Climatic Division

Introduction

Climate refers to the total of weather variations over the large area for a long period of time (more than thirty years). Weather refers to the atmospheric conditions for a shorter period of time.

The elements of weather and climate are the same, i.e. temperature, atmospheric pressure, wind, humidity and precipitation.

Weather conditions might fluctuate even within a day. For instance- Weather of Rajasthan in day and night. The climate of India is described as the 'monsoon' tropical type. In Asia, this type of climate is found mainly in the south and the southeast Asia

Factors Affecting Climate

There are six major determinants of the climate of any place. Namely- latitude, altitude, pressure and wind system, distance from the sea (continentality), ocean currents and relief features.

LATITUDE- The amount of solar energy received varies according to latitude due to tilting of earth on its axis. As a result, temperature of a place decreases from the equator towards the poles.

ALTITUDE- As one goes from the surface of the earth to higher altitudes, the density of the atmosphere and temperature decreases. The hill area are therefore cooler during summers. For instance- Hill stations such as Kullu, Manali etc, are most visited tourist spots during summers.

WIND AND PRESSURE- The pressure and wind system of any area depends upon the latitude and altitude of the place. Thus, it influences the temperature and rainfall pattern.

Upper Air Circulation: The upper air circulation over Indian landmass is due to Jet streams that has created weather differences. For instance- Westerly and Easterly jet streams in winters and summers season.

Tropical Cyclones and Western Disturbances: Tropical cyclones originates in the Bay of Bengal and Arabian Sea and the influence large parts of the coastal India

Most of the cyclones originate in the Bay of Bengal and influence the weather conditions during the southwest monsoon season (low intensity cyclones)

Climate Classfication

India is characterised by the tropical monsoon type of climate. However, due to the large latitudinal extent, the presence of Himalayas in the north, the India Ocean in the south have resulted in great differences in the distribution of temperature and precipitation in the India.

The climate of north like in Jammu and Kashmir is different from that of south like in Kanyakumari and so is the climate of east from that of the west. India is divided into a large number of climatic regions of small size.

A climatic region is that area having a broad uniformity of climatic conditions determined by the combined effects of climatic elements such as- temperature, pressure, winds, humidity and precipitation.

Temperature and rainfall are two important elements which are conducive in all the schemes of climatic classification. There are different schemes of classification of climate. Such as Koeppen and Thornthwaite

Koeppen has given his scheme of Climatic classification

on monthly values of temperature and precipitation.

On the above ground Koeppen have given five classification of climate. He used to capital letters of English alphabets to show his classification as follows;

A= Tropical climate

B= Dry climate

C= Warm climate

D= Snow climate

E= Ice climate

S= Steppe type climate or semi-arid

W= Arid climate

On the basis of seasonal distribution of temperature and rainfall the above five region are also classified in sub regions and to address them he used small letters of the English alphabets as;

A = Hot summer, average temperature of warmest month is more than 220 C.
C= Cool summer, average temperature of the warmest month is less than 220 C.
W = Dry in winter, rainfall in summer
H = Average annual temperature under 180 C
S= Dry in summer, rainfall in winter
M = Short dry season, monsoon type climate
F = no dry season, rainfall through out the year.
T = Tundra type climate
G = Ganga type climate, hottest month before summer solstice.

 

India's climate is divided into the following 9 climatic

Monsoon type with short dry season (Amw) — the western coastal belt lying south of Goa experiences this type of climate

Monsoon type with dry season in summers (AS) — the region of this type of climate found along the coromandel coast.

Tropical Savannah type (Aw) — covering the entire peninsular region except for some coastal parts experiences this type of climate

Semi-arid steppe climate (BShw) — this climatic region consists of the interior parts of the peninsular plateau and some parts of Gujarat, Rajasthan, Haryana, Punjab.

Hot desert type (BWhw) — this type of climate is found only in the western part of Rajasthan. The famous Thar desert

Monsoon type with dry winters (Cwg) —Indo-Gangetic plains of India experiences this type of climate.

Cold-humid winter type with short summer (Dfc) — this climate is characterized by a short summer season. This region is found in the north-eastern parts of India.

 

Polar type (E) — this type of climate is found in Jammu & Kashmir UT and Ladakh UT.