Answer to Question 1
B
Answer to Question 2
Earth's heat budget is fueled by the sun's energy. On an average day, about half of the solar energy that reaches the upper atmosphere is absorbed at Earth's surface. This heat is not evenly distributed, however. Sunlight striking polar latitudes spreads over a greater area and reflects back to space more than sunlight striking the tropical latitudes does. This is due to differences in the angle that the sun's rays strike Earth in these areas-the sunlight strikes polar regions at a low angle, and it strikes tropical regions at a near-vertical angle. The tropical regions, therefore, receive more radiation than they re-radiate (or reflect), causing a surplus. The polar regions re-radiate more radiation than they receive, causing a deficit. However, ocean currents and air masses move excess heat from the tropics toward the poles, helping to equalize the heat imbalance. Over long periods of time, the total incoming heat equals the total heat radiating into space, making Earth, as a whole, in thermal equilibrium.
Boreal forests, such as this one in Siberian Russia, are dominated by a few species of conifer trees
Mountain Glaciers
The melting of glaciers and ice sheets is making an increasing contribution
Glaciers
Wave Refraction
A wave whose wavelength is 0.500 m is traveling down a 500-m long wire whose total mass is 25 ...