CBSE Class 9 Geography Chapter 4 - Climate PDF

Important Questions for Class 9 Social Science Geography Chapter 4 - Climate 1. Describe what is meant by "weather" and "climate." Talk about the variations. Ans: Weather and climate are terms often used interchangeably but represent different concept...

Important Questions for Class 9 Social Science Geography Chapter 4 - Climate 1. Describe what is meant by "weather" and "climate." Talk about the variations. Ans: Weather and climate are terms often used interchangeably but represent different concepts related to atmospheric conditions. Weather refers to the short-term atmospheric conditions in a specific place at a particular time. It includes daily variations in temperature, humidity, precipitation, wind speed, and visibility. For example, weather can describe whether it’s sunny, rainy, or windy on a given day. Climate, on the other hand, refers to the long-term average of weather conditions over a significant period, typically 30 years, in a particular region. It encompasses the patterns and variations in temperature, precipitation, and other atmospheric conditions that define the overall character of a place's weather over time. Differences Between Weather and Climate: Duration: Weather describes short-term atmospheric conditions, usually over hours or days, while climate is the average of weather patterns over a long period, such as 30 years. Scope: Weather focuses on immediate conditions, like a rainy day or a sunny afternoon, whereas climate provides a broader view of typical weather patterns, such as the overall warmth or coldness of a region. Predictability: Weather forecasts can predict conditions for the near future, such as the next few days, but climate describes the expected conditions over many years, helping to identify long-term trends and patterns. Class IX Social Science www.vedantu.com 1  Impact: Weather affects daily activities and immediate decisions, like what to wear or whether to carry an umbrella. Climate influences broader aspects of life, including agriculture, construction, and long-term planning. 2. Why do Rajasthani homes have flat roofs and strong walls? Ans: In Rajasthan, houses are constructed with thick walls and flat roofs to address the extreme climatic conditions of the region. The thick walls provide excellent heat insulation, keeping indoor spaces cooler by absorbing and slowly releasing heat throughout the day. This design also offers protection against sandstorms and dust. Flat roofs are practical in arid environments as they facilitate rainwater harvesting during rare rainfall events, which is crucial for drinking and irrigation. Flat roofs serve as extra living space, allowing for activities like sleeping under the stars, drying clothes, or storing goods. This architectural approach effectively manages the severe temperatures and water scarcity typical of Rajasthan. 3. Why are homes in Assam constructed on stilts, whereas homes in the Tarai area, Goa, and Mangalore have sloping roofs? Describe. Ans: Houses in the Tarai region, Goa, and Mangalore have sloping roofs primarily due to the heavy rainfall experienced in these areas. Sloping roofs allow rainwater to easily slide off, preventing water accumulation that could lead to leaks or structural damage. This design is particularly effective in handling the intense monsoon rains common in these regions. Class IX Social Science www.vedantu.com 2  In contrast, houses in Assam are built on stilts to address the challenges posed by frequent flooding and heavy rains. Elevated on stilts, these houses are protected from water damage and remain habitable even during flood conditions. This construction technique also helps to avoid dampness and keeps the living areas cooler by allowing air circulation underneath the house. Both architectural styles are well-suited to the specific climatic and environmental conditions of their respective regions. 4. Why are the majority of the world's deserts found near the subtropical western edges of continents? Ans: Most of the world's deserts are located in the western margins of continents in the subtropics due to a combination of climatic and atmospheric factors. This pattern is largely influenced by the global circulation of winds and ocean currents. In the subtropical regions, the dominant winds are the trade winds, which blow from east to west. When these winds reach the western margins of continents, they encounter cooler ocean currents and high-pressure systems. This combination leads to the formation of dry, descending air, which inhibits cloud formation and precipitation. As a result, these areas experience arid conditions and are prone to desertification. The presence of cold ocean currents along these western margins further contributes to the aridity by cooling the air and reducing its moisture-carrying capacity. This creates a climatic zone where deserts are more likely to develop, as seen in regions like the Atacama Desert in Chile and the Namib Desert in Namibia. 5. Almost all of India receives very little rain during the northeast monsoon. The mango showers are favourable to local winds. Explain and list the reasons. Ans: The northeast monsoons, which occur from October to December, generally bring limited rainfall to most parts of India due to the high-pressure system over the Indian Class IX Social Science www.vedantu.com 3 subcontinent. This system results in dry conditions for the majority of the country, except for a few regions. However, the term "mango showers" refers to the pre-monsoon showers that occur in the southwestern part of India, particularly in Kerala and coastal Karnataka. These showers are beneficial for several reasons: 1. Agricultural Impact: Mango showers are crucial for the early onset of the monsoon. They provide much-needed moisture to the soil, helping to prepare it for the main monsoon rains. This early rain is particularly beneficial for crops like mangoes, which rely on these showers to start their growth cycle. 2. Crop Preparation: The showers help in the germination of seeds and improve the soil’s fertility, leading to better crop yields. This is especially important in regions dependent on agriculture for their livelihood. 3. Climate Regulation: Mango showers also contribute to the stabilisation of local climate conditions. They help moderate temperatures and contribute to the overall water balance in the region. 6. Six main factors affect a location's climate. Give them names. Ans: Latitude: Determines the angle and duration of sunlight received at a location, affecting temperature and seasonal variations. Altitude (Elevation): Higher altitudes generally experience cooler temperatures compared to lower altitudes at the same latitude. Pressure and Wind Systems: The distribution of high and low-pressure systems affects wind patterns and, consequently, precipitation and temperature. Class IX Social Science www.vedantu.com 4  Distance from the Sea (Continentality): Areas closer to the sea have moderate temperatures and higher humidity, while inland areas experience more extreme temperature variations. Ocean Currents: Warm and cold ocean currents influence coastal temperatures and precipitation patterns. Topography: The physical features of the land, such as mountains and valleys, can affect local climate by influencing wind patterns and precipitation distribution. 7. Why are the showers that precede the monsoon in Kerala and Karnataka referred to as "mango showers"? Ans: The pre-monsoon showers in Kerala and Karnataka are known as 'mango showers' because they occur when mangoes are in season. These showers, which typically happen between April and May, provide crucial moisture to the soil, aiding in the development and ripening of mangoes. The timing of these showers is closely associated with the mango harvest, which is why they are popularly referred to as 'mango showers'. 8. What variables affect the climate in India? Ans: Latitude: The country’s position between the Tropic of Cancer and the Equator affects its temperature and seasonal variations. Altitude: Elevation impacts temperature and precipitation patterns, with higher altitudes experiencing cooler temperatures. Distance from the Sea: Proximity to the sea moderates temperatures, resulting in milder winters and cooler summers along the coast. Monsoon Winds: The Indian Monsoon winds, influenced by seasonal changes in pressure, bring heavy rainfall during the monsoon season. Class IX Social Science www.vedantu.com 5  Western Disturbances: These are low-pressure systems originating in the Mediterranean that affect northern India, bringing winter rains and influencing winter temperatures. Topography: Mountain ranges like the Himalayas block cold winds from the north and influence rainfall distribution by affecting moisture-laden winds. 9. Compose a succinct note about the Coriolis force. Ans: The Coriolis force is an apparent force caused by the Earth's rotation that influences the direction of moving objects, such as winds and ocean currents. As the Earth spins on its axis from west to east, moving objects are deflected to the right in the Northern Hemisphere and the left in the Southern Hemisphere. This deflection alters wind patterns and ocean currents, impacting weather systems and climate. For instance, the Coriolis force contributes to the formation of trade winds and the rotation of cyclones and anticyclones, making it a crucial factor in understanding atmospheric and oceanic dynamics. 10. Write a paper on cyclonic disturbances in the West. Ans: Western Cyclonic Disturbances (WCDs) are weather systems that originate in the Mediterranean region and move eastwards towards the Indian subcontinent, impacting northwestern India, including states like Punjab, Haryana, and Rajasthan. Occurring mainly between October and March, these disturbances bring significant weather changes, including rainfall and thunderstorms. They are crucial for agriculture in northern India, as they provide essential moisture for winter crops like wheat and barley. Class IX Social Science www.vedantu.com 6  The cyclonic circulation of WCDs also leads to cooler temperatures in the region. Understanding WCDs is vital for weather prediction and agricultural planning. 11. What factors are influencing India's climate? Ans: Latitude: India's vast north-south extent results in a diverse climate, with the northern regions experiencing temperate conditions and the southern parts having a tropical climate. Altitude: Higher altitudes, like those in the Himalayas, experience cooler temperatures compared to the plains and coastal regions. The Himalayas also impact monsoon patterns and regional weather. Pressure and Wind Systems: The seasonal pressure belts and wind patterns, including the southwest and northeast monsoons, significantly influence India's climate. The shifting of these belts affects the distribution of rainfall and temperature. Distance from the Sea: Coastal areas, influenced by the sea, have moderate temperatures with less seasonal variation, while inland areas experience more extreme temperature variations. Ocean Currents: The presence of warm and cold ocean currents around India affects the regional climate. For example, the warm currents in the Indian Ocean influence the monsoon patterns. Topography: The varied landscape, including mountains, plains, and plateaus, affects local weather conditions and precipitation patterns. For instance, the Western Ghats block the monsoon winds, causing heavy rainfall on the windward side and arid conditions on the leeward side. 12. What causes the monsoon-like climate in India? Ans: Class IX Social Science www.vedantu.com 7  Seasonal Wind Patterns: The primary reason is the seasonal reversal of winds. During summer, the Indian subcontinent heats up significantly, creating a low- pressure area that attracts moisture-laden winds from the Indian Ocean. These winds bring heavy rains, particularly during the southwest monsoon season from June to September. Conversely, during winter, the land cools down, leading to high-pressure conditions and dry winds blowing from the land to the sea, known as the northeast monsoon. Geographical Location: India's location between the Tropic of Cancer and the Equator places it in the path of the trade winds and monsoon winds, which are crucial for the monsoon climate. The presence of the Himalayas to the north also plays a significant role by blocking cold winds from Central Asia and causing the moist air from the Indian Ocean to rise and cool, leading to precipitation. Pressure Systems: The differential heating of the land and the ocean creates varying pressure systems. The low pressure over the Indian landmass during summer draws in moist air from the surrounding oceans, while the high pressure over the land in winter results in dry conditions. Orographic Effects: The Western Ghats and the Himalayas further influence the monsoon by causing orographic rainfall. Moist air from the ocean is forced to rise over these mountains, leading to heavy rainfall on the windward side and creating rain shadows on the leeward side. 13. What are the retreating monsoon's four primary traits? Ans: Class IX Social Science www.vedantu.com 8  Gradual Reduction in Rainfall: As the monsoon withdraws, there is a noticeable decrease in rainfall. The intensity and frequency of rain gradually diminish, leading to drier conditions compared to the peak monsoon months. Unpredictable Weather Patterns: The retreating monsoon is often marked by erratic weather patterns. The weather can be unstable, with intermittent rain showers, dry spells, and temperature fluctuations. Temperature Increase: During the retreating phase, temperatures typically rise. The cooling effect of the monsoon winds diminishes, leading to warmer temperatures and higher humidity levels in many parts of the country. Formation of Cyclones: The retreating monsoon period is conducive to the formation of tropical cyclones in the Bay of Bengal and the Arabian Sea. These cyclones can bring heavy rains and strong winds to coastal regions, influencing the weather patterns during this phase. 14. Along the Malabar Coast, which winds are responsible for rainfall? Ans: The winds responsible for rainfall along the Malabar Coast are the South-West Monsoon Winds. These winds blow from the southwest to the northeast during the monsoon season and are driven by the differential heating between the Indian subcontinent and the surrounding oceans. As these winds encounter the Western Ghats, they are forced to rise, cool, and condense, leading to heavy orographic rainfall along the Malabar Coast, which is the southwestern coast of India. 15. Describe jet streams and their impact on India's climate. Ans: 1. Monsoon Onset and Withdrawal: The position and strength of the jet streams affect the timing and intensity of the monsoon winds. For instance, the arrival of the Class IX Social Science www.vedantu.com 9  southwest monsoon is influenced by the shift of the subtropical jet stream. Similarly, the retreat of the monsoon is also affected by the jet streams' movement. 2. Western Disturbances: Jet streams contribute to the formation of Western Disturbances, which are low-pressure systems originating in the Mediterranean region and affecting northern India. These disturbances bring winter rainfall to the northwestern parts of India, including the Punjab and Haryana regions. 3. Temperature Variations: The jet streams' position can influence temperature patterns across India. During certain periods, jet streams can bring cooler air from the north, impacting temperatures and weather conditions in different parts of the country. 16. What makes the monsoon a unifying force? Ans: Uniform Seasonal Impact: The monsoon affects almost the entire country, bringing rainfall that is crucial for agriculture, water supply, and overall ecological balance. This widespread impact means that people across different regions experience the same seasonal changes, fostering a sense of national unity. Agricultural Reliance: India’s agriculture heavily depends on the monsoon rains. The timing and quantity of monsoon rainfall directly influence crop yields and the livelihoods of millions of farmers across various states. This shared dependence on the monsoon creates a common concern and collective experience among people from different regions. Cultural Significance: The arrival of the monsoon is celebrated with numerous festivals and traditions throughout the country. These cultural practices, such as festivals and rituals related to the monsoon, help strengthen the cultural bonds between people from diverse backgrounds. Economic Impact: The monsoon affects various sectors, including agriculture, water resources, and energy production. The economic activities and challenges brought by Class IX Social Science www.vedantu.com 10  the monsoon are experienced nationwide, contributing to a shared economic experience among citizens. Environmental Unity: The monsoon shapes the country's environmental conditions, influencing river flows, soil fertility, and overall ecosystem health. This shared environmental impact creates a sense of unity in addressing ecological and environmental challenges. 17. Over the Indian subcontinent, there is a seasonal reversal in wind direction. Why? Explain. Ans: The seasonal reversal of wind direction over the Indian subcontinent occurs due to the differential heating of land and sea. During summer, the Indian landmass heats up more quickly than the surrounding oceans, creating a low-pressure area over the northern plains and drawing in moist air from the Indian Ocean. This results in the southwest monsoon winds bringing heavy rainfall to the region. Conversely, in winter, the land cools rapidly, creating a high-pressure area, while the surrounding oceans remain relatively warmer. This temperature difference reverses the wind direction, causing dry, cold winds to blow from the land to the sea, which results in the northeast monsoon. This seasonal shift is driven by the varying temperatures and pressures across the land and ocean, influencing the wind patterns throughout the year. Class IX Social Science www.vedantu.com 11 18. Winter rains occur along the Tamil Nadu coast. Why? Provide Justifications. Ans: The Tamil Nadu coast receives winter rainfall primarily due to the northeast monsoon winds. During the winter months, the Indian subcontinent experiences a high-pressure system over northern India as the land cools rapidly. This creates a pressure gradient that drives the northeast monsoon winds from the land towards the sea. As these winds pass over the relatively warmer waters of the Bay of Bengal, they pick up moisture and bring it to the eastern coast of India, including Tamil Nadu. This phenomenon is known as the northeast monsoon or the retreating monsoon. The coastal areas of Tamil Nadu are influenced by weather systems such as tropical cyclones, which can also contribute to winter rainfall in the region. 19. Give an appropriate example to illustrate the differences in India's climate between its regions. Ans: Northern India (Himalayan Region): Climate: The climate varies from alpine in the higher elevations to subtropical in the lower areas. Example: In regions like Shimla and Manali, winters are cold with heavy snowfall, while summers are mild. The higher altitudes experience extreme cold, while the lower foothills have a more temperate climate. Western India (Desert Region): Climate: The Thar Desert exhibits an arid climate with extreme temperature variations between day and night. Class IX Social Science www.vedantu.com 12  Example: In places like Jaisalmer, temperatures can soar above 45°C in summer and drop significantly in winter. Rainfall is scant, contributing to the arid conditions. Southern India (Western Ghats and Coastal Areas): Climate: This region experiences a tropical climate with high humidity and significant rainfall, especially in the coastal areas. Example: The Malabar Coast in Kerala receives heavy rainfall from the southwest monsoon, while the Western Ghats receive orographic rainfall, leading to lush forests and high humidity. Eastern India (Ganges Plain): Climate: The region experiences a humid subtropical climate with heavy monsoon rains. Example: Kolkata experiences hot and humid conditions with heavy rainfall during the monsoon season. The Ganges Plain is characterised by high summer temperatures and abundant rainfall during the monsoon. Central India (Plateau Region): Climate: This region has a varied climate with hot summers and moderate rainfall. Example: In places like Nagpur, summer temperatures can be extremely high, while the monsoon brings moderate rainfall. The climate is influenced by the surrounding plateaus and ranges. 20. Drought is a problem in several areas of Rajasthan, Gujarat, and the leeward side of the Western Ghats. Provide Justifications. Ans: Parts of Rajasthan, Gujarat, and the leeward side of the Western Ghats are prone to drought primarily due to the rain shadow effect and geographical positioning. Class IX Social Science www.vedantu.com 13  The Western Ghats capture moisture-laden winds, causing heavy rainfall on their windward side, while the leeward side, including parts of Karnataka and Maharashtra, remains dry. Rajasthan and Gujarat, located in the northwestern part of India, are far from the moisture sources of the Arabian Sea and the Bay of Bengal, resulting in limited rainfall. High temperatures in these regions lead to increased evaporation, compounding the effects of insufficient and irregular rainfall. The scarcity of water resources and the irregularity of monsoon patterns further exacerbate the drought conditions, impacting agriculture and water availability 21. What is the name of the summertime breeze that blows across the northern plains? (a) Kaal Baisakhi (b) Loo (c) Trade wind (d) None of the above Ans: (b) Loo 22. In _____ in India, the houses are built on stilts. (a) Bihar (b) Assam (c) Goa Class IX Social Science www.vedantu.com 14 (d) None of these Ans: (b) Assam Class IX Social Science www.vedantu.com 15