NDA & CDS 1 2026 Exam Geography – Climatology (Class 1)

Climatology is an essential branch of Physical Geography that deals with the study of the Earth’s atmosphere, weather patterns, and climatic processes over time. For aspirants preparing for the NDA and CDS 1 2026 Exam, understanding climatology helps build a strong foundation for both conceptual clarity and objective-type questions in the General Knowledge paper.

NDA & CDS 1 2026 Exam Geography – Climatology (Class 1)

What is Climatology?

Climatology is the scientific study of climate, which includes the long-term patterns of temperature, humidity, wind, and precipitation in a particular region. It differs from meteorology, which studies short-term weather conditions.

In simple terms:

• Weather = Short-term atmospheric conditions.
• Climate = Average weather conditions over a long period (usually 30 years or more).

Importance of Climatology in Geography

1. Helps understand global weather systems and their impact on human life.
2. Aids in studying agriculture, vegetation, and settlement patterns.
3. Crucial for understanding natural disasters like cyclones, droughts, and floods.
4. Plays a role in defence planning, especially in operations conducted in extreme climates.

Structure of the Atmosphere

The atmosphere is divided into five main layers based on temperature variation:

Composition of the Atmosphere

The atmosphere is primarily made up of:

• Nitrogen (78%)
• Oxygen (21%)
• Argon (0.93%)
• Carbon dioxide (0.04%)
• Traces of gases like neon, helium, hydrogen, and ozone.

Elements of Climate

1. Temperature – The degree of hotness or coldness of the air.
2. Pressure – The weight of the air exerted on the Earth’s surface.
3. Wind – Movement of air from high to low pressure areas.
4. Humidity – The amount of water vapour in the air.
5. Precipitation – All forms of water that fall from the atmosphere, like rain, snow, and hail.

Factors Affecting Climate

1. Latitude – Determines the angle of sunlight; affects temperature.
2. Altitude – Higher altitude = lower temperature.
3. Distance from Sea – Coastal areas have moderate climates; interiors have extremes.
4. Ocean Currents – Warm and cold currents influence temperature and rainfall.
5. Winds – Carry heat and moisture, affecting regional climates.
6. Relief Features – Mountains block or direct winds, causing rainfall or dry conditions.

Types of Climate

According to Köppen’s Classification, the world’s climate is divided into:

1. Tropical Climate (A) – Hot and humid, near the equator.
2. Dry Climate (B) – Deserts and semi-arid regions.
3. Temperate Climate (C) – Moderate, found in mid-latitudes.
4. Cold Climate (D) – Found in high latitudes.
5. Polar Climate (E) – Extremely cold, near the poles.

Climatology and Defence Relevance

For defence aspirants, understanding climatology helps in:

• Analyzing terrain conditions during operations.
• Planning movements in desert, mountainous, or snow-covered regions.
• Interpreting weather maps and satellite data for strategy and logistics.

Key Points to Remember for NDA/CDS Exam

• The troposphere is the most important layer for weather study.
• The Coriolis Effect causes winds to deflect due to Earth’s rotation.
• The Ozone layer in the stratosphere protects Earth from harmful UV rays.
• Monsoon winds are a vital part of India’s climatic system.
• Global Warming and Greenhouse Effect are current environmental concerns.

Conclusion

Climatology forms the backbone of physical geography. For NDA and CDS aspirants, mastering this topic not only strengthens general awareness but also enhances understanding of how natural systems interact with human and defence activities. The next classes in this series will delve deeper into temperature distribution, pressure belts, wind systems, and rainfall mechanisms.