Arctic open-water periods are projected to lengthen dramatically by 2100 Abstract journal article ['eddc5af7-8854-4204-ac03-d1f1b4c6d6d7', '5b2d8203-4b89-4b28-9701-eb31bdfb2e95'] 1.0 Springer Nature 2021 10.1038/s43247-021-00183-x Crawford, Alex Personal alex.crawford@umanitoba.ca Centre for Earth Observation Science - University of Manitoba 0000-0003-1561-290X ORCID http://orcid.org/ Stroeve, Julienne Personal juliene.stroeve@umanitoba.ca Centre for Earth Observation Science - University of Manitoba 0000-0001-7316-8320 ORCID http://orcid.org/ Smith, Abigail Personal Jahn, Alexandra Personal Creative Commons Attribution 4.0 International Open CC-BY-4.0 SPDX https://spdx.org/licenses Online Resource dataset related_to Arctic Sea Ice Phenology in CMIP6 https://canwin-datahub.ad.umanitoba.ca/data/dataset/sea-ice-cmip6 Arctic Climatic models climate change sea ice Arctic open-water periods are projected to lengthen dramatically by 2100 The shrinking of Arctic-wide September sea ice extent is often cited as an indicator of modern climate change; however, the timing of seasonal sea ice retreat/advance and the length of the open-water period are often more relevant to stakeholders working at regional and local scales. Here we highlight changes in regional open-water periods at multiple warming thresholds. We show that, in the latest generation of models from the Coupled Model Intercomparison Project (CMIP6), the open-water period lengthens by 63 days on average with 2 °C of global warming above the 1850-1900 average, and by over 90 days in several Arctic seas. Nearly the entire Arctic, including the Transpolar Sea Route, has at least 3 months of open water per year with 3.5 °C warming, and at least 6 months with 5 °C warming. Model bias compared to satellite data suggests that even such dramatic projections may be conservative. In several of the Arctic ocean basins, the period of open water without sea-ice cover will lengthen by more than 90 days under 2 oC of global warming, suggest analyses of the latest (CMIP6) climate model simulations. PDF application/pdf 4044809.0