Earlier today I was curious about barometer readings at various elevations, thinking that they would more or less follow a standard pressure-altitude chart like this one. With my lifelong casual interest in aerospace you’d think I would have looked into this already. As it happens, though, I just learned yesterday that my smartphone has a barometric sensor in it, and that’s probably what spurred me on to find out about it.
Link.
According to Wikipedia, the Peruvian mining town of La Rinconada is the world’s highest human habitation, with an elevation of over 16K feet. The chart I linked to indicates that the atmospheric pressure at that altitude is just barely over half the pressure at sea level, but based on the weather sites and my smartphone app, the atmospheric pressure as of a few minutes ago is around 29.5in, or 1008mb.
How is this possible? Do meteorologists use some sort of standard normalization formula to make the resulting numbers appear as if every city on Earth were at sea level?
Or is it there a standard way that barometers are calibrated for different altitudes? What would happen if I carried my own barometer to Lhasa or La Rinconada? Would the readings be way, way below the part of the scale labeled “Stormy”, “Changeable”, and “Fair”?