Quantifying

The stratigraphic identification of the i2B greenhouse intervals requires a reliable  suite of dating methods. This is particularly challenging in the Arctic where several “standard methods” are  severely hampered. However, we are confident we can tackle these challenges, given the previous  success of i2B team members. We will use state-of-the-art dating techniques to establish a robust  chronostratigraphic framework (Task 1.1).

We will subsequently apply a multi-disciplinary toolbox to  reconstruct surface water masses/currents, sea surface temperature and salinity, sea ice cover/concentrations  and ice sheet variability using novel and established techniques (Task 1.2) that were insufficiently (or not at  all) applied during earlier (I)ODP legs or conventional coring expeditions to the Arctic region.

Guided by these new Arctic archives, i2B will thoroughly evaluate existing global climate and ice sheet model simulations,  focussing on extracting information relevant for i2B on Arctic atmosphere, ocean, sea ice and ice sheets (Task 1.3). New simulations using the latest versions of NorESM and AWI-ESM will be performed (Task 1.4),  following Model Intercomparison Project (MIP) protocols, while also aiming to be in the closest possible  agreement with the paleo-information.

This collection of past conditions of Arctic warmth in WP1 will  inform the process-understanding envisioned in WP2 and the impact studies of a blue Arctic in WP3.

Work package lead: Jochen Knies