Freshwater generated by ice melting is an important factor in maintaining the stratification of the upper oceans, which may also have an impact on sea ice melt and growth, but it is still unclear how the Arctic Ocean and sea ice respond to the melt water. In this study, numerical experiments based on a one-dimensional coupled sea ice-ocean model were conducted to investigate the effects of melt water on the upper ocean stratification and sea ice growth/melt in different regions of the Arctic Ocean by removing the melt water from the model. The control runs simulate the stratification of the Arctic Ocean reasonably well, capturing important features such as the fresh surface layer, the salty cold halocline, and the Near-Surface Temperature Maximum and show that ocean stratification is important for ice growth, with less sea ice formation in areas with weak stratification. Decreasing melt water is found to weaken the stratification and to produce a saltier and deeper mixed layer. An important consequence is that the existing melt water has negative feedback to ice melting for all stations, and it is negative feedback to ice formation in areas with strong stratification but positive feedback in areas with weak stratification. Most importantly, in some areas of the Nansen Basin where the halocline is not fully developed, the warm Atlantic water can directly reach the ice in early spring when removing all the melt water from the model, causing early melting of sea ice in winter. A general outcome of the study is that, depending on ocean stratification, the ice cover of the Arctic Ocean can be divided into one part with weak melt water feedback (the major part) and another part with strong melt water feedback (mainly in the Nansen Basin).