Standard altitude-pressure tables allow mountaineers and ... the density of air decreases. Temperature also changes the density of air. As air gets warmer it expands and becomes less dense ...

Because Earth rotates, these upper-altitude winds blow from west ... In between these low-pressure and high-pressure systems is a strong change in pressure over a distance—a pressure gradient.

Back home after his trip, he built this simple Temperature, Altitude and Pressure Display Device using a few off the shelf parts. Following a brief search, he zeroed in on the BMP 180 sensor ...