GFDL模式不同类型试验模拟海洋中CFC-11分布结果的评估

Evaluation of CFC-11 distribution results in different experiments of GFDL model

为了评估美国地球物理流体动力学实验室(GFDL)模式模拟海洋通风的能力,利用GFDL的物理气候系统模式和地球系统模式(GFDL-ESM2G、GFDL-ESM2M、GFDL-CM3)模拟海洋中CFC-11(一氟三氯甲烷,CCl3F)的资料,对CFC-11的海面浓度分布、单位面积水柱总量、全球总物质的量、最大穿透深度以及在大西洋、太平洋、南大洋的垂直剖面的特征进行了分析。本文将GFDL模拟结果与盐度、海温、CFC-11的观测资料比较,得到了如下重要结论:GFDL模式模拟的CFC-11海面高值中心集中在高纬度,如北大西洋、西北太平洋,但是在南大洋罗斯海、威德尔海模拟结果比观测值低了1.5 pmol·kg^-1,这是CFC-11的溶解度与海面温度成负相关造成的,即随海面温度升高,CFC-11的溶解度降低;GFDL模拟的全球海洋中CFC-11总物质的量都比观测值高,尤其是CM3的模拟结果比观测高22.9%,GFDL模式平均值高于观测15.6%。通过对北太平洋46°N、北大西洋24°N和南大洋65°S的纬向断面的分析表明,目前GFDL模式在模拟一些重要水团时还有一定的改进空间,比如GFDL在24°N断面1000 m以下模拟CFC-11浓度极大值位置过深。

In order to evaluate the ability of the United States Geophysical Fluid Dynamics Laboratory(GFDL)model to simulate ocean ventilation,three GFDL models(GFDL-ESM2G,GFDL-ESM2M,GFDL-CM3)are used to simulate the data of CFC-11(CCl3F)in the ocean.The characteristics of sea surface concentration,total water column per unit area,total amount of substance,maximum penetration depth,and vertical cross section(in the Atlantic Ocean,the Pacific Ocean,and the Southern Ocean)of CFC-11 are analyzed.By comparing the simulation results of the GFDL models with the observations of salinity,sea temperature,and CFC-11,the following conclusions are obtained.The high-value centers of CFC-11 at sea surface simulated by the GFDL models are concentrated in high latitudes,such as the North Atlantic and western North Pacific.However,the simulation result in the Ross Sea and the Weddell Sea is 1.5 pmol·kg^-1 lower than the observation,which is caused by the negative correlation between the solubility of CFC-11 and sea surface temperature,that is,the solubility of CFC-11 decreases as the sea surface temperature increases.The total amount of substance of CFC-11 in the global oceans simulated by GFDL is higher than the observation,especially the simulation result of CM3 is 22.9%higher than the observation,and the average value of the GFDL models is 15.6%higher than the observation.The 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 there is still some room for the GFDL models to improve when simulating some important water masses.For example,the position of the maximum value of CFC-11 concentration simulated by the GFDL models is too deep below 1000 m in the section of 24°N.