Which of the following is/are correct inference/inferences from isothermal maps in the month of January?

1. The isotherms deviate to the north over the ocean and to the south over the continent.
2. The presence of cold ocean currents, Gulf Stream and North Atlantic Drift make the North Atlantic Ocean colder and the isotherms bend towards the north.

Select the answer using the code given below:

(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

Explanation

The correct answer is (a) 1 only.

Statement 1: The isotherms deviate to the north over the ocean and to the south over the continent. This is correct. In January, the isotherms bend northward over the oceans due to the warming effect of warm ocean currents like the Gulf Stream and North Atlantic Drift, and they bend southward over the continents due to the cooling effect of the landmasses .
Statement 2: The presence of cold ocean currents, Gulf Stream, and North Atlantic Drift make the North Atlantic Ocean colder and the isotherms bend towards the north. This is incorrect. The Gulf Stream and North Atlantic Drift are warm ocean currents, not cold. They warm the Northern Atlantic Ocean, causing the isotherms to bend northward, indicating warmer temperatures .

Learn more

Isotherms: Lines on a map connecting points with the same temperature at a given time or over a specified period. They are used in meteorology to depict temperature distribution.
January Temperature Distribution:
- Northern Hemisphere: Isotherms deviate north over the ocean due to warm currents like the Gulf Stream and North Atlantic Drift, and south over the continents due to the cooling effect of landmasses.
- Southern Hemisphere: Isotherms are more parallel to latitudes due to the ocean’s moderating effect, leading to more gradual temperature variations.
Factors Influencing Isotherms:
- Latitude: Temperature generally decreases from the equator to the poles.
- Land and Water: Land heats and cools more rapidly than water, causing deviations in isotherms.
- Ocean Currents: Warm currents (e.g., Gulf Stream) cause northward bends, while cold currents cause southward bends.
- Topography: Mountains and valleys can affect local temperature distributions, causing deviations in isotherms.
Seasonal Variations:
- January: More pronounced deviations in the northern hemisphere due to larger landmasses and significant temperature differences between land and sea.
- July: Isotherms generally follow latitudes more closely, with less pronounced deviations compared to January.