RCP4.5情景下预测21世纪南海海平面变化

结合卫星高度计资料和SODA温盐数据,本文利用CCSM(Community Climate System Model version4)气候系统模式在代表性浓度路径RCP4.5情景下对全球海平面变化趋势的预测模拟结果作为强迫场,用POP模式模拟预测21世纪南海海平面长期趋势变化及空间分布。模拟结果显示,在RCP4.5情景下,南海海域在21世纪末10年平均海平面相对于20世纪末10年上升了15~39cm,明显上升海域位于中南半岛东部的南海中部、南部海域和吕宋海峡东西两侧海域,上升值最大可达39cm。如果加上格陵兰和南极等陆地冰川融化的影响,21世纪南海总海平面上升值将可能达到35~75cm。南海比容海平面明显上升区域位于吕宋岛东面的深水海域,广东沿岸流和吕宋冷涡之间海域,以及中南半岛东南部海域。总比容海平面的变化主要来自热比容,盐比容贡献比较小。南海南部和西部比容海平面上升速率较低,如加里曼丹岛西北侧、泰国湾和海南岛西侧有下降趋势。

Sea level variations in the South China Sea during the 21st century under RCP4.5

Combining the Satellite altimeter data and SODA temperature-salinity data,in this paper we have simulated the long-term trends and the spatial distribution of the sea level of South China Sea (SCS) during the 21st century with the POP model. The forcing field of the POP model is the predicted global simulation results of CCSM4 (Community Climate System Model version4) model under the Representative Concentration Pathways Scenarios (RCP4.5). The simulated results show that the average sea level in the last ten years of 21st century of the South China Sea would rise by 15 to 39 cm compared to that in the last ten years of 20th century. The significant sea level increase would locate in areas such as the eastern and southeastern of Indo-China Peninsula,and the east and west sides of Luzon Strait. The maximum rise could reach up to 39 cm. If the influence of the melting glaciers such as Greenland sheet and Antarctica sheet was considered,the total rise of the south China sea level during the 21st century could reach 35 to 75 cm. The significant increase of the steric sea level would locate in areas such as the deep-water basin in the east of Luson Island,the waters between the Guangdong Coastal Current and Luzon Cold Eddy and the southeastern of Indo-China Peninsula. The total steric sea level change mainly came from thermal steric sea level,while the contribution of halo steric was small. The steric sea level rise rate was relatively low in the southern and western of South China Sea,e.g. a downward trend was shown on the northwest of Kalimantan Island,in the gulf of Thailand and on the west of Hainan Island.