RT Journal Article T1 New observational insights into the atmospheric circulationover the Euro‑Atlantic sector since 1685 A1 Mellado Cano, Javier A1 Barriopedro Cepero, David A1 García Herrera, Ricardo A1 Trigo, Ricardo M. AB Wind direction kept in ships’ logbooks is a consolidated but underexploited observational source of relevant climatic information. In this paper, we present four indices of the monthly frequency of wind direction, one for each cardinal direction: Northerly (NI), Easterly (EI), Southerly (SI) and Westerly (WI), based on daily wind direction observations taken aboard ships over the English Channel. These Directional Indices (DIs) are the longest observational record of atmospheric circulation to date at the daily scale, covering the 1685–2014 period. DIs anomalies are associated with near-surface climatic signals over large areas of Europe in all seasons, with zonal indices (WI and EI) and meridional indices (NI and SI) often afecting different regions. Statistical models including all DIs are able to explain a considerable amount of European climate variability, in most cases higher than that accounted for by the North Atlantic Oscillation. As such, the DIs are able to reproduce the known European climatic history and provide new insights of certain episodes from monthly to multi-decadal time scales such as the warm winter decade of 1730–1739 or the extremely cold 1902 summer. The DIs show the potential to better constrain the atmospheric circulation response to external forcings and its associated anomalies. In particular, we provide frst observational evidences of all year-round atmospheric circulation signals following the strongest tropical volcanic eruptions of the last three centuries. These signatures are more complex than previously thought and suggest that the well-reported winter warming and summer cooling cannot be simply interpreted in terms of changes in zonality. PB Springer SN 0930-7575 YR 2020 FD 2020-01 LK https://hdl.handle.net/20.500.14352/6054 UL https://hdl.handle.net/20.500.14352/6054 LA eng NO © The Author(s) 2019. This work is a contribution to UID/ GEO/50019/2013-Instituto Dom Luiz. Javier Mellado-Cano was supported by the Portuguese Science Foundation (FCT) through the PhD fellowship PD/BD/106028/2014, and by the Spanish Ministry of Economy and Competitiveness through the PALEOSTRAT (CGL2015- 69699-R) project through the contract PAII18/19/2/2019/14. Ricardo M. Trigo was funded through the Portuguese Science Foundation (FCT) HOLMODRIVE (PTDC/CTA-GEO/29029/2018) project. The authors are particularly thankful to the NOAA for providing the ICOADS 3.0 dataset (http://icoads.noaa.gov/). Temperature data and precipitation were provided by the CRU (http://www.cru.uea.ac.uk) and the GPCC (http://gpcc.dwd.de), respectively. Support for the Twentieth Century Reanalysis Project version 2c dataset is provided by the U.S. Department of Energy, Ofce of Science Biological and Environmental Research (BER), and by the National Oceanic and Atmospheric Administration Climate Program Ofce. The authors are grateful to D. Wheeler and M.C Álvarez-Castro for their help on the abstraction of wind direction data from the Royal Navy ships’ logbooks. The authors are grateful to Ryan Neely III for providing an updated version of the VolcanEESM database since 1685. We thank two anonymous reviewers for their useful comments that helped to improve the original manuscript. NO Ministerio de Economía y Competitividad (MINECO) NO Portuguese Science Foundation (FCT) NO Instituto Dom Luiz NO U.S. Department of Energy, Ofce of Science Biological and Environmental Research (BER) NO National Oceanic and Atmospheric Administration Climate Program Ofce DS Docta Complutense RD 29 abr 2024