Answer : D
Explanation :
* Statement 1 is correct as The Westerlies are a belt of prevailing winds that blow from the west towards the east. They are located in the mid-latitudes, which are the regions between 30° and 60° latitude north and south of the equator. These winds play a significant role in shaping the climate and weather patterns in the mid-latitudes.
* Statement 2 is correct as The Westerlies are responsible for the movement of weather systems, such as cyclones and anticyclones, across continents like North America and Europe. The Westerlies drive the movement of high and low-pressure systems, including cyclones and anticyclones. These weather systems can bring various weather conditions, such as rain, snow, heatwaves, or cold snaps. The Westerlies' influence on the movement of these systems helps distribute weather patterns across continents.
* Statement 3 is correct as The Westerlies are strongest in the Southern Hemisphere due to the lack of landmasses to disrupt their flow. The Southern Hemisphere has fewer landmasses than the Northern Hemisphere, which allows the Westerlies to flow more freely. As a result, the Westerlies are generally stronger and more consistent in the Southern Hemisphere. This, in turn, affects the climate and weather patterns in regions such as Australia, New Zealand, and southern South America.
Theme : Climatology

Answer : C
Explanation :
* Statement 1 is correct as During El Niño, the trade winds in the Pacific Ocean weaken, which reduces the upwelling of cold, nutrient-rich water off the coast of South America. This disrupts marine ecosystems and affects global weather patterns.
* Statement 2 is incorrect as El Niño typically reduces hurricane activity in the Atlantic Ocean, not increases it. During El Niño, increased wind shear in the Atlantic suppresses the formation and intensification of hurricanes.
* Statement 3 is correct as El Niño causes shifts in atmospheric circulation, leading to drier conditions and droughts in regions like Australia and Southeast Asia.
Theme : Climatology
Level : Moderate
PYQs : UPSC CSE 2011 (El Nino and La nina) + CDS 2022 (El Nino) + CAPF (El Nino and jet stream)

Answer : A
Explanation :
* Statement 1 is correct as The Himalayas and other mountain ranges block moisture-laden air from the Indian Ocean, creating a rain shadow effect that contributes to the arid conditions in the Gobi Desert.
* Statement 2 is correct as The Gobi Desert's location in the continental interior, far from moisture sources like oceans, also contributes to its arid climate.
* Statement 3 is incorrect as The Gobi Desert is not influenced by warm ocean currents, as it is far from any ocean.
Theme : Geomorphology
Level : Moderate
PYQs relevance : CSE 2009 (Formation of desert)

Answer : C
Explanation :
* Statement 1 is correct as The ozone layer (O₃) in the stratosphere absorbs harmful ultraviolet (UV) radiation from the Sun. This absorption converts UV energy into heat, warming the stratosphere. This is the “primary reason” temperatures increase with altitude in this layer.
* Statement 2 is incorrect as The stratosphere’s temperature increase is not due to proximity to the Sun. The entire Earth’s atmosphere is roughly the same distance from the Sun. If this were true, the thermosphere (higher up) would be even hotter, but temperatures there fluctuate widely due to solar activity, not proximity.
* Statement 3 is correct as The stratosphere is stable with minimal vertical air movement (no convection). Heat from ozone absorption accumulates in the stratosphere without being redistributed, leading to a temperature inversion (warmer with altitude).
Theme : Climatology
Level : Moderate
PYQs relevance : UPSC CDS 2016 (Stratosphere and temperature) + CDS (stratosphere and ozone) + UPSC CSE 2011 (Conceptual Question on Stratosphere)

Answer : D
Explanation :
* Statement 1 is correct as Polar regions experience 24 hours of daylight during summer due to the tilt of the Earth's axis. This phenomenon is called the Midnight Sun. The continuous sunlight allows for significant heating of the surface, even though the Sun's angle is low. This results in relatively warmer temperatures during the summer months.
* Statement 2 is correct as Conversely, during the winter months, the polar regions experience almost complete darkness, leading to extreme cooling.
* Statement 3 is correct as The polar regions have very low humidity, which allows for rapid temperature changes. With little to no moisture in the air, the atmosphere can't retain heat well, leading to rapid cooling. Similarly, when the sun shines, the air can heat up quickly due to the lack of moisture.
Theme : Climatology
Level : Easy to moderate