Seminar by Tido Semmler from Met Éireann, Dublin, Ireland
05 June 2025
KST 10:00
The Seminar is being held in Room 1010 (Jasmin) – Integrated mechanical engineering building. Click here for the campus map.
The Atlantic Meridional Overturning Circulation (AMOC) is an important part of the global ocean circulation and is responsible for a large energy transport towards the mid and high northern latitudes. It is not only important for the climate of Northwestern Europe and the east coast of North America but is globally connected. There are interactions with the Southern Ocean and the Pacific Ocean circulations that also trigger feedback mechanisms between atmosphere and ocean.
A big scientific question controversially discussed in the scientific literature is if the AMOC is on the verge of tipping or not. At Met Éireann we try to answer this question in international collaboration by refining model simulations both in terms of horizontal and vertical resolution to resolve the ocean boundary currents and in terms of more realistic representation of the land ice. A first step towards this is made by using the Alfred Wegener Institute Climate Model (AWI-CM) with 4-5 km ocean resolution over the boundary currents. The Southern Ocean is resolved at 10 km resolution. In addition, sensitivity simulations with refined Greenland meltwater input have been conducted.
AWI-CM simulations have been performed according to an extended CMIP6 HighResMIP protocol using a high emission scenario. The AMOC strength gradually declines. A shutdown of the Labrador convection occurs already during this century. At the end of this century, the AMOC strength is 40% weaker than in the 1950 control simulation – in line with the bulk of CMIP6 simulations – and settles at 5 Sv during the second half of the next century.