When the barometric pressure is given for Denver, is that the actual pressure or is it corrected to sea level by some formula?
The pressure reported for Denver, or any official observation station for that matter, is not the actual pressure on the surface, but rather is the pressure corrected to sea level. The reason this is done is so that meaningful maps of constant pressure lines, called isobars, can be drawn for stations across the USA. These maps are useful for picking out areas of relative high and low pressure. If pressure readings were not corrected, places like Denver would almost always have lower pressure than spots at lower elevations. Essentially, the map would reflect topography, rather than weather systems in the atmosphere. Learn more about air pressure on this USA TODAY resource page.
