> For the complete documentation index, see [llms.txt](https://swatplus.gitbook.io/io-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://swatplus.gitbook.io/io-docs/introduction-1/channels/nutrients.cha/air_rt.md).

# air\_rt

If routing is performed on an hourly time step, the units of **air\_rt** are converted to 1/hr by the model.