Regional high-resolution Downscaling of Climate Change in the Antarctic (REDOCCA)

Applicants

Professor Dr. Günther Heinemann
Universität Trier
Fachbereich VI - Raum- und Umweltwissenschaften
Fach Umweltmeteorologie


Dr. Tido Semmler
Alfred-Wegener-Institut
Helmholtz-Zentrum für Polar- und Meeresforschung


Dr. Ralph Timmermann
Alfred-Wegener-Institut
Helmholtz-Zentrum für Polar- und Meeresforschung

Project Description 

Changes in the Antarctic climate system are strongly related to atmosphere-ocean-sea ice inter-actions. The Weddell Sea in the Antarctic represents a key area, where AOI processes such as sea ice production in coastal polynyas and associated formation of high-salinity shelf water strongly influence ocean and cryosphere. The overall goal of the project is to study changes of the atmospheric conditions and their impact on the ocean circulation in the Weddell Sea for the mid and end of the 21st century by means of high-resolution atmosphere/ocean/sea ice modelling. A dynamical downscaling of global CMIP6 simulations will be performed using the regional climate model CCLM for the atmosphere (with 15km resolution for the Antarctic and 2km resolution for the region of the Larsen-C ice shelf), and simulations of the high-resolution sea-ice/ocean model FESOM (down to 3km resolution). In comparison with coarse-scale CMIP6 simulations for the recent climate and the future climate for the mid and end of the 21st century it will be studied how mesoscale processes of the atmospheric forcing will impact ocean circulations and how they change in the future. The sea ice production in polynyas and associated dense water formation are key processes for the southern Weddell Sea. Polynyas are a main driver of the ocean circulation beneath the Filchner-Ronne Ice Shelf, which is stabilized by this circulation in the present climate. A special focus lies also on topographic effects in the region of the Larsen-C ice shelf at the Antarctic Peninsula, which can influence melting at the surface of the ice shelf as well as the ocean circulation and basal melting beneath the ice shelf. Since global climate models cannot resolve effects on the scale of polynyas and topographic effects in the region of the Antarctic Peninsula, the project will yield an important contribution to a better understanding of changes in the frame of climate change in the Antarctic.

DFG Programme: Infrastructure Priority Programmes

term since 2019