LEARNING OBJECTIVES
This lesson will help you to: -
- study about the reasons behind the changing weather.
- learn about different seasons in our country.
- study about wind and air currents.
Real Life Examples
- India is one of the highest flood prone countries in the world coastal areas and the states close to the seas or rivers are more prone to get flooded. In recent past, Assam and Jammu and Kashmir have faced severe floods due to high level of rainfall.
Amazing facts
- The highest temperature ever recorded in Antarctica is 14.6°C, recorded on January 5, 1974.
- The Met Office uses a super-computer- one of the fastest in the world – to help make its weather forecasts. Its newest machine has as much computing power as 20,000 normal PCs.
- The South Pole is the least sunny place-only 182 days a year get sunshine.
QUICK CONCEPT REVIEW
Temperature
- It is the measure of how hot or how cold the day is.
- It is measured in Celsius.
- The temperature of the environment varies from place to place and depends on various factors.
- Maximum temperature is the hottest/highest
- Temperature noted in the day and minimum temperature is the coldest/ lowest temperature noted in the day.
Weather
- The state of the atmosphere at a place and time with regard to heat, cloudiness, dryness, sunshine, wind, rain, etc.
- Weather can be changed by sun, rain, clouds and wind.
Sun
- Sun gives us solar energy that is a renewable source, It also gives us heat and light.
- The heat of the sun keeps the Earth warm.
- The sun rises in the early morning and sets in the evening. As the sun rises, the temperature starts to rise and in the afternoon, maximum temperature of the day can be recorded. As the sun sets, the sun disappears and thus the temperature also decreases.
- The sun also plays a crucial role in the water cycle as it helps in evaporation of water from the surface of Earth, which eventually comes down as rain.
Rain
- Rain is very important for cooling down the temperature of the Earth.
- Rains are also very important for the farmers as the plants get water.
- Excess of rains causes a lot of damage and also causes floods.
- Cherrapunji in India receives the highest rainfall.
Clouds
- Clouds are a visible mass of condensed water vapour floating in the atmosphere, typically high above the ground.
- There are 4 types of clouds viz. cirrus clouds, cumulus clouds, stratus clouds and nimbus clouds.
- Some clouds carry water vapour which bursts to rainfall.
Wind
- Moving air is called wind.
- The hot air that blows in summers in north India is called loo. It is bad for health and one should avoid going out during summer afternoons.
- During the spring season, the wind is light flowy and breezy. The weather becomes pleasant and comfortable.
Seasons
- When certain weather persists in a large area for a long period of time it is called season.
- There are 5 seasons. These are viz. spring, summer, monsoons or rainy season, autumn and winter.
Historical Preview
- Ritu means “season” in the Hindu calendar, and there are six ritus or Indian seasons. The word is derived from the vedic Sanskrit word Ritu, a fixed or appointed time. The 6 ritus in the Hindu calendar are Vasanta (spring), Grishma (summer), Varsha (Monsoon), Sharad (Autumn), Hemant (winter), Shishir (Fall).
Misconcept/ Concept
Misconcept: we experience seasons because of the Earth’s changing distance from the sun.
Concept: Earth’s orbit around the sun in an elliptical path.
Misconcept: That the sun rises exactly in the east and sets exactly in the west every day.
Concept: The sun rises in the southeast in winter and northeast in winter and northeast in winter and northeast in summer, and sets in the southwest in winter and northeast in summer, and sets in the southwest in winter and northwest in summer.
Spring
- It is a season when flowers bloom in abundance.
- The weather is pleasant with light breeze
Summer
- The weather in this season is extremely hot.
- Days are longer than nights in summers.
- People prefer to stay indoors in air conditioners and drink a lot of cold beverages.
- Mango, litchis, cherries, melons and watermelons are some summer fruits that are cooling in nature.
- Usually light cotton clothes are worn in this season.
- In India, this season is at its peak in May-June.
Rainy Season or Monsoons
- This season comes after summers.
- In India, this season comes in July-August.
- Raincoats, Plastic footwear and umbrellas come handy in this season.
- During this season, the temperature comes down and there is some relief from the hot scorching heat of summers. This season is very humid.
Autumn
- In this season weather starts to get cooler.
- In this season night and days become equal.
- Leaves start to change colour and fall off the trees.
- October-November marks this season in India.
Winters
- This is the cold season.
- In India, this season comes in December- January.
- Chilly wind blows during this season.
- The nights are longer and the days are shorter in winters.
- Hot beverages like tea, coffee are preferred during winter. Woollen clothing like sweaters, jackets, coats and mufflers are worn in winters.
