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Whenever a tropical cyclone moves to land, much of its severity is reduced. This is because 1. its source of moisture is cut off 2. the friction over land kills tropical cyclones Select the correct answer using the code given below.
Explanation
Tropical cyclones are essentially heat engines powered by the release of latent heat of condensation [2]. This energy is derived from the continuous supply of moisture gathered as winds move over warm ocean surfaces [2]. Upon making landfall, the storm is physically cut off from this primary moisture source, depriving it of the latent heat necessary to sustain its intensity, which leads to rapid dissipation [3]. While land surfaces do have higher roughness (friction) compared to the ocean, which can reduce sustained wind speeds and increase turbulence, friction is not the primary cause of the cyclone's death. In fact, increased surface roughness can sometimes momentarily enhance the overturning circulation or gusts, but the lack of thermodynamic fuel (moisture) is the definitive reason for the rapid weakening and eventual decay of the system.
Sources
- [2] INDIA PHYSICAL ENVIRONMENT, Geography Class XI (NCERT 2025 ed.) > Chapter 6: Natural Hazards and Disasters > Tropical Cyclone > p. 59
- [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 26: Tropical Cyclones > Why Do Tropical Cyclones Weaken On Landfall? > p. 355
- [3] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 9: Atmospheric Circulation and Weather Systems > Tropical Cyclones > p. 83