Atmosphere Winds and Climate Important Notes with MCQs -

Geography Series – Part 13

Atmosphere, Winds and Climate Complete Notes for BPSC, UPSC & Competitive Exams

Series Name: Geography Series ( Atmosphere Winds and Climate )
Part Number: 13
Current Topic: Atmosphere, Winds & Climate
Previous Topic: Volcano and Earthquake
Next Topic: Indian Rivers

Table of Contents ( Atmosphere Winds and Climate )

Introduction to Atmosphere
Composition of Atmosphere
Structure of Atmosphere
Importance of Atmosphere
Weather and Climate
Elements of Weather and Climate
Insolation and Heat Budget
Temperature Distribution
Atmospheric Pressure
Winds
Types of Winds
Planetary Winds
Periodic Winds
Local Winds
Cyclones and Anticyclones
Humidity
Clouds and Precipitation
Climate and Climatic Factors
Köppen Climate Classification
Indian Climate
Climate Change and Global Warming
Key Points for BPSC
Previous Year Questions (PYQ)
HOTS Questions
Important MCQs
Expected Questions and Answers
Conclusion

Introduction | परिचय ( Atmosphere Winds and Climate )

The atmosphere is a layer of gases around the Earth. It protects us from harmful solar rays. That helps to maintain temperature. It also provides the gases needed for life.

हिंदी में:
वायुमंडल पृथ्वी के चारों ओर गैसों का आवरण है। यह सूर्य की हानिकारक किरणों से रक्षा करता है तथा जीवन के लिए आवश्यक गैसें उपलब्ध कराता है।

Abbreviations ( Atmosphere Winds and Climate )

Abbreviation	Full Form
O₃	Ozone
CO₂	Carbon Dioxide
UV	Ultraviolet
ITCZ	Inter Tropical Convergence Zone
ELR	Environmental Lapse Rate
GHG	Greenhouse Gas
ENSO	El Niño Southern Oscillation
IMD	India Meteorological Department

What is Atmosphere?

Atmosphere is the gaseous envelope surrounding the Earth.

Composition of Atmosphere

Gas	Percentage
Nitrogen	78%
Oxygen	21%
Argon	0.93%
Carbon Dioxide	0.04%
Others	Trace Amount

Key Facts

Nitrogen is the most abundant gas.
Oxygen supports life and combustion.
Plants use carbon dioxide to make food.
Ozone absorbs UV rays.

Structure of Atmosphere

1. Troposphere

Height: 8–18 km
All weather activities like rain, clouds and storms occur here.
Contains 75% of atmospheric gases.

Important Fact

Temperature decreases by 6.5°C per 1000 m.

2. Stratosphere

18–50 km
Ozone layer present.
Aircraft fly here.

3. Mesosphere

50–80 km
Meteors burn here.

4. Thermosphere

80–700 km
Contains ionosphere.
Radio communication possible.

5. Exosphere

Uppermost layer.
Merges into outer space.

Importance of Atmosphere ( Atmosphere Winds and Climate )

Atmosphere Helps In

Breathing
Weather formation
Protection from meteorites
Water cycle
Maintaining temperature

Weather and Climate ( Atmosphere Winds and Climate )

Weather	Climate
Short-term condition	Long-term average condition
Changes daily	Changes over years
Local phenomenon	Regional phenomenon

Example

Today’s rain = Weather

Average rainfall of Bihar = Climate

Elements of Weather and Climate

Temperature
Pressure
Wind
Humidity
Rainfall
Cloud Cover

Insolation

Definition

Insolation means the solar energy received by the Earth. It is the main source of heat and light on our planet.

Factors Affecting Insolation

Latitude
Duration of daylight
Cloud cover
Altitude

Heat Budget of Earth

100 units solar energy received:

35 reflected
14 absorbed by atmosphere
51 absorbed by Earth

This balance is called Heat Budget.

Temperature Distribution

Horizontal Distribution

Affected by:

Latitude
Ocean currents
Land-water contrast

Vertical Distribution

Temperature decreases with altitude.

Lapse Rate

Normal lapse rate = 6.5°C per 1000 m

Atmospheric Pressure

Pressure exerted by air on Earth surface.

Instrument

Barometer

Unit

Millibar (mb)

Pressure Belts of Earth

Equatorial Low Pressure Belt
Subtropical High Pressure Belt
Subpolar Low Pressure Belt
Polar High Pressure Belt

Winds ( Atmosphere Winds and Climate )

Wind is moving air. It always moves from a high-pressure area to a low-pressure area.

Factors Affecting Winds

Pressure Gradient
Coriolis Force
Friction

Types of Winds

1. Planetary Winds

Trade Winds

Blow from subtropical highs to equatorial low.
Northeast Trade Winds (Northern Hemisphere)

Westerlies

Blow west to east.
Important for Europe.

Polar Easterlies

Blow from polar high pressure.

2. Periodic Winds

Monsoon Winds

Seasonal reversal of winds.

Land Breeze

Night time:
Land → Sea

Sea Breeze

Day time:
Sea → Land

3. Local Winds

Loo

Hot dry wind
Northern India
Summer season

Chinook

Rocky Mountains

Foehn

Alps

Mistral

France

Sirocco

Sahara to Mediterranean

Cyclones and Anticyclones

Cyclone

Low pressure center
Air converges inward
Associated with rain

Examples

Amphan
Fani
Yaas

Anticyclone

High pressure center
Air diverges outward
Clear weather

Humidity

Amount of water vapor in air.

Types

Absolute Humidity
Relative Humidity
Specific Humidity

Clouds

Condensation of water vapor.

Major Cloud Types

Cirrus

High altitude

Cumulus

Cotton-like

Stratus

Layered clouds

Nimbus

Rain-bearing clouds

Precipitation

Water falling from atmosphere.

Types

Rainfall
Snowfall
Hail
Sleet

Types of Rainfall ( Atmosphere Winds and Climate )

Convectional Rainfall

Equatorial regions

Orographic Rainfall

Mountain barriers

Example:
Western Ghats

Cyclonic Rainfall

Associated with cyclones

Climate

Average weather condition over a long period.

Factors Affecting Climate

Latitude

Higher latitude = Lower temperature

Altitude

Higher altitude = Cooler climate

Distance from Sea

Moderates climate

Ocean Currents

Warm and cold currents affect temperature

Relief

Mountains influence rainfall

Köppen Climate Classification

Type	Climate
A	Tropical
B	Dry
C	Warm Temperate
D	Cold
E	Polar

Indian Climate

Characteristics

Monsoonal climate
Seasonal reversal of winds
Uneven rainfall

Seasons of India

Winter

December–February

Summer

March–May

Southwest Monsoon

June–September

Retreating Monsoon

October–November

Climate Change

Climate change means long-term changes in temperature, rainfall and weather conditions across the world.

Global Warming

Global warming is the gradual increase in Earth’s temperature. It happens mainly because of greenhouse gases released by human activities.

Major Greenhouse Gases

CO₂
Methane
Nitrous Oxide
Water Vapor

Effects of Global Warming

Glacier melting
Sea level rise
Extreme weather events
Biodiversity loss

Key Points for BPSC Examination

Troposphere contains weather phenomena.

Ozone layer lies in Stratosphere.

Loo blows in North India.

Trade Winds blow toward Equator.

Normal lapse rate = 6.5°C/1000m.

Cyclone = Low pressure center.

Anticyclone = High pressure center

Monsoon is a periodic wind.

Köppen classified climate into five major groups.

Indian climate is monsoonal.

Previous Year Questions (PYQ)

Q1. Ozone layer is located in which layer?

A. Troposphere
B. Stratosphere
C. Mesosphere
D. Thermosphere

Answer: B

Q2. Loo is a:

A. Cold wind
B. Local hot wind
C. Trade wind
D. Polar wind

Answer: B

Q3. Weather phenomena occur in:

A. Stratosphere
B. Troposphere
C. Mesosphere
D. Exosphere

Answer: B

Q4. Instrument measuring pressure?

A. Hygrometer
B. Thermometer
C. Barometer
D. Rain Gauge

Answer: C

Q5. Which layer contains ozone?

A. Troposphere
B. Stratosphere
C. Thermosphere
D. Exosphere

Answer: B

HOTS Questions

1. Why are aircraft generally flown in the stratosphere?

Answer: Due to stable weather conditions and absence of clouds.

2. Why is Chennai wetter in winter than Delhi?

Answer: Due to retreating monsoon winds from Bay of Bengal.

3. Why does temperature decrease with altitude?

Answer: Atmosphere is heated from Earth’s surface, so temperature decreases upward.

4. Explain the role of ozone layer.

Answer: Absorbs harmful ultraviolet radiation.

5. Why does Rajasthan experience extreme temperatures?

Answer: Continental location and low humidity.

Important MCQs

1. Most abundant atmospheric gas?

A. Oxygen
B. Nitrogen
C. Argon
D. CO₂

Answer: B

2. Trade winds blow toward:

A. Poles
B. Equator
C. Tropics
D. Mountains

Answer: B

3. Which cloud gives rainfall?

A. Cirrus
B. Nimbus
C. Cumulus
D. Stratus

Answer: B

4. Normal lapse rate is:

A. 3°C
B. 4°C
C. 5°C
D. 6.5°C

Answer: D

5. Hot local wind of North India:

A. Chinook
B. Mistral
C. Loo
D. Foehn

Answer: C

6. Cyclone represents:

A. High pressure
B. Low pressure
C. Neutral pressure
D. None

Answer: B

7. Humidity is measured by:

A. Hygrometer
B. Barometer
C. Thermometer
D. Anemometer

Answer: A

8. Monsoon winds are:

A. Planetary winds
B. Local winds
C. Periodic winds
D. Polar winds

Answer: C

9. Ozone absorbs:

A. Infrared rays
B. UV rays
C. Radio waves
D. X-rays

Answer: B

10. Which rainfall occurs due to mountains?

A. Cyclonic
B. Convectional
C. Orographic
D. Frontal

Answer: C

Expected Questions and Answers (BPSC 2026)

Q1. Describe the structure of atmosphere.

Answer: Atmosphere consists of Troposphere, Stratosphere, Mesosphere, Thermosphere and Exosphere with distinct characteristics.

Q2. Explain planetary winds.

Answer: Permanent winds including Trade Winds, Westerlies and Polar Easterlies that blow throughout the year.

Q3. Differentiate weather and climate.

Answer: Weather is short-term atmospheric condition while climate is long-term average weather pattern.

Q4. What are pressure belts?

Answer: Zones of high and low atmospheric pressure distributed from equator to poles.

Q5. Discuss the causes of global warming.

Answer: Excess greenhouse gases from industries, vehicles, deforestation and fossil fuel burning.

Exam-Oriented Revision Sheet

Remember These 10 Facts

Nitrogen = 78%
Oxygen = 21%
Ozone Layer → Stratosphere
Weather → Troposphere
Lapse Rate = 6.5°C/1000m
Loo → North India
Monsoon → Periodic Wind
Cyclone → Low Pressure
Anticyclone → High Pressure
India → Tropical Monsoon Climate

Conclusion

Atmosphere, winds and climate are important topics in Geography. These concepts help us understand weather, rainfall, monsoons and climate change. Questions from this chapter are frequently asked in BPSC, UPSC, SSC and Railway exams. Therefore, students should revise atmospheric layers, pressure belts, winds and Indian climate regularly for better exam performance.

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Geography Series – Part 13 🌍📚