Blowing away the fog of ignorance. | Old Weather
One of our main aims, for the weather observations recovered by the project, is to improve our reconstructions of past weather conditions, and we want to reconstruct not just the surface pressure, sea and air temperatures, wind speed and direction, that we are digitising from the logs, but the complete state of the atmosphere. This will give us air temperatures and movement (both at the surface and higher up), clouds, rainfall, humidity … Remarkably, we can do this – meteorologists have built sophisticated computer models of the atmosphere, and we can use these models to calculate the complete state of the atmosphere just from our limited set of surface measurements. This is not easy to do, but we’ve a lot of experience doing it, because this is how weather forecasts are made: collect observations of present weather, use a computer model to synthesise those observations into a representation of the state of the whole atmosphere, run the models forward from that state to see what will happen tomorrow.
