Impacts of 1.5 and 2.0 °C Warming on Pan-Arctic River Discharge Into the Hudson Bay Complex Through 2070

• Published in: Geophysical Research Letters
• Main Authors: MacDonald, Matthew, Stadnyk, Tricia, Déry, Stephen J., Braun, Marco, Gustafsson, David, Isberg, Kristina, Arheimer, Berit
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union 2020
• Subjects: Hudson Bay Complex; global warming; discharge; climate change; Arctic; Canada; Foxe Basin; Hudson; Hudson Bay; Hudson Strait; Ungava Bay; Climate change; Global warming
• Online Access: http://hdl.handle.net/1993/34874; https://doi.org/10.1029/2018GL079147

Discharge projections into the Hudson Bay Complex to 2070 are investigated for global mean temperature warming levels of 1.5 and 2.0 °C. Median precipitation increases from 1986–2005, ranging from 2% during summer to 19% during winter, are projected to increase discharge in all seasons except summer. The rise in discharge is greatest furthest north, into Foxe Basin, Ungava Bay, and Hudson Strait, exceeding 10% above historical annual means. A 2.0 °C warming results in higher discharge than 1.5 °C warming owing to greater precipitation (e.g., 6.5% greater spring discharge increase); however, summer discharge for 2.0 °C warming is lower due to enhanced evaporation and lower precipitation increase from historical (4.0% lower summer discharge increase). Extreme daily high flows are projected to be greater than historical, more so for 2.0 °C warming than 1.5 °C warming, and this is greatest in the eastern and northern regions. These projections suggest continued increasing river discharge into pan-Arctic coastal oceans. Manitoba Hydro and the Natural Sciences and Engineering Research Council of Canada through the BaySys project