Spanish Nights Getting Warmer

Because of the impact of extreme temperatures on agriculture and health in Spain, scientists at the University of Salamanca – USAL, have focused on the main causes of this phenomenon, hot days and cold nights between 1950 and 2006.

The new research, which was published by Climatic Change, actually analyzed the physical changes in the climatic extremes, or like Concepción Rodríguez, lead author of the study and a researcher at the General and Atmospheric Physics Department at the USAL, told SINC, “which changes are taking place in the air masses reaching the Iberian Peninsula, as well as sea temperature”.

The results show that in Spain, there is an increase in the warm days number, higher than for the rest of the world, accompanied by a decrease of the number of cold nights.

“The trend towards the reduction of cold nights correlates with that obtained at global level, according to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), however, the increase in warm days in mainland Spain is higher than the number obtained globally for the planet as a whole,” explained Rodríguez.

Most climate studies have focused on changes experienced at a global scale, and not on climatic extremes and the variations in the lowest and the highest temperatures, in hot days and cold nights.

The team also found an explanation to this phenomenon, by relating the increase in warm days with climate teleconnection indices, that show the oceanic and atmospheric characteristics.

“Warm days are related to atmospheric teleconnection patterns, while cold nights are caused, principally, by the temperature of the sea (in the North Atlantic)", said the researcher.

The hot days are caused by the hot air masses coming from northern Africa and “the type of weather that causes more cold nights is the depression over the Gulf of Genoa, which brings cold and dry air from central Europe to Spain.”

Rodríguez also said that this change in the number of warm days and cold nights is more obvious in the south west and north east of the Iberian Peninsula, and “one of the most probable causes of these changes is the variation in the surface temperature of the sea in the eastern Atlantic.”

The warm days increase is probably caused by human factors, according to the researchers.

The scientists presented their research last July, at the Congress on Statistics and Climatology in Edinburgh (Scotland).