(b) what is the mass of the atmosphere above 500hPa? you can again assume a sphere of radius 6400km for this calculation. what fraction of the mass of the earth's atmosphere lies above 500 hPa?
(c) repeat (b) for the 250hPa surface.
a) assuming an average sea-level pressure of 1000hPa, what is the mass of the atmosphere? assume that the earth is as sphere with radius 6400km.
Surface area of the earth = 4pi*r^2 = ...