GEO • SHS 1Term 2WAEC / WASSCE SyllabusVIP Lesson
Weather, Climate and Climate Classification
Elements of weather and instruments, factors controlling climate, air masses in West Africa (cT vs. mT), the ITCZ, and the Köppen system.
Share Lesson with Students:
Real-World Context & Relevance in Ghana
During December to February, the Harmattan winds shroud Accra and northern Ghana in dusty haze, causing respiratory ailments and flight delays.
Key Syllabus Learning Objectives
- 1Differentiate between weather and climate and list standard meteorological instruments
- 2Analyze the dual roles of the Southwest Monsoons and Northeast Trades in West Africa
- 3Explain the seasonal movement of the ITCZ and its impact on rainfall regimes in Ghana
1
Comprehensive Syllabus Study Notes
• Weather vs. Climate: Weather is the day-to-day atmospheric conditions of a place; Climate is the average weather conditions over a long period (at least 30–35 years).
• Elements & Instruments: Temperature (Stevenson screen, Six's thermometer), Atmospheric pressure (Barometer), Wind speed (Anemometer), Wind direction (Wind vane), Rainfall (Rain gauge), Relative humidity (Hygrometer).
• West African Air Masses & Rainfall:
- Tropical Maritime (mT) Air Mass: Originates over the South Atlantic Ocean; warm, moist, southwest winds bringing rainy seasons.
- Tropical Continental (cT) Air Mass: Originates over the Sahara Desert; dry, dusty, northeast trade winds bringing the dry Harmattan season.
- Inter-Tropical Convergence Zone (ITCZ): Low-pressure belt where mT and cT air masses meet. Its north-south migration dictates the wet and dry seasons across West Africa.
- Weather vs. Climate: Weather is the day-to-day atmospheric conditions of a place; Climate is the average weather conditions over a long period (at least 30–35 years).
- Elements & Instruments: Temperature (Stevenson screen, Six's thermometer), Atmospheric pressure (Barometer), Wind speed (Anemometer), Wind direction (Wind vane), Rainfall (Rain gauge), Relative humidity (Hygrometer).
- West African Air Masses & Rainfall:
- Tropical Maritime (mT) Air Mass: Originates over the South Atlantic Ocean; warm, moist, southwest winds bringing rainy seasons.
- Tropical Continental (cT) Air Mass: Originates over the Sahara Desert; dry, dusty, northeast trade winds bringing the dry Harmattan season.
- Inter-Tropical Convergence Zone (ITCZ): Low-pressure belt where mT and cT air masses meet. Its north-south migration dictates the wet and dry seasons across West Africa.
Practical Example:
During December to February, the Harmattan winds shroud Accra and northern Ghana in dusty haze, causing respiratory ailments and flight delays.
Core Takeaway:
In WASSCE climate graphs, rainfall is plotted as vertical bars (histograms) while temperature is plotted as a smooth continuous line.
WAEC / WASSCE Examiner Tips
- In WASSCE climate graphs, rainfall is plotted as vertical bars (histograms) while temperature is plotted as a smooth continuous line.
Common Candidate Pitfalls & Errors to Avoid
- Answering a weather question with climate material, or vice versa, instead of separating the short state of the atmosphere from the long average.
- Adding twelve monthly means and reporting the total as the annual mean temperature.
- Reporting the annual temperature range as the highest monthly temperature.
- Saying temperature rises with height, so the lapse rate is applied in the wrong direction on a hill station.
- Treating relative humidity as the amount of water in the air, when it is a percentage of what that temperature could hold.
- Applying the lapse rate to the height above sea level instead of the height difference between the two stations.
Topic Mastery Checklist
- Differentiate between weather and climate and list standard meteorological instruments
- Analyze the dual roles of the Southwest Monsoons and Northeast Trades in West Africa
- Explain the seasonal movement of the ITCZ and its impact on rainfall regimes in Ghana
Test Your Knowledge
Ready for the Topic Quiz?
3 WAEC-standard multiple choice questions with instant explanations.
Student Study Notes & Discussion
Share what you understood, ask questions, or drop helpful revision tips on Weather, Climate and Climate Classification.
0 Notes
Loading community notes...