Response of the Arctic sea ice–ocean system to meltwater perturbations based on a one-dimensional model study

Abstract

A one-dimensional coupled sea ice–ocean model is used to investigate how the Arctic Ocean stratification and sea ice respond to changes in meltwater. In the control experiments, the model is capable of accurately simulating seasonal changes in the upper-ocean stratification structure compared with observations, and the results suggest that ocean stratification is important for ice thickness development during the freezing 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 reduced ice melting by 17 % by strengthening ocean stratification. (3) The impact of meltwater released during the previous melting season on ice growth in winter depends on the strength of stratification. After removing all the meltwater during the summer, ice formation in areas with strong stratification increased by 12 % during the winter, while it decreased by 43 % in areas with weak stratification. (4) In some areas of the Nansen Basin where stratification is nearly absent, the warm Atlantic Water can reach the ice directly 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.