Consider the following statements regarding vertical distribution of temperature in ocean water :
(i) The temperature falls very rapidly up to the depth of 200m and thereafter the rate of decrease of
temperature is slowed down.
(ii) The rate of decrease of temperature with increasing depth is more rapid near the equator than towards the
poles.
Which of the above statements is/are correct?
a)
i only
b)
ii only
c)
i and ii
d)
None
Correct answer is option 'C'. Can you explain this answer?

Question

Consider the following statements regarding vertical distribution of temperature in ocean water :

(i) The temperature falls very rapidly up to the depth of 200m and thereafter the rate of decrease of
temperature is slowed down.
(ii) The rate of decrease of temperature with increasing depth is more rapid near the equator than towards the
poles.

Which of the above statements is/are correct?

a)
i only
b)
ii only
c)
i and ii
d)
None

Correct answer is option 'C'. Can you explain this answer?

Answer

Heat is transmitted to the lower sections of the oceans through the mechanism of conduction from the surface of ocean water. Also, the second statement can be explained by the fact that though the surface temperature of the seas decreases from equator towards the poles, but the temperature at the ocean bottoms is uniform from the equator towards the pole.

Answer

Hey Kunika, glad to answer the question.
The right answer is C and the explanation is as follows :

The maximum temperature of the oceans is always on the surface because it directly receives the insolation (Incoming Solar Radiation aka insolation). The heat is transmitted to the lower sections of the oceans through the mechanism of conduction.

Solar rays very effectively penetrate up to 20m depth and they seldom go beyond 200m depth. Consequently, the temperature decreases from the ocean surface with increasing depth but the rate of decrease of temperature with increasing depth is not uniform everywhere. The temperature falls very rapidly up to the depth of 200m and thereafter the rate of decrease of temperature is slowed down.

Second part includes warm at equator and cold at poles. So here you go :
Average temperature of surface water of the oceans is 26.7°C and the temperature gradually decreases from equator towards the poles. The rate of decrease of temperature with increasing latitudes is generally 0.5°C per latitude. The average temperatures become 22°C at 20° N and S latitudes, 14°C at 40° N and S latitude, and 0°C near the poles.

Hope that you could find some content in knowing the reason now.

Thank You

Answer

The correct answer is option (c) i and ii.

Explanation:
(i) The temperature falls very rapidly up to the depth of 200m and thereafter the rate of decrease of temperature is slowed down.

- The first statement is correct. In the ocean, the temperature decreases rapidly with increasing depth up to a certain point, known as the thermocline. The thermocline is usually located at a depth of around 200 meters. Below this depth, the rate of decrease in temperature slows down significantly.

- The rapid decrease in temperature in the upper 200 meters of the ocean is primarily due to solar radiation. Sunlight penetrates the ocean surface and heats the upper layers, creating a warm surface layer. However, as we go deeper, the sunlight gets absorbed and the heat dissipates, causing a decrease in temperature.

- The rate of decrease in temperature is influenced by various factors such as latitude, season, and ocean currents. However, in general, the temperature gradient is steeper in the upper layers and becomes less steep below the thermocline.

(ii) The rate of decrease of temperature with increasing depth is more rapid near the equator than towards the poles.

- The second statement is also correct. Near the equator, the rate of decrease in temperature with depth is more rapid compared to the polar regions. This is because the equatorial regions receive more direct sunlight, leading to a stronger temperature gradient.

- The equatorial regions receive more solar radiation, resulting in a larger temperature difference between the surface and deeper layers. As a result, the temperature decreases more rapidly with increasing depth near the equator.

- On the other hand, towards the poles, the sunlight is more oblique, and the solar radiation is spread over a larger area. This leads to a smaller temperature difference between the surface and deeper layers, resulting in a slower rate of decrease in temperature with depth.

In conclusion, both statements (i) and (ii) are correct. The temperature falls rapidly up to a depth of 200 meters in the ocean, and the rate of decrease of temperature is more rapid near the equator compared to the poles.

Similar UPSC Doubts

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Regarding ocean temperatures, consider the following statements: 1. Highest temperature is observed in open seas2. The ocean temperature decreases with depth3. The temperature of oceans constantly reduces near the polar regions in every part of the globeWhich of the above is/are incorrect?

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