Assessment of isoprene and near-surface ozone sensitivities to water stress over the Euro-Mediterranean region

Our paper on the impact of water stress on isoprene emissions and near-surface ozone levels over the Euro-Mediterranean region has been published in Atmospheric Chemistry and Physics.

Using a regional climate-chemistry model (RegCM4chem) coupled with a land surface model (CLM4.5) and a biogenic emission model (MEGAN2.1), we assessed that water stress reduces isoprene emissions on average by nearly 6% over the Euro-Mediterranean region, with larger effects (between −20 % to −60 %) during the warmest and driest summers and over large isoprene-source areas (e.g., the Balkans).

Sustained decreases in isoprene emissions co-occur with negative anomalies in precipitation, soil moisture and plant productivity, and also happen after prolonged or repeated dry anomalies. Although the decrease in isoprene emissions due to water stress may be important, it only reduces near-surface ozone levels by a few percent due to a dominant VOC-limited regime over southern Europe and the Mediterranean Basin.

However, the choice of the parameterization to reproduce the effect of soil moisture on isoprene emissions influences the pattern and the magnitude of changes in isoprene emissions and near-surface ozone levels.

If you want to read more, follow the link or drop me an email:
https://acp.copernicus.org/articles/23/13301/2023/acp-23-13301-2023.html