TY - JOUR
T1 - Projected changes to wintertime air-sea turbulent heat fluxes over the subpolar North Atlantic Ocean
AU - Barrell, Christopher
AU - Renfrew, Ian A.
AU - King, John C.
AU - Abel, Steven J.
AU - Elvidge, Andrew D.
N1 - Acknowledgments: This study was part of the Iceland Greenland Seas Project, supported by the Natural Environmental Research Council (NERC) AFIS Grant (NE/N009754/1). This work was also supported by NERC via the EnvEast DTP (Grant NE/L002582/1). The authors acknowledge the UK Met Office Hadley Centre modelling group and others who contributed to the HadGEM3-GC3.1 climate model, supported by NERC. Model data was accessed from the Centre for Environmental Data Analysis (CEDA) using the JASMIN supercomputing service (https://www.jasmin.ac.uk). The authors also acknowledge the European Centre for Medium-Range Weather Forecasts (ECMWF) for providing the ERA5 reanalysis data set. We'd like to thank the reviewers for comments that have improved the final paper.
PY - 2023/4
Y1 - 2023/4
N2 - In wintertime over the subpolar North Atlantic Ocean (SPNA), the strongest surface sensible and latent heat fluxes typically occur just downstream of the sea-ice edge. The recent retreat in Arctic wintertime sea ice is changing the distribution of these turbulent heat fluxes, with consequences for the formation of the dense waters that feed into the Atlantic Meridional Overturning Circulation. Projections of turbulent heat flux over the SPNA are investigated using output from the HadGEM3-GC3.1 climate model, produced as part of the sixth phase of the Coupled Model Inter-Comparison Project. Comparison of two model resolutions (MM: 60 km atmosphere—1/4° ocean and HH: 25 km–1/12°) shows that the HH configuration more accurately simulates historic sea ice and turbulent heat flux distributions. The MM configuration tends to produce too much sea ice in the SPNA, affecting the turbulent heat flux distribution; however, it displays improved performance during winters with less sea ice, increasing confidence in future projections when less sea ice is predicted. Future projections are presented for low (SSP1-2.6) and high (SSP5-8.5) emissions pathways. The simulations agree in predicting that, with climate change, the SPNA will see reductions in wintertime sea ice and air-sea turbulent fluxes later in the 21st century, particularly in the Labrador and Irminger Seas and the interior of the Nordic Seas, and a notable reduction in their decadal variability. These effects are more severe under the SSP5-8.5 pathway. The implications for SPNA ocean circulation are discussed.
AB - In wintertime over the subpolar North Atlantic Ocean (SPNA), the strongest surface sensible and latent heat fluxes typically occur just downstream of the sea-ice edge. The recent retreat in Arctic wintertime sea ice is changing the distribution of these turbulent heat fluxes, with consequences for the formation of the dense waters that feed into the Atlantic Meridional Overturning Circulation. Projections of turbulent heat flux over the SPNA are investigated using output from the HadGEM3-GC3.1 climate model, produced as part of the sixth phase of the Coupled Model Inter-Comparison Project. Comparison of two model resolutions (MM: 60 km atmosphere—1/4° ocean and HH: 25 km–1/12°) shows that the HH configuration more accurately simulates historic sea ice and turbulent heat flux distributions. The MM configuration tends to produce too much sea ice in the SPNA, affecting the turbulent heat flux distribution; however, it displays improved performance during winters with less sea ice, increasing confidence in future projections when less sea ice is predicted. Future projections are presented for low (SSP1-2.6) and high (SSP5-8.5) emissions pathways. The simulations agree in predicting that, with climate change, the SPNA will see reductions in wintertime sea ice and air-sea turbulent fluxes later in the 21st century, particularly in the Labrador and Irminger Seas and the interior of the Nordic Seas, and a notable reduction in their decadal variability. These effects are more severe under the SSP5-8.5 pathway. The implications for SPNA ocean circulation are discussed.
U2 - 10.1029/2022EF003337
DO - 10.1029/2022EF003337
M3 - Article
VL - 11
JO - Earths Future
JF - Earths Future
SN - 2328-4277
IS - 4
M1 - e2022EF003337
ER -