Turbulent mixing in the upper ocean（30-200 m） of the northwestern Weddell Sea is investigated based on profiles of temperature,salinity and microstructure data obtained during February 2014.Vertical thermohaline str...Turbulent mixing in the upper ocean（30-200 m） of the northwestern Weddell Sea is investigated based on profiles of temperature,salinity and microstructure data obtained during February 2014.Vertical thermohaline structures are distinct due to geographic features and sea ice distribution,resulting in that turbulent dissipation rates（ε） and turbulent diffusivity（K） are vertically and spatially non-uniform.On the shelf north of Antarctic Peninsula and Philip Ridge,with a relatively homogeneous vertical structure of temperature and salinity through the entire water column in the upper 200 m,both ε and K show significantly enhanced values in the order of O（10^（-7））-O（10^（-6）） W/kg and O（10^（-3））-O（10^（-2）） m^2/s respectively,about two or three orders of magnitude higher than those in the open ocean.Mixing intensities tend to be mild due to strong stratification in the Powell Basin and South Orkney Plateau,where s decreases with depth from O（10^（-8）） to O（10^（-9）） W/kg,while K changes vertically in an inverse direction relative to s from O（10^（-6）） to O（10^（-5）） m^2/s.In the marginal ice zone,K is vertically stable with the order of10^（-4） m^2/s although both intense dissipation and strong stratification occur at depth of 50-100 m below a cold freshened mixed layer.Though previous studies indentify wind work and tides as the primary energy sources for turbulent mixing in coastal regions,our results indicate weak relationship between K and wind stress or tidal kinetic energy.Instead,intensified mixing occurs with large bottom roughness,demonstrating that only when internal waves generated by wind and tide impinge on steep topography can the energy dissipate to support mixing.In addition,geostrophic current flowing out of the Weddell Sea through the gap west of Philip Passage is another energy source contributing to the local intense mixing.展开更多
海洋和大气是地球气候系统关键组成部分,其相互作用对全球气候及人类生活产生深远影响。为了分析海气相互作用的研究现状与未来的发展趋势。采用文献计量分析方法,运用VOSviewer和CiteSpace工具,筛选了中国知网(China National Knowledg...海洋和大气是地球气候系统关键组成部分,其相互作用对全球气候及人类生活产生深远影响。为了分析海气相互作用的研究现状与未来的发展趋势。采用文献计量分析方法,运用VOSviewer和CiteSpace工具,筛选了中国知网(China National Knowledge Infrastructure,CNKI)和Web of Science核心合集数据库中关于海气相互作用的文献,通过分析关键词共现网络图谱、时间序列图谱、突现网络图谱以及文献的发文国家和机构分布,对1981-2021年中国在该领域的研究进展和未来发展趋势进行了综合评估。同时,本研究还选取了2001-2021年的国际文献,对全球范围内的研究进展和热点问题进行了分析。研究表明,国内外在海气相互作用领域的研究均从宏观到微观角度深入探讨,着重研究了大气和海洋的基本作用机理,并进一步分析了影响地球气候系统的多种因素,目前研究重点转向了极端天气系统的预测及其运行机制。从研究机构和国家分布来看,高校与政府机构是主要的研究主体,国内研究机构之间的合作联系较为紧密。研究关键方向和方法,从宏观层面的基础研究转向更为深入的海气通量和大尺度过程研究。这一转变反映了国际海洋发展战略的调整,同时为未来的研究方向提供了新的视角和思路。展开更多
基金Chinese Polar Environment Comprehensive Investigation and Assessment Programs under contract Nos CHINARE-01-01and CHINARE-04-01
文摘Turbulent mixing in the upper ocean（30-200 m） of the northwestern Weddell Sea is investigated based on profiles of temperature,salinity and microstructure data obtained during February 2014.Vertical thermohaline structures are distinct due to geographic features and sea ice distribution,resulting in that turbulent dissipation rates（ε） and turbulent diffusivity（K） are vertically and spatially non-uniform.On the shelf north of Antarctic Peninsula and Philip Ridge,with a relatively homogeneous vertical structure of temperature and salinity through the entire water column in the upper 200 m,both ε and K show significantly enhanced values in the order of O（10^（-7））-O（10^（-6）） W/kg and O（10^（-3））-O（10^（-2）） m^2/s respectively,about two or three orders of magnitude higher than those in the open ocean.Mixing intensities tend to be mild due to strong stratification in the Powell Basin and South Orkney Plateau,where s decreases with depth from O（10^（-8）） to O（10^（-9）） W/kg,while K changes vertically in an inverse direction relative to s from O（10^（-6）） to O（10^（-5）） m^2/s.In the marginal ice zone,K is vertically stable with the order of10^（-4） m^2/s although both intense dissipation and strong stratification occur at depth of 50-100 m below a cold freshened mixed layer.Though previous studies indentify wind work and tides as the primary energy sources for turbulent mixing in coastal regions,our results indicate weak relationship between K and wind stress or tidal kinetic energy.Instead,intensified mixing occurs with large bottom roughness,demonstrating that only when internal waves generated by wind and tide impinge on steep topography can the energy dissipate to support mixing.In addition,geostrophic current flowing out of the Weddell Sea through the gap west of Philip Passage is another energy source contributing to the local intense mixing.
文摘海洋和大气是地球气候系统关键组成部分,其相互作用对全球气候及人类生活产生深远影响。为了分析海气相互作用的研究现状与未来的发展趋势。采用文献计量分析方法,运用VOSviewer和CiteSpace工具,筛选了中国知网(China National Knowledge Infrastructure,CNKI)和Web of Science核心合集数据库中关于海气相互作用的文献,通过分析关键词共现网络图谱、时间序列图谱、突现网络图谱以及文献的发文国家和机构分布,对1981-2021年中国在该领域的研究进展和未来发展趋势进行了综合评估。同时,本研究还选取了2001-2021年的国际文献,对全球范围内的研究进展和热点问题进行了分析。研究表明,国内外在海气相互作用领域的研究均从宏观到微观角度深入探讨,着重研究了大气和海洋的基本作用机理,并进一步分析了影响地球气候系统的多种因素,目前研究重点转向了极端天气系统的预测及其运行机制。从研究机构和国家分布来看,高校与政府机构是主要的研究主体,国内研究机构之间的合作联系较为紧密。研究关键方向和方法,从宏观层面的基础研究转向更为深入的海气通量和大尺度过程研究。这一转变反映了国际海洋发展战略的调整,同时为未来的研究方向提供了新的视角和思路。
