Convective adjustment

From Glossary of Meteorology

convective adjustment

A method of representing unresolved convection in atmospheric models by imposing large-scale vertical profiles when convection occurs.

As originally developed, convective adjustment was applied when modeled lapse rates became adiabatically unstable. New temperatures were calculated for unstable layers by conserving static energy and imposing an adiabatic lapse rate. If, in addition, humidities exceeded saturation, they were adjusted to saturation, with excess water removed as precipitation. A related adjustment, (stable saturated adjustment), for stable layers with water vapor exceeding saturation, returned them to saturation, also conserving energy. More recently, convective adjustments have been developed that adjust to empirically based lapse rates, rather than adiabatic lapse rates, while still maintaining energy conservation. Convective adjustment is generally applied to temperature and humidity but, in principle, can also be applied to other fields affected by convection.