On the Relation between Rainfall Intermittency and Physical Aridity

Código

I-EBHE0096

Autores

Annalisa Molini, Mijael Rodrigo Vargas Godoy, Yannis Markonis, Gabriele Villarini

Tema

WG 1.02: Decomposing Complexity

Resumo

Rainfall intermittency is a key feature of the hydrology of arid and semi-arid regions. In these climates, long droughts punctuated by short, intense rainfall events significantly impact landforms, ecosystems, and water security. Under climate change, intermittent precipitation patterns are predicted to become increasingly common across a broader range of climates. However, there is limited literature exploring the relationship between rainfall intermittency and physical aridity. At the same time, fine-scale representation of rainfall variability remains a major source of uncertainty in rainfall modeling and downscaling. Here, we examine the connection between rainfall intermittency, its temporal scaling laws, and aridity from a climatological perspective. We assume that intermittency is influenced by fine-scale processes, such as land-atmosphere interactions and local water and energy availability, as well as large-scale atmospheric forcing. Our analysis of extensive hourly and sub-hourly precipitation data sets from the Contiguous US (NOAA US-HPD) and Australia (Australian Bureau of Meteorology) reveals a well-defined functional relation between intermittency and aridity measures across a wide range of water-limited climates. These findings provide a basis for improving precipitation downscaling methods and gaining deeper insights into future precipitation patterns in water-limited regions.