Evaluation Of The Results Of CFC-11 Distribution In The Oceans Simulated By Different Types Of Experiments In The GFDL Model

This article used 11 modes(GFDL-ESM2 G,GFDL-ESM2 M,GFDL-CM3 in CMIP5;CESM2,CESM2-FV2,CESM2-WACCM,CESM2-WACCM-FV2,GFDL-CM4,GFDL-ESM4,Nor ESM2-LM,Nor ESM2-MM in CMIP6)simulation results of CFC-11 in the ocean,the sea surface concentration distribution of CFC-11,the total amount of water column per unit area,the global total mass,the maximum penetration depth and,the characteristics of the vertical section of the Pacific Ocean and the Southern Ocean were analyzed.The study selected four tests in the GFDL-ESM2 G,GFDL-ESM2 M,and GFDL-CM3 models of CMIP5 to represent the average level of the GFDL model simulated tracers of the early CMIP5,combined with salinity,sea temperature data,and 8 different models of CMIP6.As a result,an analysis and comparison was made and the following conclusions were obtained:(1)The concentration gradient of CFC-11 simulated in GFDL mode is opposite to the temperature gradient.There is a clear negative correlation between them,and the correlation coefficient is-0.98.The high-value centers of the CFC-11 sea surface simulated by the GFDL model are concentrated in high latitudes,such as the North Atlantic and Northwest Pacific.(2)The total mass of CFC-11 in the global ocean simulated by GFDL is higher than the observed value,especially the simulation result of CM3 is 22.9% higher than the observation,and the average value of the GFDL model is higher than the observed 15.6%.Analysis of the zonal sections of 46 ° N in the North Pacific,24 ° N in the North Atlantic,and 65 °S in the Southern Ocean shows that the GFDL model still has some room for improvement when simulating some important water masses.For example,GFDL is too deep at the maximum value of CFC-11 concentration below 1000 m in the section of 24 ° N.Through the evaluation of the GFDL simulation CFC-11 distribution results,we can preliminary understand the reasons for the deviation of the simulated ocean ventilation,which is helpful to guide the improvement of the model.(3)The comparison between the early GFDL and CMIP6 models found that in the southern Ocean Ross Sea and Weddell Sea,the high center value(6.5 pmol/kg)of the simulation results of the eight models in CMIP6 is very close to the observation results,which is more The average level of the GFDL model is 1.5 pmol/kg higher.The problem of GFDL-CM4 and GFDL-ESM4 has been significantly improved in the GFIP-CM4 and GFDL-ESM4.The simulation results and observation results of GFDL-CM4 and GFDL-ESM4 show that the maximum position of CFC-11 concentration is around 1 500 m.Below the 1 500 m section of the 65 ° S section of the Southern Ocean,the early GFDL model simulated CFC-11 concentration results in the CMIP5 were three times higher than the observed results.The problem did not occur in the GFDL-CM4 and GFDL-ESM4 model simulation results.