RBSE Class 11 Geography Notes Chapter 16 Classification of Climate

Go through these RBSE Class 11 Geography Notes Chapter 16 Classification of Climate contain important concepts so that students can score better marks in the exam.

Rajasthan Board RBSE Class 11 Geography Notes Chapter 16 Classification of Climate

Season and Climate

• Season is the sum of short-term conditions of the atmosphere in context of the components of weather in a particular duration of time at a place.
• Climate is the average condition of the weather of a particular place; or climate is the sum of the long-term weather conditions of a particular place.

Classification of Climate

• The factors which affect the climate include condition of latitudes, distance from sea coast, mountain barriers, oceanic currents, direction of the winds, height from sea level and turbulence.
• The world’s first attempt to classify the climate was done by the Greeks.
• On the basis of the temperature, the world is classified into three zones- tropical zone, temperate zone and frigid zone.
• Many scholars in the world have classified the climate and the major among them are Koppen, Miller, Thornthwaite and Trewartha.
• Climate has a deep impact on all the physical and mental activities of the humans.

Classification of Climate According to Koppen

• The famous German Climatologist, Vladimir Koppen, first presented the classification of climate in 1900. The basis of this classification was the vegetation region of the world.
• He considered temperature, rainfall and their seasonal nature as the basis of his classification.
• Koppen classified the climate into five major types, for which he used the letters A, B, C, D, E.
• He used the letter A to symbolise Tropical Wet Climate, B for Dry Climate, C for Mild, Humid Climate, D for Snowy Forest Temperate and E for Polar Climate.
• Tropical Wet Climate is further classified into Tropical Monsoon, Tropical Wet Climate and Tropical Wet and Dry Climate.
• Dry Climate is further classified into Tropical Steppe Climate, Cold Steppe Climate, Tropical Desert Climate and Cold Tropical Desert Climate.
• Mild, Humid Climate is further classified into Rainfall throughout the year (Cf) Extreme rainfall in summer season (Cw) and More rainfall in winter season (Cs).
• Cold Temperate Climate is also called Snowy Climate. In this, the temperature of the warmest month is nearly 10 degree Celsius, and that of the coldest month is nearly -3 degree Celsius.
• In Polar Climate, the temperature of the warmest month is less than 10 degree Celsius. There is no summer season in this. Polar climate is further classified into Tundra Climate (ET) and Continuous Glacial Climate (EF).

Green House Effect

• Gases found in the atmosphere like carbon-dioxide, water vapour, methane, nitrous-oxide, chloro-fluoro-carbons, etc. are responsible for the greenhouse effect on the earth.
• These gases allow the short-wave radiations from the sun to enter into the earth, but prevent the radiation of long waves from the earth and makes them return to the earth, due to which the earth’s surface is getting warmer. This effect is called the Greenhouse Effect.
• The amount of carbon-dioxide is continuously increasing in the atmosphere.
• In extreme cold regions, when there is no insolation in winters, there greenhouse effect is especially used to grow plants of fruits and vegetables.
• Along with rapid industrialisation and vehiclular pollution, the increasing use of mineral oil, burning, of fire wood for domestic purpose, volcanic eruption, breathing process of creatures, all are responsible for the increase of carbon dioxide.
• In the greenhouse effect, carbon-dioxide contributes 57%, methane contributes 18%, nitrous-oxide contributes 6% and chloro-fluoro-carbons contribute 17%.
• There are negative effects of the greenhouse effect, which include increase in temperature, increase in rainfall, melting of snow on the poles, rise in the water level of the sea, adverse effects on agriculture, vegetation and living organisms.
• Greenhouse effect can be controlled by the expansion of forests, population control, use of organic fertilisers, use of non-conventional energy sources and by reducing the use of chloro-fluoro-carbons.

Global Warming

• Increasing the average temperature of the earth due to increase in greenhouse gases is called Global Warming.
• Due to being heavy, the carbon-dioxide gas accumulates in the form of a layer in the lower layer of the atmosphere near the earth’s surface. Due to the formation of this layer of gas, the thermal radiation from the earth which allows it to cool down at night time is blocked, and sent back to the earth. As a result, the temperature on the earth increases.
• According to National Science Academy, United States of America, there is a possibility of rise in the water-level of oceans by up to 1.5 meters by the end of this century.
• More than 200 million people world wide are likely to be affected by global warming.
• Negative effects are occurring due to global warming, like climatic change, increase in temperature of earth, El-Nino effect, melting of the glaciers, due to which the survival of living organisms is in danger.

Climatic Change

• The average seasonal condition of a place is called the Climate. When changes occur in these average seasonal conditions, then it is called Climatic Change.
• Climates have been changing on the earth since the very beginning.
• Systematic study of the climate started after the invention of barometer and thermometer in the year 1640 and rain gauge in the year 1676.
• At present, the nature of climatic change on the earth can be seen in the form of increase in the average temperature of the earth, increase amount in rainfall on earth, change in regional distribution of rainfall, melting of glaciers, rise in water-level of oceans and change in the seasonal cycle on the earth.

Classification of Climate Notes Important Terms

→ Turbulence or Disturbance: Violent and unsteady flow or motion of air or water in which minor swirls are produced.

→ Zones: Regions present between two latitudes on the surface are called zones. These are regions with almost identical characteristics, whose length is much greater than the width.

→ Torrid/Tropical Zone: The part of the earth’s surface between the Tropic of Cancer and the Tropic of Capricorn, characterised by a hot climate. In every section located in this zone, the sunrays fall vertically at. least once in a year.

→ Temperate Zone: The zone located between the Tropical Zone and the Frigid Zone on the earth.

→ Frigid Zone: The regions included in the Arctic Circle and the Antarctic Circle where the land remains covered with snow during a greater part of the year due to extremely low temperatures.

→ Tropical Wet Climate: Climate found in the nearby regions of Equator where high temperature and high rainfall conditions are seen throughout the year. Rainfall occurs due to high rate of evaporation over here.

→ Dry Climate: Evaporation is more than rainfall in this type of climate. High temperature and lack of water is found in this.

→ Polar Climate: Extremely cold climate found all around the North Pole and the South Pole where temperature is usually below the freezing point (0 degree Celsius) and the j-egion remains frozen almost whole the year.

→ Evaporation: A process by which a substance is converted from liquid into vapour state.

→ Range of Temperature: The difference between the highest and the lowest temperatures of a place. The range of temperature can be recorded on a daily, monthly or annual basis.

→ Savana Climate: The sub-type of the tropical wet climate where winter is dry and high temperature is found whole the year.

→ Steppe Zone: They are also known as semi-arid regions where thorn vegetation is primarily found.

→ Tundra Climate: Tundras are the Earth’s coldest, harshest biomes. Tundra ecosystems are treeless regions found in the Arctic and on the tops of mountains, where the climate is cold and windy and rainfall is scant.

→ Climatic Zones: The zones or regions in which similarity is found in climatic conditions (temperature, rainfall, humidity, etc.) are called Climatic Zones. Four large climatic zones or regions are found on the earth’s surface : Tropical Zone, Sub-Tropical Zone, Temperate Zone, Frigid Zone and Polar Region.

→ Greenhouse Effect: The trapping of the sun’s warmth in a planet’s lower atmosphere, due to the greater transparency of the atmosphere to visible radiation from the sun as compared to infrared radiation emitted from the planet’s surface.

→ Insolation: Energy obtained from the sun is called insolation. Polar regions get only 40% of the insolation compared to the Equator.

→ Radiation: The process by which an object or body emits radiation energy in the form of heat. This leads to loss in the heat of object and it gets cooled down.

→ Seismic Wave: A wave of energy that is generated by an earthquake or other vibration of the Earth, and that travels within the earth or along its surface. This wave first reaches the Epicentre.

→ Water Vapour: Water present in the atmosphere in the form of vapour.

→ Greenhouse Gas: A gas that contributes to the greenhouse effect by absorbing infrared radiation. Carbon-dioxide and chloro-fluoro-carbons are examples of greenhouse gases.

→ Industrialisation: Process of the development of manufacturing industries through technical development and mechanisation, as a result of which, there is a faster development of secondary and tertiary sectors as compared to the primary sector.

→ Mineral Oil: Nature-made hydrocarbons which are present in liquid form in porous rocks in the earth’s crust. It is a fossil fuel which is formed by the chemical process of animal remains in geological eras.

→ Volcano: A mountain or hill, typically conical, having a crater or vent through which hot and fluid lava, rock fragments, hot vapour, gas, ashes, water, etc. erupt from the earth’s crust.

→ Mining: Extraction of underground minerals, metals, and metallic and non-metallic minerals from relatively more depth inside the earth.

→ Fossil Fuel: Fossil fuels are sources of energy that are formed from the accumulated remains of plants and living organisms that were buried millions of years ago. Pressure, heat and time allow the organic matter to transform into one of the three major types of fossil fuels, which are coal, petroleum and natural gas.

→ Chemical Fertilizer: Chemical substances used for increasing the fertility of land, and growing more grain, fruits, flowers and vegetables.

→ Bio Fertilizer: This increases the productivity of crops and is produced from biological components.

→ Coral: A small sea creature which develops in a group mainly in tropical shallow sea water. The nature of coral depends on lime substances.

→ Season: Each of the four divisions of the year (spring, summer, autumn and winter) marked by particular weather patterns and daylight hours, resulting from the earth’s changing position in context to the sun in its annual solar orbit.

→ Glacier: A slowly moving mass of ice leading from top to downwards on a fixed path along the slope of land due to gravitational force. It is formed due to the accumulation and condensation of extreme amount of snow whose density is lower than that of water.

→ Climate Change: Long-term change in the climatic conditions of an extensive region.

→ Deposit: Accumulation of relatively small substances, rock fragments and sediments at a place.

→ Fossil: The remains or impression of a prehistoric plant or animal embedded in rock and preserved in petrified form is called Fossil. Fossils are found usually in sedimentary rocks.

→ Tropic of Cancer: 23$$\frac{1}{2}$$ degree North Latitude Circle. This is the last boundary of the sun’s vertical position in the Northern Hemisphere, to the north of which the sunrays never get vertical.

→ Tropic of Capricorn: 23$$\frac{1}{2}$$ degree South Latitude Circle. This is the southern boundary, to the south of which the sunrays never get vertical.