What gases are in the atmosphere as altitude increases?

As altitude increases, the composition of the atmosphere remains largely the same, primarily consisting of nitrogen (approximately 78%) and oxygen (about 21%). However, the density of these gases decreases, leading to a reduction in their partial pressures. Additionally, trace gases like argon, carbon dioxide, and water vapor also decrease in concentration with altitude. Overall, while the types of gases remain consistent, their amounts and pressures diminish as one ascends into the atmosphere.