Chapter 30, Problem 1TE

Earth is closest to the Sun in January, but January is cold in the Northern Hemisphere. Why?

To determine

The reason for colder January in the Northern Hemisphere.

Answer to Problem 1TE

January is cold in the northern region because the Earth is tilted and due to this, the side of the Northern hemisphere is away from the Sun. So it gets less amount of daylight as compared to the Southern hemisphere.

Explanation of Solution

In January, the Earth is closest to the Sun, but January is cold in the northern hemisphere because, at that time, the state of the Earth is in tilted condition. Due to this tilted condition of the Earth, the Earth's northern hemisphere always goes away from the Sun, and the less amount of daylight reaches into the northern hemisphere. So less amount of heat generation takes place, and due to this, the northern hemisphere's temperature decreases.

But at the same time, the southern hemisphere gets a large amount of daylight as compared to the northern hemisphere, so heat generation is massive in the southern hemisphere. Due to this reason, January is cold in the Northern Hemisphere; even the Sun is closest to the Sun in January.

Conclusion:

Therefore, January is cold in the northern region because the Earth is tilted and due to this, the side of the Northern hemisphere is away from the Sun. So it gets less amount of daylight as compared to the Southern hemisphere.