To Be Done
Ventilation or the
accessibility to wind is
important for cooling of the
human body
Cross ventilation will
promote heat loss
Reduce heat gains by
providing shading
Provision of quick drainage
of water during the
monsoon spells

44. Climate characteristics: Moderate
• Hilly or high-plateau regions with fairly abundant
vegetationTopography
• The solar radiation more or less the same throughout the year.
• Summer temp: 35-30 degrees(day) and 24-17 degrees(night)
• Winter temp: 33-27 degrees(day) and 18-16 degrees(night)
• Temperatures are neither too hot nor too cold
• High diurnal temperature ranges
Sun
• Low humidity levels in the range of 20 – 55% and 50%
to 90% during monsoons.
• Rainfall of about 1000mm
Humidity
• High wind speed during summers
• Wind speed and direction generally depends on
topography
Winds
• Generally clear sky conditions throughout the yearCloud Cover

45. WHAT NEEDS TO BE DONE
Providing cross ventilation to
promote heat loss
Reduce heat gains by
providing shading

46. Climate characteristics: Composite
• A variable landscape and seasonal vegetation
• Covers most parts of central India
Topography
• The intensity of solar radiation is very high in summers
• Lower intensity in monsoons with mostly diffuse radiation
• Summer temp: 43-32 degrees(day) and 32-27 degrees(night)
• Winter temp: 25-10 degrees(day) and 10-04 degrees(night)
Sun
• High humidity levels in the range of 55%-95% during
monsoons and low humidity other year round in the range of
20% to 25%
• Rainfall varies from 500 to 1300mm
Humidity
• Strong winds from SE during monsoons and cold dry winds
from the NE
• In summers the winds are hot and dusty
Winds
• The sky is overcast and dull in the monsoon, clear in winter
and frequently hazy in summers.
Cloud
Cover

47. What Needs To Be Done
Control of solar
radiation
Control of hot
summer winds
Resisting heat gains
through shading,
reducing exposed
areas and controlling
ventilation pattern
Maximising cross
ventilation in the
monsoons to cater to
high humidity levels
Heat emitted through
surrounding features
and ground during the
afternoon should be
avoided

48. Climate Characteristics: Cold and Cloudy
• These are generally highland regions having abundant
vegetation in summer.Topography
• The intensity of solar radiation is low in winter with a
high percentage of diffuse radiation.
• Summer temp: 30-20 degrees(day) and 27-17
degrees(night)
• Winter temp: 8-4 degrees(day) and 4-3 degrees(night)
Sun
• High humidity levels in the range of 70%-80%
throughout the year
• Rainfall of 1000mm distributed evenly throughout the
year
Humidity
• Cold winds in the winter seasonWinds
• The sky is overcast for most part of the year except
during the brief summer.Cloud Cover

49. What Needs To Be Done
Protection from cold winds
Resisting Heat loss through
insulation
Capturing direct solar
radiations in the living
spaces

50. Climate characteristics: Cold and Sunny
• The region is mountainous, has little vegetation, and is
considered to be a cold desert.
Topography
• Intense solar radiations with a very low percentage of diffuse
radiation
• Summer temp: 24-17 degrees(day) and 11-04 degrees(night)
• Winter temp: 8- -7 degrees(day) and 0- -14 degrees(night)
Sun
• Very low humidity level ranging from 10% to 50%
• Rainfall of less than 200mm in a year
Humidity
• Occasionally intense cold winds in the regionWinds
• The sky is fairly clear throughout the year with a cloud cover
of less than 50%.
Cloud Cover

51. What Needs To Be Done
Resisting Heat loss through
insulation
Capturing direct solar radiations in
the living spaces

52. Microclimate analysis

53. Local Factors
Landform Vegetation
Water bodies
Street widths &
orientation
Open spaces &
built forms

54. Reflection
• Can you define climate and weather?
• What are the differences of climate and
weather?
• Named and explain global climatic factors.