  == Why sky blue ==  Sunlight scattered by gases with very negligible intensity because according to Rayleigh scattering particles range between 30 and 40 nanometers are trillion times more intense than gases ( nitrogen & oxygen ) and much less intense than haze ( about 200 nanometers ). On the other side tiny particles and haze appear white in cold weather, which means that atmospheric blue color is Rayleigh scattering independent.   It is more easy to explain in my mother language as shown in this link  http://www.kabel.0fees.net/Sky/Sky-color-is-unknown.htm   that ozone layer reflects ocean's color