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.
By reflecting most visible light, snow creates a much cooler microclimate than nearby bare ground.
Wave
P wave (SA node initiates atrial depolarization).
Wave Basics
A student creates a new blog about chemistry.
How to impress a choosy female: Male fiddler crabs (top) wave their one enlarged claw to a attract a