Answer to Question 1
Troposphere, stratosphere, mesosphere, and thermosphere. They are defined by the inflection points (maxima and minima) of the vertical temperature profile. The troposphere extends from the surface up to 10 to 15 km (higher in the tropics, lower near the poles). The stratosphere, which is located from about 10 to 15 km to 50 km above the surface, where temperature increases with altitude. Above the stratosphere, temperature decreases with altitude in the mesosphere (from about 50km to 90 km) and then increases once again in the uppermost layer, the thermosphere (above about 90 km).
Answer to Question 2
Heat energy can be transferred by three different mechanisms: convection, conduction and radiation. Convection and radiation are important in Earth's global energy budget.