Simulation And Projection Of The Sea Level Changes Using Non-Boussinesq POP Based On Global Warming

In the context of global warming,sea level change is accelerating,the average rate of global sea level change from 1993 to 2010 reached 3.2 mm/a,which is close to double the rate of increase from 1901 to 2010.However,the ocean model contained in the CMIP5 model only outputs dynamic sea level results,it is impossible to simulate sea level change caused by thermal expansion of seawater.This paper uses modified NonBoussinesq POP(Parallel Ocean Program)model to simulate the change of sea level in 1986-2013 and project the global sea-level changes from 2006 to 2100 under RCP4.5 and RCP8.5 scenarios.The main conclusions obtained are:(1)Non-Boussinesq POP has a good simulation of the sea level changes: The result of sea level change of model simulation from 1993 to 2013 is very close to the factual data.Whether the spatial distribution or the regional average,the model can simulate the sea level change well.The simulation results show that the global sea level has risen by 72.8mm,and the rate of increase has reached 2.6mm/a during the period from 1986 to 2013.(2)Compared with the CMIP5 model,the Non-Boussinesq model has a great improvement on the simulation of sea level change: Comparing the POP results with the sea surface height of CMIP5,we can find that the results of the Non-Boussinesq model are much better than the CMIP5,whether it is the regional average or the spatial distribution of sea level changes.(3)In the future,global sea level will continue to rise: Under the RCP4.5 and RCP8.5 scenarios,global sea levels will rise by 0.36 m and 0.43 m respectively in 2100,which is close to the result in IPCC5(RCP4.5:0.32-0.63 m,RCP8.5:0.45-0.82m),with large ascending regions appearing in the Kuroshio extension waters,the South Atlantic,the south-west Pacific and the Indian Ocean.