Summary
We have added calculations of PODY for birch, spruce, wheat and potato to the MATCH-Sweden system. Several important updates compared to the previous implementation for generic crops and generic deciduous trees have been made including improved calculations of canopy level ozone concentrations, updated calculations of quasi-laminar and surface resistance and inclusion of soil moisture dependence for specific vegetation species.
A comparison to results from the EMEP model for generic crops and generic deciduous trees shows a better agreement than previously. Considering also that an error in the EMEP calculations has been identified, affecting primarily the PODY calculations for generic deciduous trees, MATCH-Sweden and EMEP model results now appear to be more consistent.
Year to year variability of PODY for birch and spruce are similar to that for generic deciduous trees while numerical values are different, especially for birch, due to different parameters in the PODY calculation and longer vegetation periods. Critical levels corresponding to a 4 % growth reduction are exceeded for both birch and spruce in major parts of Sweden for all years in the period 2013-2017.
Year to year variability of PODY for wheat and potato are larger than for generic crops due to the higher threshold for PODY used in the calculations. Critical levels corresponding to a 5 % reduction in crop yield are reached in four of five years in southern Sweden for wheat and for two in five years for potato.
The updated program package for PODY calculations could be used to calculate consistent time series of PODY for different types of vegetation for the period 1990-2013 based on reanalyzed ozone concentrations. The program package could also be developed to calculate PODY for the whole of Europe for different emission- or climate scenarios.
The results presented in this report are also available in digital form at the SMHI home page for environmental monitoring of air quality (www.smhi.se/klimatdata/miljo/atmosfarskemi).