Glacial-interglacial 3D ice sheet modelling of Antarctica; Validation by age-isotope advection

Abstract:

Constraining and validating large scale ice sheet modeling with respect to the proxy horizon of the last 800 kyrs is limited to sparse model data intercomparison of e.g. grounding line positions, ice sheet elevation and deep ice core records. We employ a state of the art 3D ice sheet model (ISM) (RIMBAY Thoma et.al. 2014, Göller et. al. 2013, Pattyn 2003) equipped with a tracer advection module to simulate the evolution of the Antarctic ice sheet over the last glacial cycles. The ice sheet is forced by surface climatology derived from observations (present day) and GCM climate models (ECHAM time slices LGM, Eemian), 3D ocean temperature and proxy derived global sea level data. The range of potential ice sheet response, is investigated by applying different forcing scenarios and “wiggling” the ISM’s parameters space. Modelling the age-isotope distribution at selected deep ice core sites, and subsequent comparison to the ice cores’ age-depth relation supports the interpretation of our simulations.