Climate Change Accelerating Destructive "DANA" Phenomena

Natural disasters are increasing at an alarming rate, much to people's concern. The catastrophic floods that killed at least 72 people in Spain were caused by a destructive weather system in which cold and warm air meet to produce heavy rain clouds, a pattern that risks becoming more frequent as climate change continues. The phenomenon is known locally as "DANA," a Spanish acronym for isolated high-altitude depression (depresion aislada en niveles altos). Unlike regular storms or gales, it can form independently of the polar or subtropical jet streams. When cold air blows over the warm waters of the Mediterranean, the warmer air rises quickly and forms dense, water-laden clouds that can remain over the same area for hours, increasing their destructive potential. According to meteorologists, this phenomenon sometimes causes large hail and tornadoes, as happened this week. Eastern and southern Spain are particularly prone to this phenomenon due to their location between the Atlantic Ocean and the Mediterranean Sea. Warm, humid air masses and cold fronts meet in a region where mountains favor the formation of storm clouds and precipitation. This week's "DANA" phenomenon was one of the three most intense such storms recorded in the last century in the Valencia region, said Ruben del Campo, spokesman for Spain's national meteorological agency, Aemet. "The forecasts were in line with what happened. However, in an area between Utiel and Chiva, in the province of Valencia, rainfall exceeded 300 liters per square meter. In that area, storm systems were continuously forming and regenerating," he explained. While experts say it will take time to analyze all the data and determine whether this "DANA" phenomenon was caused by climate change, most agree that an increase in temperature in the Mediterranean and warmer and wetter atmospheric conditions are contributing to more frequent extreme episodes. "We cannot say anything right away, except that, in the context of climate change, such events will be more frequent and intense," said Spanish meteorologist and researcher Ernesto Rodriguez-Camino. Before the term "DANA" was coined in the early 2000s, any heavy rain during autumn, a characteristic of the Mediterranean climate, was popularly known as "gota fria" (cold drop) in Spain and some regions of France. The term is still widely used colloquially. Its origin dates back to 1886, when German scientists introduced the idea of "kaltlufttropfen" (cold air drop) to describe a disturbance at high altitude, but without apparent manifestation at the surface. Aemet considers this concept of "cold drop" to be outdated and defines "DANA" as a closed depression at high altitude, which has become isolated and separated from an associated jet stream.