Earth's energy balance and albedo

Grade 9 Science Worksheet

Circle the best answer.

1. Read this first

   Albedo (NSIDC)

   Surface	Albedo
   open ocean	about 0.06
   bare sea ice	0.5 to 0.7
   snow-covered sea ice	up to 0.9

2. 1.

   200 W/m² of sunlight hits snow-covered sea ice with albedo 0.9 (NSIDC). How much is absorbed, by Bo's math?

   • About 0.9 W/m²
   • About 180 W/m²
   • About 200 W/m²
   • About 20 W/m²
3. 2.

   The same 200 W/m² hits open ocean with albedo 0.06 (NSIDC). How much is absorbed, by Esme's math?

   • About 140 W/m²
   • About 188 W/m²
   • About 12 W/m²
   • About 194 W/m²
4. 3.

   Bare sea ice reflects 50 to 70% (NSIDC). Of 200 W/m², how much does it absorb, as a range, by Jun's math?

   • About 130 to 150 W/m²
   • About 100 to 140 W/m²
   • About 60 to 100 W/m²
   • About 50 to 70 W/m²

5. Earth's energy budget (NASA)

   Part	Share of incoming sunlight
   reflected to space	29%
   absorbed by the atmosphere	23%
   absorbed by the surface	48%

6. 4.

   NASA: 23% is absorbed by the atmosphere and 48% by the surface. What total share does Earth absorb, by Milo's math?

   • About 29%
   • About 100%
   • About 25%
   • About 71%
7. 5.

   Earth absorbs about 71% of incoming sunlight (NASA), yet its average temperature stays steady. Why, by Noah's reading?

   • It stores the energy with no loss
   • It radiates an equal amount of heat to space
   • The absorbed energy disappears
   • It reflects 71% instead
8. 6.

   Sunbeams striking the equator straight on and the poles at a slant. NASA: the Sun delivers about 1,360 W/m² to a surface facing it, yet the average at the top of the atmosphere is about 340. Why one-fourth, by Pia's reading?

   • Earth is four times farther from the Sun
   • Clouds block three-fourths of it
   • Half of Earth is dark, and sunlight strikes the sphere at an angle
   • Albedo removes three-fourths of it
9. 7.

   What is 1,360 W/m² divided by 4 (NASA's planet-wide average), by Ren's math?

   • 340 W/m²
   • 5,440 W/m²
   • 34 W/m²
   • 1,356 W/m²

10. Use this

    Sunbeams striking the equator straight on and the poles at a slant.

11. 8.

    NASA: in summer, bright snow and sea ice at the poles reflect much of the light. What does that do to polar heating, by Tala's reading?

    • It has no effect
    • It lowers how much solar energy is absorbed there
    • It raises the heating there
    • It moves the poles closer to the Sun
12. 9.

    NASA: 45° gets about 70% of the equator's energy. If the equator gets 400 W/m² at noon (model), about how much does 45° get, by Zee's math?

    • About 120 W/m²
    • About 280 W/m²
    • About 360 W/m²
    • About 470 W/m²
13. 10.

    Why does Earth's tilt of about 23° cause seasons, by Ari's reading (NASA)?

    • Earth moves much closer to the Sun in summer
    • The poles swap places
    • The tilt changes the ocean's albedo
    • Each hemisphere in turn gets more direct sunlight and longer days