UPSC Previous Year Questions (Prelims): Climatology | Geography for UPSC CSE PDF Download

Q.1. Consider the following statements:   (2021)

1. In the tropical zone, the western sections of the oceans are warmer than the eastern sections owing to the influence of trade winds.
2. In the temperate zone, westerlies make the eastern sections of oceans warmer than the western sections.

Which of the statements given above is/are correct?   
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

Correct Answer is Option (c)

• Statement 1 is correct: Warmer water is transported westward in the ocean by the Northeast trade winds in the Northern hemisphere of the tropical zone (as the figure given below shows). So, in tropical zones, the western section of ocean is warmer than eastern sections due to trade winds.  
• Statement 2 is correct: Similarly, the Westerlies play an important role in carrying the warm, equatorial waters and winds to the western coasts of continents (that is eastern section of the Oceans in temperate zone). Thus, in temperate zones, westerlies make the eastern section of the ocean warmer than the western sections.  

Q.2. Consider the following statements:    (2020-I)

1. Jet streams occur in the Northern Hemisphere only.
2. Only some cyclones develop an eye.
3. The temperature inside the eye of a cyclone is nearly 10º C lesser than that of the surroundings.

Which of the statements given above is/are correct:
(a) 1 only
(b) 2 and 3 only
(c) 2 only
(d) 1 and 3 only

Correct Answer is Option (c)

• Jet streams are high altitude westerly wind system blows at a height of 6 to 14 km, with very high speed up to 450 km/hr in the wavy form at both hemispheres.  So #1 is wrong. 
• The Centre of the cyclone is called an Eye. The eye is a Calm region with no rainfall and experiences the highest temperature and lowest pressure within the cyclonic system.  So  #3 is wrong. So, by elimination, the answer is (c).

Q.3. With reference to Ocean Mean Temperature (OMT), which of the following statements is/are correct?   (2020-I) 

1. OMT is measured up to a depth of 26°C isotherm which is 129 meters in the south-western Indian Ocean during January – March. 
2. OMT collected during January March can be used in assessing whether the amount of rainfall in monsoon will be less or more than a certain long-term mean 

Select the correct answer using the code given below 
(a) 1 only 
(b) 2 only 
(c) Both 1 and 2 
(d) Neither 1 nor 2

Correct Answer is Option (b)

• OMT is measured up to a depth of 26 degrees C isotherm. During January–March, the mean 26 degrees C isotherm depth in the Southwestern Indian Ocean is 59 meters. So, #1 is wrong. 
• Sea surface temperature (SST) is routinely used for predicting whether the total amount of rainfall that India receives during the monsoon season will be less or more than the long-term mean. However, ocean means temperature (OMT) has a better ability to predict this, than SST. So, #2 is correct.

Q.4. Which of the following statements are correct about the deposits of methane hydrate? (2019-I) 

1. Global warming might trigger the release of methane gas from these deposits. 
2. Large deposits of 'methane hydrate' are found in Arctic Tundra and under the seafloor. 
3. Methane in the atmosphere oxidizes to carbon dioxide after a decade or two.

Select the correct answer using the code given below:
(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3

Correct Answer is Option (d)
As per the NASA webpage: 

• Large amounts of methane are frozen in Arctic tundra soils and in marine sediments including gas hydrates. As Earth's climate warms, that methane is vulnerable to possible release into the atmosphere, where it can add to global warming. So 1 and 2 are correct. 
• In Methane Cycle, every molecule of methane that goes into the atmosphere remains there for 8 years until it is removed by oxidation into carbon dioxide (CO₂) and water (H₂O). So, 3 is also correct. This, answer (d): All three are correct.

Q.5. On 21st June the sun  (2019-I)
(a) Does not set below the horizon at the Arctic circle
(b) Does not set below the horizon at Antarctic circle
(c) Shines vertically overhead at noon on the Equator
(d) Shines vertically overhead at the tropic of Capricorn

Correct Answer is Option (a)

• On 21st June, the Northern Hemisphere is tilted towards the sun. The rays of the sun fall directly on the Tropic of Cancer. So, (c) and (d) are wrong. 
• Places beyond the Arctic Circle experience continuous daylight for about six months. So (a) is correct.

Q.6. Consider the following statements:   (2018-I) 

1. The Earth's magnetic field has reversed every few hundred thousand years. 
2. When the Earth was created more than 4000 million years ago, there was 54% oxygen and no carbon dioxide. 
3. When living organisms originated, they modified the early atmosphere of the Earth. 

Which of the statements given above is/are correct?
(a) 1 only 
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3

Correct Answer is Option (c)

NCERT Biology Class 12 page 127: “There was no atmosphere on early earth. Water vapor, methane, carbon dioxide, and ammonia released from molten mass covered the surface.” So #2 is wrong, CO₂ was present, we are left with (a) or (c). In both options the first statement is correct but experts were divided over the third statement because the early Early atmosphere of earth had no free oxygen, the (life) forms until then could at best be only “anaerobic”. So those living organisms did not have the capacity to alter the atmosphere, at least not in a significant manner. Accordingly, some ticked  ‘a’ while others ticked ‘c’. UPSC has kept ‘c’ as the official answer.

Q.7. Consider the following statements    (2015 - I) 

1. The winds which blow between 30° N and 60° S latitudes throughout the year are known as westerlies. 
2. The moist air masses that cause winter rains in the NorthWestern region of India are part of westerlies. 

Which of the statements given above is/are correct?
(a) 1 only
(b) 2 only 
(c) Both 1 and 2
(d) Neither 1 nor 2

Correct Answer is Option (b)
The Westerlies are prevailing winds from the west toward the east in the middle latitudes between 30 and 60 degrees latitude. They originate from the high-pressure areas in the horse latitudes and tend towards the poles and steer extratropical cyclones in this general manner. The moist air masses that cause winter rains in the North-Western region of India are part of westerlies.

Q.8. The annual range of temperature in the interior of the continents is high as compared to coastal areas. What is/are the reason/reasons?       (2013 - I) 

1. Thermal difference between land and water 
2. Variation in altitude between continents and oceans 
3. Presence of strong winds in the interior 
4. Heavy rains in the interior as compared to coasts 

Select the correct answer using the codes given below.
(a) 1 only
(b) 1 and 2 only 
(c) 2 and 3 only
(d) 1, 2, 3 and 4

Correct Answer is Option (a)
The first statement is correct. One major factor affecting the distribution of the temperature of Earth is the distribution of Land and Oceans. Since there is more land in Northern Hemisphere and more waters in the Southern hemisphere and there is a big difference between the specific heat of land and water; the loss of heat from the continents is bigger than the oceans. The continents get heated faster and get cooled faster in comparison to the Oceans. This is the reason that the temperatures of the Oceans are moderate while that of continents is extreme. The moderating effect on the temperature of the land due to the proximity of the seas is called Maritime influence. The increasing effect on the temperature of the land in the interior of the continents is called Continental Influence.

Q.9. Consider the following factors:    (2012 - I) 

1. Rotation of the Earth 
2. Air pressure and wind 
3. Density of ocean water 
4. Revolution of the Earth 

Which of the above factors influence the ocean currents?
(a) 1 and 2 only
(b) 1, 2 and 3
(c) 1 and 4
(d) 2, 3 and 4

Correct Answer is Option (b)

1. Rotation of the Earth
2. Air pressure and wind
3. Density of ocean water. 

Revolution has no impact on ocean currents.

Q.10. The jet aircraft fly very easily and smoothly in the lower stratosphere. What could be the appropriate explanation?      (2011 - I)

1. There are no clouds or water vapor in the lower stratosphere. 
2. There are no vertical winds in the lower stratosphere. 

Which of the statements given above is/are correct in this context?  
(a) 1 only
(b) 2 only 
(c) Both 1 and 2
(d) Neither 1 nor 2

Correct Answer is Option (c)
Jet flies in the lower stratosphere to avoid turbulence. There are no clouds and the air is dry with little water vapor. There are no vertical winds in the lower stratosphere.

Q.11. What could be the main reason/reasons for the formation of the African and Eurasian desert belt?      (2011 - I) 

1. It is located in the subtropical high-pressure cells. 
2. It is under the influence of warm ocean currents. 

Which of the statements given above is/are correct in this context?
(a) 1 only
(b) 2 only 
(c) Both 1 and 2
(d) Neither 1 nor 2

Correct Answer is Option (a)
It is under the influence of cold ocean currents. So given the second statement is wrong.

Q.12. Westerlies in the southern hemisphere are stronger and persistent than in the northern hemisphere. Why?     (2011 - I) 

1. The southern hemisphere has less landmass as compared to the northern hemisphere. 
2. Coriolis force is higher in the southern hemisphere as compared to the northern hemisphere. 

Which of the statements given above is/are correct?
(a) 1 only 
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

Correct Answer is Option (a)
The speed of these winds is higher and more persistent in the southern hemisphere. The land mass in the southern hemisphere is lesser in comparison to the northern hemisphere. As these winds cross the landmass its velocity decreases. Thus the effect of westerlies is less over the northern hemisphere than in the southern hemisphere.

Q.13. A layer in the Earth’s atmosphere called the ionosphere facilities radio communication. Why?      (2011 - I)

1. The presence of ozone causes the reflection of radio waves to the earth. 
2. Radio waves have a very long wavelength.

Which of the statements given above is/are correct?
(a) 1 only
(b) 2 only  
(c) Both 1 and 2 
(d) Neither 1 nor 2

Correct Answer is Option (b)
Statement 1 is wrong, ionosphere contains charged particles due to which electromagnetic radio waves get reflected and communication becomes possible. Ozone is found mainly in the stratosphere and in traces in the troposphere. Its main function is the absorption of UV rays. While the ions give the ionosphere its name, it is the free electrons that affect the radio waves and radio communications. Also, Radio waves have the longest wave length in the EM spectrum.

Q.14. What causes the wind to deflect toward the left in the Southern Hemisphere?      (2010)
(a) Temperature
(b) Magnetic field 
(c) Rotation of the earth 
(d) Pressure

Correct Answer is Option (c)
Rotation of the earth causes the wind to deflect towards the left in the Southern Hemisphere.

Q.15. A geographic region has the following distinct characteristics:    (2010) 

1. Warm and dry climate 
2. Mild and wet winter 
3. Evergreen Oak trees 

The above features are distinct characteristics of which one of the following regions?
(a) Mediterranean
(b) Eastern China
(c) Central Asia 
(d) Atlantic coast of North America

Correct Answer is Option (a)
Mediterranean climate has mild, rainy winter and hot, dry summers and Evergreen, Oak trees

Q.16. Consider the following statements:     (2008) 

1. Albedo of an object determines its visual brightness when viewed with reflected light. 
2. Albedo of Mercury is much greater than the albedo of the Earth. 

Which of the statements given above is/are correct?
(a) 1 only 
(b) 2 only
(c) Both 1 and 2 
(d) Neither 1 nor 2

Correct Answer is Option (a)
Albedo is the fraction of the incident sunlight that is reflected. When an object reflects most of the light that hits it and looks bright then it has a high albedo. The albedo of mercury is 0.1 and that of the earth is 0.30.

Q.17. Assertion (A): Wind patterns are clockwise in the Northern Hemisphere and anti-clockwise in the Southern Hemisphere. 
Reason (R): The directions of wind patterns in the Northern and the Southern Hemisphere are governed by the Coriolis effect.   (2005) 
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is NOT a correct explanation of A 
(c) A is true but R is false
(d) A is false but R is true

Correct Answer is Option (a)
A is true as the direction of the wind in the north ern hemisphere is clock wise and in the southern hemisphere, it is anti clock wise. The explanation is correct as this is mainly due to the Coriolis effect.

Q.18. Assertion (A): Existence of human life on Venus is highly improbable.
Reason (R): Venus has extremely high level of carbon dioxide in its atmosphere.     (2005)
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is NOT a correct explanation of A 
(c) A is true but R is false
(d) A is false but R is true

Correct Answer is Option (a)
The atmosphere of Venus is composed primarily of carbon dioxide and much denser and hotter than that of Earth. The atmosphere of Venus supports opaque clouds made of sulfuric  acid, making optical Earth-based and orbital observation of the surface impossible.

Q.19. Assertion (A): Thickness of the atmosphere is maximum over the Equator.
Reason (R): High insolation and strong convection currents occur over the Equator.     (2004) 
(a) Both A and R are individually true and R is the correct explanation of A 
(b) Both A and R are individually true but R is not the correct explanation of A 
(c) A is true but R is false 
(d) A is false but R is true

Correct Answer is Option (d)
The circulation of atmosphere and oceans is fundamentally caused by the fact that the amount of incoming solar radiation varies from a maximum at the equator to a minimum at the poles. More reflection and absorption of incoming radiation takes place in high latitude because of the greater thickness of atmosphere that must be penetrated. Thickness of the earth is maximum over the pole.

Q.20. Assertion (A): 60° - 65º latitudes in both the hemispheres have a low pressure belt instead of high pressure.
Reason (R): The low pressure areas are permanent over oceans rather than on land.     (2002) 
(a) Both A and R are true and R is the correct explanation of A
(b) Bot h A and R a re tr ue but R is NOT a corr ect explanation of A 
(c) A is true but R is false
(d) A is false but R is true

Correct Answer is Option (c)
A is true but R is false. Sub-polar low pressure is located between 60–65º latitude in both hemisphere. Low pressure is produced in this area, because the surface air spreads outward from this zone due to rotation of earth.

Q.21. Consider the following statements: (2002) 

1. Ocean currents are slow-surface movement of water in the ocean. 
2. Ocean currents assist in maintaining the Earth's heat balance 
3. Ocean currents are set in motion primarily by prevailing winds 
4. Ocean currents are affected by the configuration of the ocean 

Which of these statements are correct?
(a) 1 and 2
(b) 2, 3 and 4
(c) 1, 3 and 4 
(d) 1, 2, 3 and 4

Correct Answer is Option (b)
Ocean currents are not slow most of the time and can be subsurface current also. So, statement '1' is wrong. But '2', '3' and '4' statements are correct.

Q.22. In the given map, which one of the following pairs of ocean currents are shown?   (1999)
(a) Benguela and Falkland 
(b) Canary and Humboldt
(c) Agulhas and Guinea
(d) Benguela and Guinea

Correct Answer is Option (d)
Benguela is a cold current flows from south to north along the west coast of Africa. Guinea current is a warm current flowing east of Guinea along the west coast of Africa.

Q.23. The correct sequence of different layers of the atmosphere from the surface of the Earth upwards is:   (1998) 
(a) Troposphere, Stratosphere, Ionosphere, Mesosphere 
(b) Stratosphere, Troposphere, Ionosphere, Mesosphere 
(c) Troposphere, Stratosphere, Mesosphere, Ionosphere 
(d) Stratosphere, Troposphere, Mesosphere, Ionosphere

Correct Answer is Option (c)
The correct sequence of different layers of atmosphere from the surface of earth is Troposphere, Stratosphere, Mesosphere and Ionosphere. Troposphere extends upto 8 km from earth surface, but at equator it is 16–18 km. Stratosphere extends above Troposphere 18–50 km. Mesosphere extends up to 80 km and above Mesosphere Ionosphere is present, which extends up to 400 km.