27 October 2017
The satellite images you see on TV every day are usually from the new GOES-16 which is way up there, at a tenth of the distance to the Moon! But there are other weather satellites you probably don’t know about in polar orbit that are just as important. These satellites have instruments that can measure winds/ temperatures and moisture at many different levels as they fly over the poles, and without them 5-7 day long range forecasts would not be possible.
To run an accurate global weather model, you MUST give it a good idea of the current state of the atmosphere, and polar-orbiting satellites fill the ocean data void by taking hundreds of measurements over oceans and remote land areas. All of this data this is all fed into global weather models and as a side benefit forecasters in the far north and south can see satellite imagery that the equator based GOES images cannot see well.
The polar-orbiting satellites are only 800 km high and are in what is called a sun-synchronous orbit which means they pass over the same region about the same time, twice each day, once going north and once going south! Just like GOES-16 was a new 21st-century satellite, the new 21st-century next-generation polar weather satellite is about to launch. JPSS-1 is set to go up on November 10, and it has new and improved instruments to sample the atmosphere at many levels. It also has an instrument called VIIRS that is already on the Suomi satellite. This imager sends back amazing full-colour images of Earth (See one below from today).