Flooding is a common consequence of a DANA. | Archive

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DANA, standing for isolated depression at high altitude, is commonly referred to as the cold drop ('gota fría'). A phenomenon associated with the western Mediterranean, it was a DANA that produced the torrential and devastating rains in Valencia.

Mallorca knows about the DANA all too well, but the torrential rains that affect the island, especially in the autumn, would be heavier if it wasn't for what one meteorologist refers to as a "safety valve".

Agustín Jansà is the former delegate in the Balearics of the Aemet met agency. He explains that there is a factor that tends to counteract the generation of intense rain - the wind. In this regard he points to the influence of one of the eight winds of the Mediterranean, the north wind, known in Mallorca as the Tramuntana. A warming of the sea can contribute to particularly intense rain. "But strong, cold and dry winds, such as the Tramuntana, cool surface water and therefore make it difficult for torrential rain to form.

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"After the summer, if there are repeated episodes of cold wind, the sea temperature drops gradually and effectively, so the probability of torrential rain tends to decrease. It could be said that strong, cold and dry winds are a safety valve against the risk of torrential rain, although not in all areas equally."

An area to which it does apply lies between the French coast and the Balearics. However, Jansà warns that there is a potential problem. "Climate change may be causing a decrease in the Tramuntana, which could weaken this safety valve.

"Climate change is forcing a warming of the Mediterranean, not only in summer and autumn but also in spring and even in winter. Climate change can therefore contribute to triggering torrential rains in the Mediterranean, and these rains may tend to increase in frequency and intensity."