NARR-based analysis of changes in the mesoscale wind and temperature over the Hudson Bay Lowlands and their impact on the surface energy balance: 1979–2018

• Published in: Polar Science
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2022
• Subjects: Hudson Bay Lowlands; Climate change; Energy balance; Sea-ice; NARR; Hudson Bay; Canada; Hudson; Polar Science; Sea ice
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=16968; http://id.nii.ac.jp/1291/00016837/

The Hudson Bay exerts a strong advective influence on the surface energy balance of the adjacent Hudson Bay Lowlands (HBL) of Canada. The onshore winds are relatively cold and moist compared to the warmer and drier offshore winds. The contrasting thermal and humidity properties of these two air masses affect the partitioning of net radiation between the various heat fluxes over the HBL. We show that global warming has been accompanied by significant changes in the mesoscale wind regimes and the advective role of the Hudson Bay on the surface energy balance over the HBL. On average, we found a significant increasing trend in onshore wind frequency during the growing season of about 7% over the past 40 years. The most pronounced increase in onshore winds of 17% occurred in June during which ice cover on Hudson Bay has remained highly persistent over the past 40 years. The resulting shift from offshore to onshore winds dominance over the region has resulted in an enhancement of convective heat transfer to the atmosphere and a reduction of conductive heat transfer into the ground.