Levante and Poniente winds in the Strait of Gibraltar: Present and future characterization using regional climate models

Abstract

Levante and Poniente are regional winds that appear in the Strait of Gibraltar with great intensity and frequency. However, they have not been the focus of many modelling studies so far. For this reason, the present work has two aims. First, to evaluate the capability to describe both winds using the largest available set of outputs from regional climate models and different wind data frequencies, spatial resolutions and atmosphere-ocean coupling characteristics. Second, to study wind changes between present (1950–2005) and future climate conditions (RCP8.5, 2006-2099). Results indicate that available spatial resolution is essential for a proper wind description. Internal physics are also a source of variation. Coupling effect does not lead to important changes on any of the studied regional winds. Levante occurs in the historical period between 110–130 days per year, covering 42%–44% of the Strait, with future increase of 10–20 annual events, depending on the model. Levante spatial extension varies with mixed trend signs. Poniente is detected between 135–155 days per year over 45%–50% of the Strait for the historical period and shows future debilitation in its magnitude with around 5–20 less days. This pioneering work manifests the capability of regional climate models to quantify Levante and Poniente events. Future climate change projections should be further studied to obtain as much regional climate model outputs as possible and to increase the robustness of such projections. Besides, a deeper analysis of weather variability patterns related to these wind conditions would strongly increase our understanding of the atmospheric mechanisms behind such important regional winds.