Intertwined relationships between past interglacial climates and northern ice sheets

• Main Author: Bauch, Henning A.
• Format: Conference Object
• Language: unknown
• Published: 2012
• Subjects: Arctic; Greenland; Antarc*; Antarctica; Ice Sheet; Labrador Sea; Nordic Seas; North Atlantic; Northwest Atlantic; Sea ice
• Online Access: https://oceanrep.geomar.de/id/eprint/20674/

PP11E-04 Because of their climatic prominence elsewhere (e.g. Antarctica), interglacial periods are globally regarded as times of extreme climate warmth, paired with high sea-level and small ice sheets, for instance on Greenland. It has been suggested that the Greenland ice sheet (GIS) was considerably smaller during past interglaciations. Although no complete record of an interglacial cycle exists from Greenland, marine records from the Labrador Sea also imply a largely reduced southern GIS for MIS5e and 11. This finding seems consistent with surface ocean reconstructions from the North Atlantic where SSTs were higher in these older interglaciations than during the Holocene. These data also suggest a more vigorous subpolar gyre system with consequences for the atmospheric circulation and the ocean heat transfer into the Northwest Atlantic. By comparison, past interglaciations in the Nordic seas show cold surface conditions, especially for MIS9 and MIS11, implying a rather ’active’ eastern GIS. This contrast in the meridional ocean heat flux between the polar and subpolar North Atlantic during past interglaciations should have affected not only the actual interglacial size and melting history of the GIS. It is further concluded that the dynamical interactions between surface ocean temperature/salinity, sea ice, and atmospheric circulation patterns played the dominant role for the interglacial climate regionality in the high-latitude North Atlantic sector and, beyond that, also impacted the cross-arctic interglacial development.