On the extraordinary winter flood episode over the North Atlantic Basin in 1936

• Published in: Annals of the New York Academy of Sciences
• Main Authors: Ballesteros-Cánovas, J. A., Stoffel, Markus, Benito, Gerardo, Rohrer, Mario, Barriopedro, David, García Herrera, Ricardo, Beniston, Martin, Brönnimann, Stefan
• Other Authors: Università degli studi di Genova, European Commission, Fundación Biodiversidad, Ministerio de Economía y Competitividad (España)
• Format: Article in Journal/Newspaper
• Language: English
• Published: John Wiley & Sons 2019
• Subjects: Flood; 1936; North Atlantic Basin; AO; AMO; Arctic; Pacific; North Atlantic; North Atlantic oscillation
• Online Access: http://hdl.handle.net/10261/187302; https://doi.org/10.1111/nyas.13911; https://doi.org/10.13039/501100000780; https://doi.org/10.13039/501100004702; https://doi.org/10.13039/501100003329

In this study, we analyze the linkage between atmosphere and ocean modes and winter flood variability over the 20th century based on long‐term flow‐discharge series, historical archives, and tree‐ring records of past floods in the North Atlantic Basin (NAB). The most extreme winter floods occurred in 1936 and had strong impacts on either side of the Atlantic. We hypothesize that the joint effects of sea surface temperatures (SSTs) over the Atlantic and Pacific Oceans and the Arctic Oscillation (AO), which is closely related to the North Atlantic Oscillation, play a significant role when describing flood variability in North America and Europe since 1900. Statistical modeling supports the assumption that the response of flood anomalies over the NAB to AO phases is subsidiary of SST phases. Besides, we shed light on the extraordinarily winter flood of 1936 that was characterized by very high SSTs over both the Atlantic and Pacific (>98th percentile) and very low, negative values of AO (<1st percentile). This outstanding winter flood episode was most likely characterized by stratospheric polar vortex anomalies, which can usually be linked to an increased probability of storms in western and southwestern Europe and increased snowfall events in eastern North America. By assessing the flood anomalies over the NAB as a coupled AO and SST function, one could further the understanding of such large‐scale events and presumably improve anticipation of future extreme flood occurrences. This study was funded by the Institute for Environmental Sciences (University of Geneva) without any specific grant. S.B. acknowledges support from the FP7 project ERA‐CLIM2. J.A.B.C. thanks Sebastian Guillet, Christophe Corona, and Jaime Madrigal for their comments. G.B. appreciates the support of Fundación Biodiversidad (MITECO) through research project DAM‐ADAPT. D.B. and R.G.‐H. were supported by the Spanish Ministry of Economy and Competitiveness through the PALEOSTRAT (CGL2015‐69699‐R) project and the European Project ...