Question

When the sun is overhead on the Tropic of Capricorn (22nd December) the pressure belts shift _____________.

• A. $5^{0}N$
• B. $5^{0}S$
• C. ${15}^{0}N$
• D. ${15}^{0}S$

Answer 1

The correct option is B $5^{0}S$

$5^{0}S$

When the sun is overhead on the Tropic of Cancer (21 June) the pressure belts shift 5° northward and when it shines vertically overhead on Tropic of Capricorn (22 December), they shift 5° southward from their original position.

Because the axis of the Earth is tilted. If the Earth rotated upright the sun will always shine perpendicular to the Equator so the pressure belts would not move. But the Earth’s axis is slightly tilted. So in Summer, the northern hemisphere is pointed to the sun and in Winter southern hemisphere is pointing away from the sun. That is why days are longer in summer than in winter. The pressure belts move with the energy the sun provides. So if it is Summer in the Northern Hemisphere the pressure belts move towards the north. If it is Summer in the Southern Hemisphere, the pressure belts move further south.