Effect of increasing Arctic river runoff on the Atlantic meridional overturning circulation： a model study

• Published in: Acta oceanologica Sinica Vol. 36; no. 8; pp. 59 - 65
• Main Authors: Shu, Qi, Qiao, Fangli, Song, Zhenya, Xiao, Bin
• Format: Journal Article
• Language: English
• Published: Beijing The Chinese Society of Oceanography 01.08.2017; Springer Nature B.V; Key Laboratory of Marine Science and Numerical Modeling, State Oceanic Administration, Qingdao 266061, China; Laboratory for Regional Oceanography and Numerical Modeling, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; The First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China
• Subjects: Atlantic Meridional Overturning Circulation (AMOC); Circulation; Climate models; Climatology; Deep water; Earth and Environmental Science; Earth Sciences; Ecology; Engineering Fluid Dynamics; Environmental Chemistry; Freshwater; Ice; Inland water environment; Intercomparison; Marine & Freshwater Sciences; Numerical experiments; Ocean circulation; Oceanography; Projection; River discharge; River flow; River runoff; Rivers; Runoff; Seawater; 北大西洋; 北极; 数值实验; 河流径流量; 环流; 翻转; 耦合模型; 耦合模式; Arctic Ocean; Arctic; Arctic region; Arctic river runoff; Atlantic meridional overturning circulation; climate change
• ISSN: 0253-505X; 1869-1099
• DOI: 10.1007/s13131-017-1009-z

An increasing amount of freshwater has been observed to enter the Arctic Ocean from the six largest Eurasian rivers over the past several decades. The increasing trend is projected to continue in the twenty-first century according to Coupled Model Intercomparison Project Phase 5 （CMIP5） coupled models. The present study found that water flux from rivers to the Arctic Ocean at the end of the century will be 1.4 times that in 1950 according to CMIP5 projection results under Representative Concentration Pathway 8.5. The effect of increasing Arctic river runoff on the Atlantic meridional overturning circulation （AMOC） was investigated using an ocean-ice coupled model. Results obtained from two numerical experiments show that 100, 150 and 200 years after the start of an increase in the Arctic river runoff at a rate of 0.22%/a, the AMOC will weaken by 0.6 （3%）, 1.2 （7%） and 1.8 （11%） Sv. AMOC weakening is mainly caused by freshwater transported from increasing Arctic river runoff inhibiting the formation of North Atlantic Deep Water （NADW）. As the AMOC weakens, the deep seawater age will become older throughout the Atlantic Basin owing to the increasing of Arctic runoff.