A numerical study on meltwater feedback in the coupled Arctic Sea ice-ocean system

• Main Authors: Zhang, Haohao, Bai, Xuezhi, Wang, Kaiwen
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2023
• Subjects: article; Verlagsveröffentlichung; Arctic; Nansen Basin; Sea ice
• Online Access: https://doi.org/10.5194/egusphere-2023-477; https://noa.gwlb.de/receive/cop_mods_00065538; https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00064058/egusphere-2023-477.pdf; https://egusphere.copernicus.org/preprints/2023/egusphere-2023-477/egusphere-2023-477.pdf

A one-dimensional, coupled sea ice-ocean model is used to investigate the effects of meltwater on upper ocean stratification and sea ice melt and growth by decreasing the release of meltwater to the ocean. In the control experiments, the model is capable of accurately simulating seasonal changes in the upper ocean stratification structure compared to observations, and the results suggest that ocean stratification is important for ice thickness development during the growing season. The sensitivity experiments reveal the following: 1) A decrease in meltwater release weakens ocean stratification and creates a deeper, higher salinity mixed layer. 2) Meltwater release has negative feedback on ice melting, reducing ice melting by 19 % by strengthening ocean stratification. 3) The impacts of meltwater release from the previous melting season on ice growth depend on the strength of stratification, with negative feedback (reducing ice growth by 14 %) in areas with strong stratification and positive feedback (increasing ice growth more than 40 %) in areas with weak stratification. 4) In some areas of the Nansen Basin where stratification is nearly absent, the warm Atlantic water can directly reach the ice in early spring, leading to early melting of the sea ice in winter if all meltwater is removed from the model. These findings contribute to our understanding of the complex interactions between ocean stratification, meltwater, and sea ice growth and have important implications for climate models and future change prediction in the Arctic.