Date and time: 11th June 2025; 2:00 – 2:45 PM (CET) – Understanding the effect of wind-induced pressure fluctuations on gas exchange at a snow-covered boreal forest
The CLEANFOREST webinar series is hosted by COST Action’s Young Researchers community for all interested researchers and practitioners, usually during the second and fourth week of every month. We are honored to announce that for the twenty-fourth event in the series, we will be joined by Toprak Aslan from the University of Münster, Germany, one of the CLEANFOREST STSM Grantees.
A short summary of his talk is given below.
Snow-covered soils can store a large amount of CO2 due to their porous structure. It is often assumed that CO2 produced by roots and microbes is exchanged with the atmosphere via diffusion. However, this assumption does not hold for high-wind speed conditions. This is because high-wind conditions cause high-frequency pressure fluctuations that flush the stored CO2 out, a process called “pressure pumping”. Such non-diffusive fluxes are naturally not associated with typical drivers of biological activity (e.g., soil temperature), however, they are still included in partitioning and modelling procedures. As a result, in low wind conditions or when the stored CO2 is depleted, such an erroneous modelling procedure likely overestimates respiration, ultimately affecting the carbon budget.
In the Kenttärova forest site located in the sub-arctic region of Finland, we have more than two decades of eddy covariance measurements, monitoring CO2 and energy fluxes at the ecosystem level. To better quantify the exchange processes, we wanted to clarify the potential effect of pressure pumping. Therefore, in December 2024, we implemented low-cost pressure sensors sampling at 10Hz at multiple heights in addition to CO2 concentration measurements at multiple depths in snow. In this seminar, I will summarize what we have learned so far from this experiment.
Deadline: please sign up via the registration link above BEFORE the webinar.
Contact:
- Presenter: Toprak Aslan toprak.aslan@helsinki.fi
- Webinar convenor: Andrei Popa popa.andrei.dorna@gmail.com
- Webinar co-convenor: Jakub Jelen kuba.jelen@wp.pl