A Study Of The Changing Snow Density Scenario And The Interannual Variation Of Negative Salinity Anomalies In The Canadian Basin

Snow on the sea ice has an important impact on the mass balance and energy balance of the Arctic Ocean.Accurate snow depth simulation is vital for numerical models.When comparing the spatial distribution and average value of snow depth from different model outputs with satellite measurements,it's difficult to investigate the impacts of variable snow density on the simulation of snow depth in the Arctic Ocean.Considering meteorological factors such as air temperature and wind speed,an empirical snow density model is employed to design sensitivity study: Case A,snow density model considering all meteorological factors.Case B,constant snow density.Case C,same as A but the influence of wind speed on the densification is not considered.Case D,same as A but the influence of temperature on the densification is not considered.These simulated results are validated by the ground truth of one of the SNOTEL observation sites.The results concluded from the following aspects with the period of 2018/11-2019/05: 1)the mean snow density and depth simulated in Case A are both close to the results in Case B,with lower root mean square error(RMSE)of the simulated snow depth than Case B.2)the Case A are capabale to reproduce the high frequency variations of snow depth on the time scale from days to ten days,and reduce the relative errors,which were related with each other,3)combining the results of Case C and D,the influence of temperature on snow densification is much smaller than that of wind speed.,which simulation is an essential factor of temperature and salinity anomalies in the Canadian BasinNot only does the simulation of snow depth help to improve the numerical model's simulation accuracy,but the change in snow depth also has an impact on the salinity in the ocean.The melted snow moved into the ocean and the surface snow transport caused by wind blowing snow,increasing freshwater storage and lowering salinity in the ocean,which are vital factors for the salinity anomaly in the Canadian Basin.In the study of the interannual variability of the strong low salinity anomaly in the Canadian Basin from 2003 to 2014,it is illustrated that: 1)the Regional Arctic System Model(RASM)model has reproduced the interannual variability of strong negative anomaly in the surface layer(0-20 m)salinity of the Canadian Basin from2006 to 2012,2)the interannual variability has a greater impact on the positive surface temperature anomaly in the Canadian Basin from August to October,2006 to 2012 than the long-term warming trend from 2003 to 2014,3)the long-term variation trends of surface salinity and temperature in the Canadian Basin from August to October,2003 to 2014 were-0.092 PSU/yr and 0.074°C/yr,respectively.4)The surface salinity of the Canadian Basin is significantly negatively correlated with temperature,with the negative anomaly in the surface layer much stronger than that in the subsurface layer.Under the spatial and temporal continuity of the RASM model outputs,biochemical variables such as nitrate,Net Primary Productivity(NPP),and chlorophyll in the surface layer of the Canadian Basin were further analyzed that they varied in the different regions overall.