Aucky - surface pressure is due to the weight of air above it squashing it down against the surface of the earth. Variations in surface pressure are due to variations in surface temperature which cause pressure differentials at altitude leading to air moving from high to low (pressure and temp) at altitude which redistributes the air giving variations in the quantity of air above differewnt points on the surface. This is why the tropopause is higher at the equator and lower at the poles and is where all thermal winds originate.
there is an obvious downwards flow of air, that undoubtedly builds an area of higer pressure beneath the disc in proximity to the ground, because it's flow is restricted
this is exactly the urban myth that Nick and others have tried to dispel - it is a popular notion because it seems intuitive and is easy to understand - doesn't make it right though.