Why is the air pressure on Venus so high? (Revised)
The temperature of Venus is 462 degree C, less than three times of the earth’s temperature, in Kelvin. The radius of Venus is slightly smaller than the earth’s. The density of Venus is slightly less than the density of the Earth. But the atmosphere pressure is ninety times higher. How is it possible?
The state equation of ideal gas is PV = nRT. Ignoring the constant R, the equation can be rewritten as P = (n/V)T. n/V, the density of the gas should be determined by the gravitational force. The gravitational forces are similar on Venus and the earth. Venus barely rotates. Earth rotates. Its centrifugal force is about 0.5% of the gravitational force at equator. We can ignore rotation for the moment. Air density might be similar on Venus and Earth. When T is three times higher, we might estimate P is roughly three times higher.
What is wrong with my reasoning? I could not understand why the atmosphere pressure is so high on Venus.
Reference for relevant data
https://scitechdaily.com/from-temperate-world-to-acidic-hothouse-how-massive-volcanism-may-have-altered-venus-climate/