this presentation is based on ch. indian climate from geography text book of 9th class.....

1. TOPIC - MECHANISM OF
INDIAN CLIMATE

2. 1. Introduction
2. Comprehensive map of
India
3. Meteorological chart
4. Meteorological chart of
the world
5. What is climate?
6. Climate and Terrestrial
biomes.
7. Where does the word
climate came from?
8. Climatic zones
9. Asia: Climate map
10. Temperature and
precipitation scales
11. Precipitation Map
12. Vegetation classification
13. El Niño
14. Indian climate
15. Temperature map of
world
16. Climatic map of India

3. INTRODUCTION
 India (in Hindi, Bharat), officially Republic of
India, federal democracy in southern Asia and a
member of the Commonwealth of Nations,
comprising, with Pakistan and Bangladesh, the
subcontinent of India. India is the seventh-largest
country in the world and the second most
populous, after China. India is bordered on the
north by Afghanistan (if Pakistan-controlled
Kashmir is included), Tibet, Nepal, China, and
Bhutan; on the south by the Palk Strait and the
Gulf of Mannar, which separate it from Sri Lanka.

4. The Indian Ocean; on the west by the Arabian
Sea and Pakistan; on the east by Myanmar
(Burma), the Bay of Bengal and Bangladesh,
which almost cuts off north-east India from the
rest of the country. With Jammu and Kashmir
(the definitive status of which has not been
determined), India has an area of 3,165,596 sq
km (1,222,243 sq mi). The capital of India is New
Delhi, and the country’s largest cities are
Mumbai (formerly Bombay), Delhi, and Kolkata
(formerly Calcutta).

5. comprehensive
map of India

7. Meteorological charts
 Most people are familiar with meteorological charts from
daily weather forecasts on television and in the
newspapers. The charts are compiled using a system of
mathematical equations, known as numerical weather
prediction (NWP), that are combined into a complex,
computer-based model of the atmosphere’s behaviour.
The model is applied to observations of real weather
events in particular areas, or points, on the Earth’s
surface; each point includes several levels, or “parcels”, of
air up through the atmosphere. The movement of these
parcels through time is calculated to provide the
forecast.

8. Meteorological chart of world

9. What is climate?
 Climate, the long-term effect of the Sun's radiation on
the rotating Earth's varied surface and atmosphere. It
can be understood most easily in terms of annual or
seasonal averages of temperature and precipitation.
Land and sea areas, being so variable, react in many
different ways to the atmosphere, which is constantly
circulating in a state of dynamic activity. Day-by-day
variations in a given area constitute the weather, whereas
climate is the long-term synthesis of such variations
(both can be viewed as subdisciplines of meteorology).

10. Weather is measured by thermometers, rain
gauges, barometers, and other instruments, but
the study of climate relies on statistics. Today, such
statistics are handled efficiently by computers. A
simple, long-term summary of weather changes,
however, is still not a true picture of climate. To
obtain this requires the analysis of daily, monthly,
and yearly patterns. Investigation of climate
changes over geological time is the province of
palaeoclimatology, which requires the tools and
methods of geological research.

11. Climate and Terrestrial
biomes
Regional climates may
be described in terms of
five different types of
biomes. A biome is
characterized by the
particular combination
of temperature,
humidity, vegetation,
and associated animal
life in an area. This map
shows the distribution
of the world’s major
biomes: rain forest and
savanna, mixed forest
and grasslands, needle-
leaf and mixed forests,
steppe and desert, and
tundra and icecaps.

12. Where does the word climate
came from?
 The word climate comes from the Greek klima, referring
to the inclination of the Sun. Besides the effects of solar
radiation and its variations, climate is also influenced by
the complex structure and composition of the
atmosphere and by the ways in which it and the ocean
transport heat. Thus, for any given area on Earth, not
only the latitude (the Sun's inclination) must be
considered but also the elevation, terrain, distance from
the ocean, relation to mountain systems and lakes, and
other such influences.

13. Climatic zones
 Climates are described by agreed-upon codes or
by descriptive terms that are somewhat loosely
defined but nevertheless useful. On a global
scale, climate can be spoken of in terms of zones,
or belts, that can be traced between the equator
and the pole in each hemisphere. To understand
them, the circulation of the upper atmosphere, or
stratosphere, must be considered, as well as that
of the lower atmosphere, or troposphere, where
weather takes place.

14. Upper atmospheric phenomena were little
understood until the advent of such advanced
technology as rocketry, high-altitude aircraft, and
satellites. Ideally, hot air can be thought of as rising
by convection along the equator and sinking near
the poles. Thus, the equatorial belt tends to be a
region of low pressure and calms, interrupted by
thunderstorms associated with towering cumulus
clouds. Because of the calms, this belt is known as
the doldrums. It shifts somewhat north of the
equator in the northern summer and south in the
southern summer.

15. Asia: Climate map
Asia experiences
virtually every
climatic condition
on earth. With such
an expansive, varied
terrain, comprising
so many striking
topographical
features, the
continent is at once
warm, cold, wet,
and dry.

16. Temperature and precipitation
scales.
 Temperature is an important aspect of climate
and can be used to grade climatic zones on a scale
of five: (1) Tropical, with annual and monthly
averages above 20° C (68° F); (2) Subtropical, with
4 to 11 months above 20° C, and the balance
between 10° and 20° C (50° to 68° F); (3)
Temperate, with 4 to 12 months at 10° to 20° C,
and the rest cooler; (4) Cold, with 1 to 4 months
at 10° to 20° C, and the rest cooler; and (5) Polar,
with 12 months below 10° C.

17. Within each hemisphere, eight basic
climatological zones can also be recognized
in terms of precipitation: (1) Equatorial: rain
in all seasons; (2) Tropical: summer rain with
winters dry; (3) Semi-arid Tropical: slight
summer rain; (4) Arid: dry in all seasons; (5)
Dry Mediterranean: slight winter rain; (6)
Mediterranean: winter rain, summers dry; (7)
Temperate: precipitation in all seasons; (8)
Polar: precipitation sparse in all seasons.

18. Precipitation
Map (Annual)

20. Vegetation classification
 Both of the above meteorological parameters
fail to meet the need for a true and universal
climatic description. Vegetation, however,
offers a useful guide, particularly in special
cases, such as the selva, or equatorial rainforest
belt, hot with tropical rain much of the year;
the savannah, warm-hot, with strong
seasonality; and the tundra, cold, with strong
seasonality.

21. Satellite Picture of El Niño

22. This image of the Pacific Ocean was taken by the French-
American satellite TOPEX/Poseidon on December 18,
1997. It shows the height of the sea surface—an indication
of the heat present in the waters—taking into account
normal conditions in the same area on December 10. The
volume and area of the warm zone is a manifestation of El
Niño, the unusually warm southward current that appears
in the region every three to seven years. In this image, the
red and white areas indicate unusual patterns of heat
storage. In the white zones, the marine surface is between
14 and 32 cm higher than normal, and is correspondingly
warmer; in the red zones it does not surpass 10 cm. The
green areas indicate normal conditions, while the purple
area in the western Pacific indicates a height of at least 18
cm below normal sea level.

23. It is a particularly helpful system for a person
who wants to know the nature of an area and
what it is like to live there. Because
temperature relates to precipitation in terms
of potential evaporation, a classification
based on the latter two provides an excellent
guide, with four fundamental divisions: hot-
dry (arid), cold-dry (polar or glacial), hot-wet
(selva), and moderate-warm to cool-humid
(temperate).

24. Indian climate
 Because of the peninsularity, unusual topography, and
geographical position of India, climatic conditions are
widely diversified, on both a seasonal and regional basis.
The diversity ranges from tropical to temperate zonal
extremes; the temperature extremes are confined largely
to the slopes of the Himalaya. Except in the more
mountainous regions, most of the rest of India has a
uniformly tropical climate. Seasonal variations, resulting
from the south-western and north-eastern monsoons,
profoundly influence temperature, humidity, and
precipitation throughout the subcontinent.

25. For general purposes, the seasons of India may be
classified as rainy and dry. The rainy season, which
generally extends from June to November, is the
season of the south-western monsoon, a moisture-
laden wind blowing off the Indian Ocean and the
Arabian Sea. Beginning early in June on the
western coast of the peninsula, the monsoon
gradually affects almost the entire country. During
this season, rainfall can be very heavy—along the
slopes of the Western Ghats it often reaches more
than 3,175 mm (125 in).

26. Cherrapunji in the Khasi Hills of north-eastern
India ranks as one of the wettest places on Earth—
the village received a record-breaking 22,987 mm
(905 in) of rain in 1861 and its average yearly
rainfall is about 10,920 mm (430 in). The nearby
village of Mawsynram holds the record of the
world’s highest average annual rainfall with 11,873
mm (467 in) a year. Mean annual precipitation
along the southern slopes of the Himalaya is about
1,525 mm (60 in).

27. The south-western monsoon fails at times, causing
droughts and occasionally famine. However, the
rains are a mixed blessing. They lead to the
proliferation of malaria-carrying mosquitoes, while
the contrast between day- and night-time
temperatures encourages respiratory disorders.
Normally, the power of the monsoon diminishes in
September. The cool season of the north-eastern
monsoon, extending from early December until
after the end of February, is usually accompanied
by extremely dry weather.

28. although severe storms, attended by slight
precipitation on the northern plains and
heavy snowfalls in the Himalaya, sometimes
cross the country. The hot season, beginning
about the middle of March and extending
until the onset of the south-western
monsoon, is most oppressive during May,
when temperatures as high as 51.7° C (125° F)
are not uncommon in central India.

29. In the vicinity of Kolkata, the mean annual
temperature is about 26.1° C (79° F). The mean
annual temperature in the west-central coastal
region of the peninsula is about 27.8° C (82° F).
Around Chennai (formerly Madras) temperatures
range between about 24.4° and 33.3° C (76° to 92°
F), with an annual mean of about 28.9° C (84° F).
Climate

30. Temperature
map of world
recorded in
January 2007
Temperature (January)
Microsoft ® Encarta ® 2007. © 1993-2006 Microsoft Corporation. All rights reserved.

32. Climatic map of
India and
neighboring
countries