ATLAS 5th General Assembly - Atlantic Paleo Circulation: A long-term context for the modern Ocean

• Exceptionally weak industrial-era AMOC (caused by weak LSW and
ISOW).
• Has AMOC weakening continued through the 20th century? Relative
cooling of SPG may be related to horizontal gyre circulation rather than
deep components of AMOC.
• Unprecedented 20th century changes in subpolar gyre circulation caused
pronounced changes in Northeast Atlantic hydrography and ecosystems.
• Recent variability is not simply ‘typical ongoing decadal variability’. Likely
future no-analogue conditions. Reliance on climate model projections.
• Better understanding of post Little Ice Age and 20th century changes is
required for assessing climate model sensitivity and projections of AMOC.