Characterization of summer easterly winds over the inner Iberian Peninsula

Abstract

In summer, a humid and relatively intense easterly regional wind appears in the Inner Plateau of the central Iberian Peninsula. It is known as Solano in some regions, has great ecological and cultural importance in these areas and has also been associated with flows in the northern regions. In this work, a first quantitative definition of this regional wind is proposed based on wind direction and speed and humidity gradient thresholds both in the central and the northern Iberian Peninsula. COSMO-REA6 high-resolution reanalysis has been used to describe the main statistical features of this wind. Its validation, comparing it with observational data, concluded that the reanalysis describes sufficiently well the wind and humidity of the study area in the chosen period. Solano appears in the central region around 41% of all July and August days (1995–2018 period), and in 73% of those days it is also detected in the northern Iberian Peninsula. It adopts an easterly direction, reaches speeds >3 m/s and causes a humidity variation. Solano presents large interannual variability, happening between around 30–60% summer days per year. It also has a marked daily cycle as it appears in the morning, spreads throughout the territory and disappears at night. Finally, this flow frequently occurs accompanied by low pressure conditions in the center-west of the Peninsula. In the northern region other easterly wind flows that do not seem related to the low pressure system or to Solano are also detected.