Modelling of phyto-toxic ozone doses for Norway: Based on chemical data assimilation

Phyto-toxic ozone dose (POD) is a term used to describe the uptake of the harmful gas ozone into the stomata of plants. POD-values over a certain threshold, Y, have been shown to cause reductions in biomass of crops and semi-natural vegetation. In this project we have used a version of the EMEP MSC-W chemical transport model which assimilates observational data of ozone and other compounds using a 3D Var assimilation system.
We show that the use of 3D-Var assimilation leads to markedly better reproduction of the daily ozone concentrations, and of the AOT40 metric (EU definition), at the Nordic sites.