Examkin

Question

Difficulty: MediumThe Earth as a Planet and Earth Movements

Earth's revolution around the Sun and its inclined axis cause the apparent movement of the subsolar point throughout the year. Arrange the following seasonal positions of the subsolar point (where the Sun is directly overhead at solar noon) in chronological sequence over a solar year, starting with the March Equinox.

  1. 1The Sun is positioned directly overhead at the Equator (0∘0^\circ) while migrating northward.
  2. 2The Sun reaches its maximum northern declination directly overhead at the Tropic of Cancer (23.5∘N23.5^\circ\text{N}).
  3. 3The Sun crosses the Equator (0∘0^\circ) again while migrating southward.
  4. 4The Sun reaches its maximum southern declination directly overhead at the Tropic of Capricorn (23.5∘S23.5^\circ\text{S}).

Answer

The correct chronological sequence starting from the March Equinox is: (1) Sun overhead at the Equator moving north, (2) Sun overhead at the Tropic of Cancer, (3) Sun overhead at the Equator moving south, and (4) Sun overhead at the Tropic of Capricorn.
The sequence follows the natural annual progression of the overhead Sun (subsolar point). Starting at the March equinox (0∘0^\circ heading north), Earth's revolution brings the Sun overhead at the Tropic of Cancer (23.5∘N23.5^\circ\text{N}) in June, back over the Equator (0∘0^\circ heading south) in September, and finally overhead at the Tropic of Capricorn (23.5∘S23.5^\circ\text{S}) in December.

Step-by-Step Solution

1
Identify the initial benchmark event.
Around March 21 (Vernal Equinox), the Earth's axial tilt places the subsolar point directly over the Equator (0∘0^\circ) as it migrates northward.
This is specified as the starting point for the annual cycle sequence.
2
Determine the next solstice event following three months of revolution.
Around June 21 (June Solstice), the subsolar point reaches its northernmost limit at the Tropic of Cancer (23.5∘N23.5^\circ\text{N}).
Earth's orbit advances 90 degrees, maximizing Northern Hemisphere solar inclination.
3
Trace the subsolar point as Earth continues its revolution toward the next equinox.
Around September 23 (Autumnal Equinox), the subsolar point moves back to cross the Equator (0∘0^\circ) heading southward.
After the June solstice, the apparent position of the overhead sun recedes southward.
4
Identify the final solstice position completing the cycle.
Around December 21 (December Solstice), the subsolar point reaches its southernmost limit at the Tropic of Capricorn (23.5∘S23.5^\circ\text{S}).
Earth reaches the opposite point in its elliptical orbit where the Southern Hemisphere tilts most toward the Sun.

Key Concept

Apparent annual movement of the subsolar point due to Earth's axial tilt (23.5∘23.5^\circ) and revolution around the Sun.
Rate this question

Topics

The Earth as a Planet and Earth Movements

More questions from this topic