Modelling of heterogenous chemistry in the stratosphere.

Abstract

A photochemical trajectory model for the stratosphere has been employed at NILU over several years. The model is made up of coupled modules describing atmospheric processes. This report gives a description of the modules and how the processes are parameterised.

In this study, the model has been applied as a box model in order to study in-situ chemical processes and ozone loss at middle and high northern latitudes in the lower stratosphere. The impact of heterogeneous chemical reactions facilitated by liquid sulphuric acid particles has been investigated. Two different scenarios for particle abundance have been used. The effect of well-established heterogeneous reactions on the partitioning of species, ozone loss mechanisms and ozone depletion rates is examined. In addition, some proposed reactions are studied. The difference in ozone column loss has been calculated.