# Pressure at ground level and at sea level

$1$atm $= 101325$pa
$1$bar $= 100000$ pa
$1$atm $= 1.013$ bar
$1$bar $= 0.987$atm

From wiki:

The bar is a metric (but not SI) unit of pressure exactly equal to $100000$ Pa.[1] It is about equal to the atmospheric pressure on Earth at sea level. Atmospheric pressure is the pressure exerted by the weight of air in the atmosphere.

My question: I presume ground level is higher than sea level. #Why is the pressure at sea level Less than at ground level?# I thought that since sea level is at a lower level, there will be a greater weight of air and hence higher pressure on it compared to at ground level

## my correction. I am sorry. Why is the pressure at sea level =1bar Less than at ground level=1atm, when supposedly there would be more air hence a greater weight of air hence a higher pressure?

• I'm not sure I understand the question - a bar is roughly one atmosphere (standard), which makes it a kind-of useful unit. Where is the ground level vs sea level coming from? – Jon Custer Dec 14 '15 at 19:00
• @Boomzxc - You are reading too much into that snippet from wikipedia. We happen to like powers of ten, and 100000 is about equal to 101325. That's all there is to it. – David Hammen Dec 15 '15 at 10:27