Recommended citation: Eiras-Barca, J., Corredoira-Iglesias, M., González-Cámara, L. T., Pérez-Alarcón, A., Nieto, R., Gimeno, L. (2026). Lagrangian and Eulerian Tracer-based Approaches to Heat Transport in Extreme Hydrometeorological Event. 8th MedCLIVAR Conference. Limassol, Cyprus, 21-35 September 2026.

Abstract

The frequency, intensity, and duration of extreme hydrometeorological events—particularly those involving both drought and heat waves or heat stress— have increased significantly in recent decades, posing substantial risks to societies and ecosystems worldwide, including, notably, the Mediterranean region. The research community has recently developed eulerian tracer-based and purely Lagrangian formalisms that enable the separation of the diabatic, adiabatic, horizontal, seasonal and pre-existing components associated with heat transport. The application of these methodologies provides valuable insights into the physical mechanisms responsible for the observed temperature anomalies. This preliminary study analyzes the insights these tools can provide for the study of extreme hydrometeorological events. In particular, an intense compound event of drought and heatwave that struck the Central and Southern Balkans and Greece in July 2012, and an intense heat stress event that affected the south-east of the Iberian Peninsula in Aug 2015 are analyzed using these Lagrangian and eulerian tracer-based formulations of heat transport. Preliminary results suggest that the temperature anomalies observed during the extreme heatwave in the Iberian Peninsula can be reasonably well explained by horizontal air mass advection. By contrast, the composite event (a combination of drought and a heatwave) in the eastern Mediterranean exhibits a far more intricate pattern, with the adiabatic, horizontal and vertical transport components each playing a role in explaining the observed anomalies.