How do sunrise and sunset times change with altitude?
Hi, I am a professional airline pilot and an amateur astronomer and would appreciate it if could provide me with a formula or method in how to calculate the affect of altitude on sun set/rise at different latitudes and if there is any way to predict time of sun set/rise while flying. At most latitudes on the Earth, the effect of increased altitude is the same: it makes the Sun rise earlier and set later than it would at that same location from the ground. To make things simple, let’s assume that you are in a plane over the ocean, at the equator at sunset. In that case, straightforward trigonometry indicates that at a typical commercial airplane altitude of 12000 metres, you can see an extra 2 degrees “around” the Earth. Since the Earth moves around the Sun at a rate of a quarter of a degree a minute, it means that at this altitude, sunset occurs 8 minutes later than it would from the ground. The variation with altitude is approximately linear, and so we conclude that sunset is later by
