La excepcional ola de frío tras la depresión Filomena. Análisis del balance de energía superficial y de los procesos de microescala asociados

Abstract

During January 11-18 2021, the interior of Spain was affected by one of its most extreme cold waves in this century. This event followed historical snowstorm Filomena, with snow accumulations of 30-50 cm in the interior of the country. This study aims at analysing the physical processes leading to the extreme cold temperatures close to the surface, analysing the contribution of the different scales, namely the synoptic and microscale. It is found that the cold wave was not driven by cold wave advection, as is usually the case in Iberia. Stable synoptic-scale conditions enhanced the contribution of the microscale. The study of the microscale processes is carried out by means of analysis of in-situ data from a micrometeorological station at a rural area in the Community of Madrid. Results from this part show that surface albedo incremented from 20% to 80%, leading to a reduction in the net radiation available at the surface, subsequently impacting the sensible, latent and ground heat fluxes. The study proves to contribute to the understanding of the physical processes associated.