Question 1: What is the 'Hadley Cell' in atmospheric circulation?

Answer: A large-scale atmospheric convection cell in tropical regions that circulates air between the equator and subtropics, influencing climate patterns.

Question 2: Define 'monsoon' and give an example of a monsoon system.

Answer: A seasonal wind pattern causing wet and dry periods; for example, the Indian Monsoon.

Question 3: Explain 'climate variability' with an example.

Answer: Variations in climate over time due to natural or anthropogenic factors, such as the El Niño-Southern Oscillation causing fluctuations in rainfall and temperature.

Question 4: What is meant by 'atmospheric pressure' and how does it influence weather patterns?

Answer: The force exerted by atmospheric gases; variations in pressure drive wind and influence weather systems.

Question 5: Name the main greenhouse gases involved in climate regulation.

Answer: Carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), and water vapor.

Question 1: Which atmospheric circulation pattern is primarily responsible for the formation of deserts such as the Sahara?

Answer: The Subtropical High Pressure Belt (Horse Latitudes)

Question 2: Name the key processes involved in the development of a tropical cyclone.

Answer: Warm ocean water evaporation, low atmospheric pressure, Coriolis effect, and the release of latent heat driving cyclonic convection.

Question 3: Identify the typical climatic characteristics of the Amazon rainforest.

Answer: High rainfall, high temperatures year-round, humidity, and dense vegetation.

Question 4: What is the primary cause of the monsoon winds in South Asia?

Answer: The differential heating of land and sea between the Indian Ocean and the Asian landmass.

Question 1: The El Niño phenomenon causes significant alterations in weather patterns across the Pacific region and beyond. Based on the case study, identify two impacts of El Niño on global weather and discuss their effects on at least two different regions.

Answer: El Niño leads to increased rainfall and flooding in South America, notably in Ecuador and Peru, causing damage to agriculture and infrastructure. Conversely, it causes drought and heatwaves in Australia and Indonesia, impacting water resources and agriculture productivity.

Question 2: Explain how the variations in sea surface temperatures during El Niño influence atmospheric circulation and weather patterns worldwide.

Answer: Warmer sea surface temperatures in the central and eastern Pacific disrupt normal atmospheric circulation, weakening trade winds, shifting jet streams, and leading to altered rainfall and temperature patterns globally, including droughts in Southeast Asia and heavy rainfall in the Americas.

Question 1: Analyse the causes of the Sahara Desert's expansion over recent decades.

Answer: The expansion is primarily driven by prolonged droughts, desertification due to overgrazing and deforestation, climate change leading to altered rainfall patterns, and natural variability in climate systems. Human activities exacerbate these processes, reducing vegetation cover and increasing aridity.

Question 2: Explain why the Amazon rainforest is vulnerable to climate variability and deforestation.

Answer: The Amazon's climate depends on high rainfall and stable temperatures. Climate variability can cause droughts that stress ecosystems, while deforestation reduces humidity and disrupts rainfall cycles, leading to further droughts and loss of biodiversity.

Question 3: Analyse the role of the Intertropical Convergence Zone in tropical rainfall distribution.

Answer: The ITCZ is a belt of low pressure around the equator where trade winds from both hemispheres converge, causing intense convection and rainfall. Its migration influences seasonal rainfall patterns in tropics like West Africa and Central America, with peak rainfall during its position over land.

Question 1: To what extent are current strategies effective in managing the impacts of climate variability and change in regions such as the Sahel and Amazon?

Answer: Strategies such as reforestation, sustainable land management, and climate adaptation programs have had mixed success. In the Sahel, efforts like agroforestry and water conservation have improved resilience, but challenges remain due to ongoing desertification and political instability. In the Amazon, policies to curb deforestation are crucial but often compromised by economic pressures. A comprehensive approach combining policy, community engagement, and international cooperation is necessary for effective management.