Elements of Climate
Delhi Police & SSC Exams
1. Introduction
The climate of any place is determined by several elements that describe the condition of the atmosphere. These elements together decide whether the region will be hot or cold, dry or wet, calm or stormy.
Key Elements:
- Temperature: Degree of hotness or coldness
- Pressure: Weight of air on Earth's surface
- Winds: Horizontal movement of air
- Humidity: Amount of water vapor in air
- Rainfall: Fall of water from clouds
Significance:
Determines regional climate patterns and influences human activities
Exam Trick: "TPWHR → Temperature, Pressure, Winds, Humidity, Rainfall"
2. Temperature
Basic Information:
- Definition: Degree of hotness or coldness of atmosphere
- Measurement: Thermometer
- Units: Celsius (°C) or Fahrenheit (°F)
- Importance: Influences air pressure, wind, and rainfall
Factors Affecting Temperature:
- Latitude: Near equator = hot; near poles = cold
- Altitude: Higher altitude = lower temperature
- Distance from sea: Sea moderates temperature
- Ocean currents: Warm/cold currents affect temperature
- Winds: Warm or cold winds modify temperature
Temperature Lapse Rate:
Earth Surface
↑
15°C
↑
10°C
↑
5°C
↑
0°C
↑
-5°C
↓
Troposphere (Temp decreases with height)
Lapse Rate: 1°C decrease per 165 meters (approx.)
Exam Trick: "LADOW = Latitude, Altitude, Distance, Ocean, Winds"
3. Atmospheric Pressure
Basic Information:
- Definition: Weight of the air exerted on Earth's surface
- Measurement: Barometer
- Units: Millibar (mb) or Hectopascal (hPa)
- Pattern: Decreases with height
Pressure Zones:
| Zone Type | Latitude Range | Example |
|---|---|---|
| Equatorial Low | 0°–5° N & S | Rising air → Low pressure |
| Subtropical High | 30° N & S | Descending air → High pressure |
| Subpolar Low | 60° N & S | Low pressure belts |
| Polar High | 90° N & S | Very cold, high pressure |
Exam Trick: "Low → High → Low → High (from Equator to Pole)"
4. Winds
Basic Information:
- Definition: Horizontal movement of air from high to low pressure
- Speed Measurement: Anemometer
- Direction Measurement: Wind Vane
- Function: Moves air masses and moisture
Types of Winds:
| Type | Description | Example |
|---|---|---|
| Permanent Winds | Blow throughout the year in one direction | Trade Winds, Westerlies |
| Seasonal Winds | Change direction with season | Monsoon Winds (India) |
| Local Winds | Blow in small areas for short time | Land Breeze, Sea Breeze |
Exam Trick: "PSL → Permanent, Seasonal, Local"
5. Humidity
Basic Information:
- Definition: Amount of water vapor present in the air
- Measurement: Hygrometer
- Indication: How "wet" or "dry" atmosphere feels
- Effect: Influences comfort and evaporation
Types of Humidity:
Absolute Humidity
Actual amount of water vapor in air (g/m³)
Relative Humidity
Ratio of water vapor to maximum possible amount (%)
Effects: High humidity → discomfort, sweating | Low humidity → dry air, increased evaporation
Exam Trick: "Absolute = Actual, Relative = Ratio"
6. Rainfall
Basic Information:
- Definition: Fall of water from clouds (rain, snow, hail, sleet)
- Measurement: Rain Gauge
- Forms: Rain, snow, hail, sleet
- Importance: Source of freshwater for all life
Types of Rainfall:
| Type | Cause | Example |
|---|---|---|
| Convectional | Due to heating of air at surface | Equatorial regions |
| Orographic | Due to air rising over mountains | Western Ghats (India) |
| Cyclonic | When warm and cold air masses meet | Temperate regions |
Exam Trick: "C.O.C = Convectional, Orographic, Cyclonic"
7. Interconnection Between Elements
Temperature
Pressure
Wind
Humidity
Rainfall
All five elements are interrelated and influence each other
8. Quick Summary Chart
| Element | Measured by | Unit | Example Effect |
|---|---|---|---|
| Temperature | Thermometer | °C / °F | Affects seasons |
| Pressure | Barometer | Millibar (mb) | Causes wind formation |
| Winds | Anemometer/Vane | km/h or m/s | Moves air & moisture |
| Humidity | Hygrometer | % | Causes sweat / discomfort |
| Rainfall | Rain Gauge | mm | Source of water, affects crops |
PYQs (Delhi Police, SSC & State Exams)
Which instrument is used to measure air pressure?
Options: (a) Thermometer (b) Barometer (c) Hygrometer (d) Anemometer
Category: Measurement Instruments
Show Answer
Barometer
Which type of rainfall occurs when warm moist air rises over mountains?
Options: (a) Convectional (b) Cyclonic (c) Orographic (d) None
Category: Rainfall Types
Show Answer
Orographic
Which of the following is a permanent wind?
Options: (a) Monsoon (b) Land Breeze (c) Trade Wind (d) Sea Breeze
Category: Wind Types
Show Answer
Trade Wind
Relative humidity is measured by —
Options: (a) Thermometer (b) Rain Gauge (c) Hygrometer (d) Barometer
Category: Measurement Instruments
Show Answer
Hygrometer
Final Exam Tips
TPWHR = Temperature, Pressure, Winds, Humidity,
Rainfall
Thermometer → Temperature
Barometer → Pressure
Anemometer/Wind Vane → Wind
Hygrometer → Humidity
Rain Gauge → Rainfall
Lapse Rate = 1°C per 165 m
Orographic rainfall = On windward side of
mountains
Memory Trick: "Tiny People Wear Happy Raincoats" →
Temperature, Pressure, Wind, Humidity, Rainfall
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