"1. We performed a wide range of sensitivity experiments with EC-Earth3 at standard resolution to test the impact of ocean heat transport on Arctic sea ice. In these sensitivity experiments, we artificially increased the sea-surface temperature with different levels of warming in different regions of the Atlantic and Pacific oceans. This led to an increase in the ocean heat transport, and consequently to a decrease in Arctic sea-ice area and volume. We found that for a same amount of ocean heat transport increase, the reductions in Arctic sea-ice area and volume were stronger when the sea-surface temperature increase was imposed in the North Pacific, compared to the North Atlantic. The peer-reviewed paper associated with this work has been published in Climate Dynamics: ""Docquier et al. (2021). Impact of ocean heat transport on the Arctic sea-ice decline: a model study with EC-Earth3. Climate Dynamics,
https://doi.org/10.1007/s00382-020-05540-8"(s’ouvre dans une nouvelle fenêtre)". This work has also been presented at the European Geosciences Union (EGU) General Assembly 2020.
2. We performed different sensitivity experiments with the standard resolution of EC-Earth3 in which we strongly reduced the sea-ice albedo in different ways. All these experiments resulted in a strong reduction of the Arctic sea-ice area and volume, especially in the summer, when a complete disappearance occurred within the very first years. We found that due to the drastic Arctic sea-ice loss, the Atlantic ocean heat transport slightly increased north of 65°N, following the temperature rise of the northward water masses associated with sea-ice loss, and decreased south of 65°N, suggesting an impact of Arctic sea ice on the Atlantic Meridional Overturning Circulation (AMOC) in our experiments.
3. We performed model experiments with EC-Earth3 at high resolution and compared the results to the corresponding experiments performed with the standard resolution of EC-Earth3 (see point 1). We found that the relative decreases in Arctic sea-ice area and volume following the increase in ocean heat transport were relatively similar at high and standard model resolutions.
4. We investigated the present and future Arctic sea-ice area and volume and ocean heat transport in CMIP6 model simulations. We defined a series of selection criteria based on sea-ice area / volume and ocean heat transport, and we used these selection criteria to retain the CMIP6 models closest to observations over the historical period. We found that the reduction in Arctic sea-ice area and volume over the twenty-first century is stronger when applying selection criteria compared to the case without model selection (for both SSP1-2.6 and SSP5-8.5). This work is now being summarized into a peer-reviewed publication to be submitted soon: ""Docquier, D., T. Koenigk (in prep.). Refinement of future Arctic sea-ice projections"". This work has also been presented at the Bolin Days 2020 (organized by the Bolin Centre for Climate Research, Sweden).
5. Finally, a broad range of outreach activities have been performed during the project lifetime, including 2 dissemination articles written for the EGU Cryosphere Blog, a school event in Belgium, a talk with the general public at a Belgian municipality, the participation to Pint of Science Sweden, online lectures given for the students of the Stockholm University, a radio interview with RTS Switzerland, the participation to the Science is Wonderful! online exhibition, and a dissemination article written for the European Dissemination Media Agency (EDMA) Project Repository. More information can be found here:
https://sites.google.com/view/daviddocquier/outreach(s’ouvre dans une nouvelle fenêtre)".
