A global Lagrangian analysis of near-surcface warm and cold temperature extremes

Temperature extremes have a substantial impact on society and the environment, however a full physical understanding of their formation mechanisms is still lacking. In particular, the relative importance of the three key processes – horizontal temperature transport, subsidence accompanied by adiabatic warming, and diabatic heating – is still debated. Here, we present a global quantification of the contributions from these processes to near-surface warm and cold extremes using the Lagrangian framework. To this end, we apply two different Lagrangian temperature anomaly decompositions: one based on the full fields of the respective terms, and the other one based on the anomaly fields of the respective terms (i.e., deviations from their corresponding climatologies). We will show that the results from the full-field decomposition mostly align with those of a previous study, while the anomaly-based decomposition offers a completely new assessment of the roles of the different processes, especially with regard to warm extremes.