Which of the following is a characteristic of the isotherms in the Southern Hemisphere?

The correct option is They are more gradual and parallel to latitudes..

Explanation

Isotherms are imaginary lines connecting places with equal temperatures. Their horizontal distribution and pattern are significantly influenced by the differential heating and cooling of land and water bodies. The presence of vast oceans versus large landmasses determines whether these lines are regular or irregular.

Analysis of Isotherm Patterns:

• Southern Hemisphere: This hemisphere is dominated by vast oceans, with significantly less landmass compared to the Northern Hemisphere. Water heats and cools more slowly and uniformly than land. Due to the absence of large landmasses to disrupt the temperature gradient, the temperature changes gradually from the equator toward the poles. Consequently, the isotherms are generally regular, straight, and parallel to the latitudes.
• Northern Hemisphere: In contrast, the Northern Hemisphere contains large landmasses. The stark temperature contrast between land and sea (land being hotter in summer and colder in winter than the adjacent ocean) causes isotherms to bend sharply at continental margins. This results in an irregular and discontinuous pattern.

Option Analysis:

• They show sharp bends over continents. is incorrect: Sharp bends over continents are a characteristic of the Northern Hemisphere due to the land-sea contrast.
• They are irregular and discontinuous. is incorrect: Irregularity is a feature of the Northern Hemisphere isotherms.
• They are more gradual and parallel to latitudes. is correct: The dominance of water in the Southern Hemisphere ensures a uniform temperature gradient, making isotherms parallel to latitudes.
• They are concentrated only around the equator. is incorrect: Isotherms are mapped across the entire globe to represent temperature distribution, not just around the equator.

Key Takeaway:

The Southern Hemisphere is often called the "Water Hemisphere." Due to the dominance of oceans and lack of land interference, isotherms there are regular and run parallel to the latitudes, unlike the irregular isotherms of the Northern Hemisphere.