An updated review on recent trends in observational surface atmospheric variables and their extremes over Spain

This article reviewed state-of-the-art findings on recent trends in observed atmospheric variables and their extremes in Spain. Our study screened peer-reviewed articles, published within the last decade, on recent climate variability in Spain, with a particular focus on a range of the essential atmospheric variables. The review focusses on the recent evolution of precipitation and air temperature, but also on other meteorological variables such as solar radiation, wind speed, surface humidity and evapotranspiration. While this review highlights results on changes in the mean state of climate in Spain, it also gives equal attention to findings on extreme weather events (e.g. rainstorms, heat waves and droughts). This paper also reviews trends of the most extreme events, like rainstorms, heat waves and droughts. A detailed review of studies focusing on recent changes in the surface climate of Spain revealed some key findings. Studies demonstrate an overall increase of solar radiation since the 1980s. A similar behaviour was observed for surface air temperature since the 1960s, on the order of +0.3ºC decade-1, with rapid warming rates during summer. Different seasonal trend patterns of wind speed were noted over Spain, with declines in winter-spring and increases in summer-autumn. A remarkable decrease (-5%) in relative humidity was observed from 1961 to 2011. For precipitation, studies suggested a strong variability over both space and time, with a moderate decrease of the annual total precipitation. In accordance with changes in the mean conditions of climate, studies of extreme weather events stressed a notable warming in warm extremes, while changes in cold extremes were generally insignificant.This word was supported by the research project PCIN-2015-220, CGL2014-5235-C03-01, Red de variabilidad y cambio climático RECLIM (CGL2014-517221-REDT) financed by the Spanish Commission of Science and Technology and FEDER, "LIFE12 ENV/ES/000536-Demonstration and validation of innovative methodology for regional climate change adaptation in the Mediterranean area (LIFE MEDACC)" financed by the LIFE programme of the European Commission, and IMDROFLOOD finaced by the Water Works 2014 co-funded call of the European Commission