two-stream approximation

The two-stream approximation is a method used in radiative transfer to model how light interacts with a medium, like Earth's atmosphere. It simplifies the complex behavior of radiation by dividing it into two directions: upward and downward. Instead of tracking every possible path, it estimates how much light is reflected, absorbed, or transmitted by considering these two streams. This approach makes calculations more manageable while still capturing essential details about how light moves through the atmosphere, useful for studying climate, weather, and remote sensing.