http://www.engineeringtoolbox.com/density-air-d_680.html less dense than dry air http://www.engineeringtoolbox.com/density-air-d_680.html http://www.engineeringtoolbox.com/de...air-d_680.html decreases air density the density decreases http://www.engineeringtoolbox.com/de...air-d_680.html http://www.engineeringtoolbox.com/density-air-d_680.html http://www.engineeringtoolbox.com/de...air-d_680.html the density decreases decreases air density http://www.engineeringtoolbox.com/density-air-d_680.html