Question

1. Would Santa Clarita (latitude 34^oN) ever receive direct, vertically overhead rays of the sun? Why or why not?

2. Why does the Equator get 12 hours of day and 12 hours of night, every day of the year, and all other latitudes do not?

3. On the June solstice, why does the area between the Arctic Circle (66.5^oN) and North Pole (90^oN) have 24-hour daytime, whereas the area between the Antarctic Circle (66.5^oS) and South Pole (90^oS) gets 24-hour nighttime?

4. Would Istanbul, Turkey (41^oN) ever get 12 hours of night in July? Give at least 2 accurate reasons for your answer.

5. Define aphelion and perihelion What are their dates? Why don’t they have any effect on our seasons?

Answer 1

1. No. Earth has an axial tilt of 23.5^o, therefore only those latitudes lie in between 23.5N and 23.5S will receive vertically overhead rays of the Sun with the revolution of the earth. During northern/southern hemispheric summer northern/southern hemisphere is inclined towards the sun. Once Sun's vertical rays reach 23N/23S then it starts to move backwards.

2. Due to the axial tilt of the earth, each hemisphere will move nearer and fartherer from the sun but the equatorial region will stay in the same position relative to the sun. So there won't be much noticeable change in the duration of day and night in the equatorial region. Change in the day-night duration occurs with the migration of the circle of illumination with the revolution of the earth.

3. On the June solstice, Northern hemisphere is inclined towards the Sun. So the circle of illumination will not reach the antarctic circle. Because of that area below antarctic circle experiences 24 hr night in June solstice. But on the same time entire north pole falls in the circle of illumination, so it will not get out of the circle of illumination with the rotation of the earth. So arctic circle experiences 24 hr day in June solstice.

4. No.

1. The northern hemisphere is inclined towards Sun.
2. Aphelion

5. Aphelion is the point in Earth's orbit at which it is farthest from the sun whereas perihelion is the closest point. This arises because of the elliptical shape of Earth's orbit. Since seasons are controlled by earth's axial tilt and revolution of the earth, aphelion and perihelion don't have any effect of seasons.