# Isentropic vertical coordinate

From AMS Glossary

## isentropic vertical coordinate

Vertical coordinate for atmospheric models defined as the potential temperature of the model atmosphere.

In practice the isentropic vertical coordinate is replaced by or changed gradually to a terrain- following coordinate near the ground; a change to pressure coordinates near the top of the model atmosphere has also been used.

*See*hybrid vertical coordinate, vertical coordinate system, pressure vertical coordinates.