%0 Journal Article
%A García-Burgos, Marina
%A Gómara Cardalliaguet, Íñigo
%A Rodríguez De Fonseca, María Belén
%A González Alemán, Juan Jesús
%A Zurita Gotor, Pablo
%A Ayarzagüena Porras, Blanca
%T Abrupt and persistent atmospheric circulation changes in the North Atlantic under La Niña conditions
%D 2023
%U https://hdl.handle.net/20.500.14352/97688
%X Several recent studies have linked the exceptional North Atlantic and Eurasian atmospheric evolution during late February and March 2018 to the Sudden Stratospheric Warming (SSW) that took place a few weeks earlier. February 2018 was characterized by an abrupt transition from the positive to the negative phase of the North Atlantic Oscillation (NAO) and a subsequent persistence of the negative NAO for several weeks. This paper investigates the contribution of atmospheric and oceanic phenomena to both the 2018 event and a set of 19 identified analogues (including the former) for the period 1959-2022. Evidence is given that La Nin similar to a conditions in the tropical Pacific and upstream North Atlantic cyclones play an important role as a trigger for these events. Ensuing two-way tropospheric-strato-spheric coupling and eddy feedbacks provide extended-range persistence for negative NAO conditions. These results may help improve the prediction of such exceptional events.
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