Variability in the ICES/NAFO region between 1950 and 2009: observations from the ICES Report on Ocean Climate

• Published in: ICES Journal of Marine Science
• Main Authors: Hughes, Sarah L., Holliday, N. Penny, Gaillard, Fabienne, Working Group On Oceanic Hydrography, Ices
• Other Authors: Marine Laboratory, Marine Scotland Science, National Oceanography Centre Southampton (NOC), University of Southampton, Laboratoire de physique des océans (LPO), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2012
• Subjects: circulation; multidecadal variability; North Atlantic; salinity; temperature; [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography; Nordic Seas; North Atlantic oscillation
• Online Access: https://hal.science/hal-00716282; https://doi.org/10.1093/icesjms/fss044

International audience The ICES Report on Ocean Climate presents the latest information on the status and trends of sea temperature and salinity in the North Atlantic and Nordic Seas. It is the main product of the ICES Working Group on Oceanic Hydrography, published annually. Bringing together multiple time-series from across the ICES and NAFO regions offers insight into the concurrent spatial and temporal trends in ocean temperature and salinity. This paper presents an overview of the physical variability in the North Atlantic Ocean at decadal and longer time-scales and reviews the current state of understanding of the causes and mechanisms of this variability. Between the 1960s and the 1990s, the North Atlantic Oscillation (NAO) index increased from a persistent negative phase in the 1960s to a strong positive phase during the 1980s and early 1990s. However, during the decade 2000-2009, because of shifts in atmospheric pressure patterns, the NAO was weak and the NAO index was not a good indicator of atmospheric forcing. Marked changes were also observed in oceanographic indices such as the Subpolar Gyre index during the mid-1990s and, as a consequence, conditions in the decade 2000-2009 have been very different from those of the previous four decades.