1,2,1,2,3- 1Institute of Geo‐Hydroinformatics, Hamburg University of Technology, Hamburg, Germany
- 2United Nations University Hub on Engineering to Face Climate Change at the Hamburg University of Technology, United Nations University Institute for Water, Environment and Health (UNU-INWEH), Hamburg, Germany
- 3United Nations University Institute for Water, Environment and Health (UNU-INWEH), Richmond Hill, Ontario, Canada
- 4Department of Civil and Environmental Engineering, University of California, Irvine, California, USA
- 5Department of Earth System Science, University of California, Irvine, California, US
Soil moisture plays a key role in land-atmosphere interactions by influencing components of the land surface energy balance. It is highly sensitive to variations in groundwater levels, particularly in shallow aquifers where changes in water availability can alter soil moisture dynamics and thus surface fluxes (Vogelbacher et al., 2024). Ongoing declines observed in many of the world's major aquifers (Jasechko et al., 2024) therefore raise questions about potential shifts in soil moisture regimes and their implications for land-atmosphere interactions. In this study, we investigate how aquifer states (i.e., deepening, shallowing, or remaining stable) affect water vapor and heat exchanges between land and atmosphere by focusing on variations of evaporative and sensible heat fluxes. We relate these shifts to extreme heat variations using summer heatwave frequency as a proxy. Our approach integrates groundwater model outputs with in situ measurements over a 16-year period (2000 to 2015) to identify the dominant response variable for each aquifer by calculating correlations between the aquifer trend and environmental variables (e.g., soil moisture, evaporation, soil temperature). Our findings indicate distinct correlation patterns across deepening and stable aquifers, emphasizing the importance of incorporating groundwater dynamics into assessments of soil-moisture temperature feedback and heatwave risk (Vogelbacher et al., 2026). In this context, improved understanding of groundwater land-atmosphere interactions can inform integrative management frameworks that balance hydrological functioning, ecosystem resilience, and human well-being.
References:
Jasechko, S., Seybold, H., Perrone, D., Fan, Y., Shamsudduha, M., Taylor, R. G., Fallatah, O., & Kirchner, J. W. (2024). Rapid groundwater decline and some cases of recovery in aquifers globally. Nature, 625 (7996), 715–721. https://doi.org/10.1038/s41586-023-06879-8
Vogelbacher, A., Aminzadeh, M., Madani,K., Shokri, N. (2024). An analytical framework to investigate groundwater‐ atmosphere interactions influenced by soil properties. Water Resources Research, 60, e2023WR036643. https://doi.org/10.1029/2023WR036643
Vogelbacher, A., Afshar, M. H., Aminzadeh, M., Madani, K., AghaKouchak, A., & Shokri, N. (2026). A global analysis of the influence of shallow and deep groundwater tables on relationships between environmental parameters and heatwaves. Environmental Research, 289, 123354. https://doi.org/10.1016/j.envres.2025.123354
How to cite: Vogelbacher, A., Aminzadeh, M., Madani, K., AghaKouchak, A., and Shokri, N.: How groundwater trends modulate soil moisture feedback and summer heatwave frequency, EGU General Assembly 2026, Vienna, Austria, 3–8 May 2026, EGU26-1133, https://doi.org/10.5194/egusphere-egu26-1133, 2026.
