Is temperature increases as altitude increases because you are moving closer to the sun?

No, temperature does not increase with altitude because you are moving closer to the sun. In the Earth's atmosphere, temperature generally decreases with altitude in the troposphere due to the decreasing pressure and density of air. The sun's heat primarily warms the Earth's surface, and as you go higher, there is less air to retain that heat. However, temperature can increase with altitude in the stratosphere due to the absorption of ultraviolet radiation by the ozone layer.