Coexistence of nitrous oxide undersaturation and oversaturation in the surface and subsurface of the

• 作 者: JiexiaZhang[1]LiyangZhan[2]LiqiChen[1]YuhongLi[2]JianfangChen[3]
• 机 构: Key Laboratory of Global Change and Marine-Atmospheric Chemistry of State Oceanic Administration,Thi
• 出 处: 2015中国极地科学学术年会
• 发表日期: 2015年期

　　The nitrous oxide(N2O)distributions in a shelf–slope–basin section from the Chukchi Sea shelf to the Chukchi Abyssal Plain(CAP)in the western Arctic Ocean were observed for the first time during the 4th Chinese National Arctic Research Expedition(4th CHINARE)in late August 2010.The N2O concentrations were 11.4 – 16.7 nmol L-1,with saturation values of 91 – 118%in the surface water.In the surface,biological N2O production was negligible,and physical processes dominate the surface N2O saturation.The undersaturation may be the result of dilution by sea ice meltwater.The oversaturation may be caused by the diffusing of N2O-rich shelf bottom water.Below the surface,N2O concentrations ranged from 11.4 to 21.4 nmol L-1.In the vertical direction,variations in the N2O concentration on the Chukchi Sea shelf may be related to sediment denitrification and water-column N2O production by nitrification.The subsurface maxima in the UHL may receive partial contributions from nitrification production but are primarily caused by the spreading of shelf water,which can transport water with elevated N2O levels into the basin.