Wind variability influencing wildfires in Spain

Terrestrial near-surface wind speed research (NSWS, at 10 m above ground)  has largely focused on the global-scale stilling phenomenon observed over recent decades. However, much less attention has been paid to whether this phenomenon is also present in the wind regimes associated with wildfire activity. In this context, the recently reported reversal of near-surface wind trends towards increasing wind speeds introduces additional uncertainty regarding the potential impacts of wind on global wildfire regimes.

In this study, we assess the ability of commonly used reanalysis products, such as ERA5 and CERRA, to represent observed wind variability at weather stations across the Iberian Peninsula for 1984-2021. According to our results, most reanalyses fail to reproduce the trends and multidecadal variability of NSWS observed at more than 700 weather stations. In contrast, the use of a high-resolution (3-km) NSWS dataset produced using a U-Net based on partial convolutions,  trained to reconstruct the wind field from station-based wind observations, better captures these temporal trends and variability. We then analyse the wind changes observed during wildfire events in Spain over recent decades, examining their relationship with large-scale climate oscillation modes. Finally, we explore whether observed trends in wildfire-related winds are consistent with the stilling–reversal framework.