Why do high altitude areas have brighter sunlight and lower temperatures as compared to the plains?

Why do high altitude areas have brighter sunlight and lower temperatur

1.	Why do high altitude areas have brighter sunlight and lower temperatures as compared to the plains?
Answer» High altitude areas have brighter sunlight because at high altitude there is a very low concentration of dust particles and atmospheric gases which absorbs the sunlight. There is a low atmospheric pressure at high altitudes. Lower atmospheric pressure results in lower temperatures at high altitudes.