Lecture Quiz Review Autumnal Equinox (Fall) – September 21 1. On the diagram to the right, label the following positions where the Earth is located in its orbit around the Sun: a. Fall, winter, spring, summer (Northern Hemisphere) b. The approximate dates for these locations. Winter Solstice Summer Solstice c. Where the Earth is orbiting the Sun: December 21 June 21 (F) Faster Perihelion Aphelion (S) Slower Faster Slower (P) Perihelion Sun (A) Aphelion

2. The tilt of the Earth accounts for the change of Seasons. Why is this so?

The location where the sun is perpendicular to the Earth’s surface changes throughout the year. When the sun’s rays are Vernal Equinox more vertical, the intensity of the light is greater and the heating effect (Spring) – March 21 is greater. At more northerly latitudes the sun’s rays are more oblique to the Earth’s surface and the intensity is less and the heating effect is less.

3. Bob says, “The seasons are a quarter of an orbit”, Suzy says, “The seasons are a quarter of a year.” Who’s right? How do you convince the other they are wrong?

The seasons are a quarter of an orbit. If they were a quarter of a year the seasons would be equal in length, which they are not. Winter is the shortest of seasons and summer the longer of the seasons. The Earth is traveling faster in the winter so the gravitational attraction between the sun and the earth must be greater. Thus the sun and earth are closer during the winter than during the summer months.

4. Then, Bob says, The Earth is closer to the sun in the summer which explains why the Earth is warmer.” Suzy says, “If that is true, then why does the Southern Hemisphere have winter when we have summer? Aren’t they closer to the sun too?” Please settle this argument.

Suzy is correct. The whole planet would be closer, both Northern and Southern Hemisphere so if distance were a factor, what is true for the Northern Hemisphere must also be true for the Southern Hemisphere.

5. The latitude of Oslo Norway is 60o N. What is the altitude of the Sun during: Winter Solstice Summer Solstice 30o – 23o = 7o 30o + 23o = 53o

6. The latitude of Dallas, TX is 33o N. What is the altitude of the sun during: Winter Solstice Summer Solstice 57o – 23o = 34o 57o + 23o = 80o

7. Guam is a territory of the United States located in the Western Pacific Ocean at a latitude of 13o N. What is the altitude of the sun on the summer solstice?

77o + 23o = 100o. This is equal to 80o above the northern horizon.

8. Name the 5 major lines of latitude, give their latitudes, and briefly describe their significance. Line of Latitude Latitude Significance Mid-point between the poles. Sun is directly overhead at Equator 0o the equinox. Tropic of Cancer 23o N Sun is directly overhead at the summer solstice (N. Hem.)

Tropic of Capricorn 23o S Sun is directly overhead at the summer solstice (S. Hem.)

Arctic Circle 67o N Locations north experience polar day/night.

Antarctic Circle 67o S Locations south experience polar day/night.

9. Name the 2 major lines of longitude, give their longitudes, and briefly describe their significance. Line of Longitude Longitude Significance Prime Meridian 0o Separates East and West longitudes. International Date Line 180o Establishes the beginning of the calendar day.

10. The circumference of the earth is approximately 40,000 km. A globe I have has is one meter around at the equator. According to this scale, 1 cm on the globe is equal to how many kilometers on earth?

40,000 km / 100 cm = 400 km / 1 cm

11. Communication satellites orbit the earth at a height of approximately 500 km above the surface. Using the scale of my globe, how many centimeters above the surface is the satellite orbiting?

400 km / 1 cm = 500 km / 1.2 cm

12. It is 1:00 pm on Wednesday in Providence. What day and time is it in the following locations?

Location Latitude Longitude Time Day Prague, Czech Republic 50o 05’ N 14o 25’ E 7 pm Wednesday Kuala Lumpur, Malaysia 3o 08’ N 101o 42’ E 1 am Thursday Anchorage, Alaska 61o 13’ N 149o 54’ W 8 am Wednesday

13. When traveling westward across several time zones, do we set our clocks ahead or behind our current time? Behind

14. When traveling westward across the International Date Line, do we set our calendars ahead or behind our current day? Ahead

15. What can be said about the number of daylight hours for any latitude at the equinoxes? Same, 12 hours.

16. During the summer months, what can be said about the number of daylight hours a location experiences as the latitude increases?

Further north the longer the days in the summer and longer the nights in the winter.

17. Providence receives 16 hours of daylight near the summer solstice. How many hours of daylight does Providence receive near the winter solstice? 8 hours

18. What determines if a location will experience a polar day or night? When do these locations experience a polar day and when do they experience a polar night? North of Arctic Circle, or South of Antarctic Circle.

Barrow, Alaska, experiences polar days during the summer months and polar nights during the winter months.

19. What determines if a location will experience the sun directly overhead at some point during the year?

Must be within the tropics, 23o north of the equator or 23o south of the equator.

20. If the tilt of the Earth’s axis was 40o instead of 23o, how would this increased tilt affect the Earth’s climate?

The seasonal effects would be greater. For a location like Providence, we would have summers like Miami and winters like Fairbanks.

21. If the tilt of the Earth’s axis was 10o, how would this decrease in tilt affect the Earth’s climate?

The seasonal effects would be less. There would be less variation in the hours of daylight during the year and thus a smaller change in temperature from season to season. Locations like Fairbanks would be very cold year long.

22. In which direction (clockwise or counter clockwise) does the Earth rotate on its axis? In which direction (clockwise or counter clockwise) does the Earth orbit the Sun?