The investigation of internal solitary waves over a continental shelf-slope

Internal solitary waves(ISWs)always happen in marginal seas,where stable stratification exists.ISWs may carry large energy when they propagate and affect marine engineering constructions such as marine drilling platforms.Previous studies,including a large number of mooring observations and laboratory experiments,show the speed of ISWs will change when they pass by shelf slopes.Korteweg-de Vries(KdV)theory explain this phenomenon.In the paper,we use a laboratory experiment and a numerical model experiment to verify this theory.In the laboratory experiment,we injected two layers of water of different densities in a tank to simulate marine stratification and make ISWs.We use a CCD camera to record the whole process.The camera can take 16 photos per second.In the numerical experiment,we input the same original conditions as the laboratory one.The results of 18 different original conditions show the dimensionless factorδplays a key role in deciding the amplitudes and shapes of ISWs.The main conclusion also contains that small-amplitude waves match well with KdV theory while mKdV is better for largeamplitude waves.Whether the laboratory experiment or numerical experiment shows results with a high agreement.In future studies,we may use a numerical model with higher resolution to get analysis about phase speed and energy of ISWs.

The influence of the initial temperature field on sea ice simulations in the Bohai Sea in winter of 2015/2016

To assess the influence of the initial temperature field on ocean temperature and sea ice simulations,a climatological dataset(WOA18),a real-time varying dataset(SODA),and an analysis field obtained after applying the“vertical projection”assimilation scheme were selected to obtain the initial temperature field(the initial moment was December 1,2015)for use in the sea ice simulation of the HAMSOM ice-ocean coupled model,considering the Bohai Sea in the 2015/2016 winter.In this study,after using this assimilation scheme,the analysis initial temperature field showed significant improvement.The simulated SST results showed that the initial temperature field had a considerable effect on the SST results in the first 45 days of the model run;after this period,the effect became negligible and the model internal dynamics and atmospheric forcing became dominant.The simulated sea ice results showed that the ice area and ice edge distance(i.e.,the distance between the intersection of the central axis and the ice edge line and axis apex)results obtained in experiment E3 which used the analysis initial temperature field were improved by~14%and~35%,respectively,and those obtained in experiment E2 which used the real-time varying initial temperature field were improved by~10%and~22%,respectively,compared to the results of experiment E1 which used the climatological initial temperature field.