Mesoscale eddies play vital roles in ocean processes.Although previous studies focused on eddy surface features and individual three-dimensional(3D)eddy cases in the northwestern Pacific Ocean,the analysis of unique e...Mesoscale eddies play vital roles in ocean processes.Although previous studies focused on eddy surface features and individual three-dimensional(3D)eddy cases in the northwestern Pacific Ocean,the analysis of unique eddy3D regional characteristics is still lacking.A 3D eddy detection scheme is applied to 9 years(2000-2008)of eddyresolving Regional Ocean Modeling System(ROMS)output to obtain a 3D eddy dataset from the surface to a depth of 1000 m in the northwestern Pacific Ocean(15°-35°N,120°-145°E).The 3D characteristics of mesoscale eddies are analyzed in two regions,namely,Box1(Subtropical Countercurrent,15°-25°N,120°-145°E)and Box2(Southern Kuroshio Extension,25°-35°N,120°-145°E).In Box1,the current is characterized by strong vertical shear and weak horizontal shear.In Box2,the current is characterized by the strong Kuroshio,topographic effect,and the westward propagation of Rossby waves.The results indicate the importance of baroclinic instability in Box1,whereas in Box2,both the barotropic and baroclinic instability are important.Moreover,the mesoscale eddies’properties in Box1 and Box2 are distinct.The eddies in Box1 have larger number and radius but a shorter lifetime.By contrast,Box2 has fewer eddies,which have smaller radius but longer lifetime.Vertically,more eddies are detected at the subsurface than at the surface in both regions;the depth of 650 m is the turning point in Box1.Above this depth,the number of cyclonic eddies(CEs)is larger than that of anticyclonic eddies(AEs).In Box2,the number of CEs is dominant vertically.Eddy kinetic energy(EKE)and mean normalized relative vorticity in Box2are significantly higher than those in Box1.With increasing depth,the attenuation trend of EKE and relative vorticity of Box1 become greater than those of Box2.Furthermore,the upper ocean(about 300 m in depth)contains 68.6%of the eddies(instantaneous eddy).Only 16.6%of the eddies extend to 1000 m.In addition,about87%of the eddies are bowl-shaped eddies in the two regions.Only about 3%are cone-shaped eddies.With increasing depth of the eddies,the proportion of bowl-shaped eddies gradually decreases.Conversely,the coneand lens-shaped eddies are equal in number at 700-1000 m,accounting for about 30%each.Studying the 3D characteristics of eddies in two different regions of the northwestern Pacific Ocean is an important stepping stone for discussing the different eddy generation mechanisms.展开更多
We report on a hexactinellid sponge new to science,Walteria demeterae sp.nov.,which was collected from the northwestern Pacific seamounts at depths of 1271–1703 m.Its tubular and basiphytous body,extensive lateral pr...We report on a hexactinellid sponge new to science,Walteria demeterae sp.nov.,which was collected from the northwestern Pacific seamounts at depths of 1271–1703 m.Its tubular and basiphytous body,extensive lateral processes,numerous oval lateral oscula which are irregularly situated in the body wall,the presence of microscleres with oxyoidal,discoidal and onychoidal outer ends,and the absence of anchorate discohexasters,indicate it belongs to the genus Walteria of family Euplectellidae,which is also supported by molecular phylogenetic evidence from 18 S,28 S,16 S rRNA and cytochrome c oxidase subunit I(COI)gene sequences.The unique morphotype,which is structured by a thin and rigid framework of body wall and lateral processes consisting of diactins,characterizes it as a new species.Local aggregations of individuals of this new species coupled with their associated macrofauna in the Suda Seamount are reported,highlighting its functional significance in providing biogenic microhabitats in the deep sea.展开更多
基金The National Natural Science Foundation of China under contract Nos NSFC 41806030 and 42076021the China Ocean Mineral Resources Research and Development Association Program under contract No.DY135-E2-3-01+4 种基金the Basic Scientific Research Business Expenses of Zhejiang Provincial Universities under contract No.2020J00007the project of State Key Laboratory of Tropical Oceanography,South China Sea Institute of Oceanology,Chinese Academy of Sciences under contract No.LTO1807the project of Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)under contract No.SML2020SP007the Innovation Group Project of Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)under contract No.311020004the Strategic Priority Research Program of Chinese Academy of Sciences under contract No.XDB42000000。
文摘Mesoscale eddies play vital roles in ocean processes.Although previous studies focused on eddy surface features and individual three-dimensional(3D)eddy cases in the northwestern Pacific Ocean,the analysis of unique eddy3D regional characteristics is still lacking.A 3D eddy detection scheme is applied to 9 years(2000-2008)of eddyresolving Regional Ocean Modeling System(ROMS)output to obtain a 3D eddy dataset from the surface to a depth of 1000 m in the northwestern Pacific Ocean(15°-35°N,120°-145°E).The 3D characteristics of mesoscale eddies are analyzed in two regions,namely,Box1(Subtropical Countercurrent,15°-25°N,120°-145°E)and Box2(Southern Kuroshio Extension,25°-35°N,120°-145°E).In Box1,the current is characterized by strong vertical shear and weak horizontal shear.In Box2,the current is characterized by the strong Kuroshio,topographic effect,and the westward propagation of Rossby waves.The results indicate the importance of baroclinic instability in Box1,whereas in Box2,both the barotropic and baroclinic instability are important.Moreover,the mesoscale eddies’properties in Box1 and Box2 are distinct.The eddies in Box1 have larger number and radius but a shorter lifetime.By contrast,Box2 has fewer eddies,which have smaller radius but longer lifetime.Vertically,more eddies are detected at the subsurface than at the surface in both regions;the depth of 650 m is the turning point in Box1.Above this depth,the number of cyclonic eddies(CEs)is larger than that of anticyclonic eddies(AEs).In Box2,the number of CEs is dominant vertically.Eddy kinetic energy(EKE)and mean normalized relative vorticity in Box2are significantly higher than those in Box1.With increasing depth,the attenuation trend of EKE and relative vorticity of Box1 become greater than those of Box2.Furthermore,the upper ocean(about 300 m in depth)contains 68.6%of the eddies(instantaneous eddy).Only 16.6%of the eddies extend to 1000 m.In addition,about87%of the eddies are bowl-shaped eddies in the two regions.Only about 3%are cone-shaped eddies.With increasing depth of the eddies,the proportion of bowl-shaped eddies gradually decreases.Conversely,the coneand lens-shaped eddies are equal in number at 700-1000 m,accounting for about 30%each.Studying the 3D characteristics of eddies in two different regions of the northwestern Pacific Ocean is an important stepping stone for discussing the different eddy generation mechanisms.
基金The National Natural Science Foundation of China under contract No.41706149the Foundation of China Ocean Mineral Resources R&D Association under contract Nos DY135-E2-2-03 and DY135-E2-2-06the Scientific Research Fund of the Second Institute of Oceanography,Ministry of Natural Resources,under contract No.JG1716
文摘We report on a hexactinellid sponge new to science,Walteria demeterae sp.nov.,which was collected from the northwestern Pacific seamounts at depths of 1271–1703 m.Its tubular and basiphytous body,extensive lateral processes,numerous oval lateral oscula which are irregularly situated in the body wall,the presence of microscleres with oxyoidal,discoidal and onychoidal outer ends,and the absence of anchorate discohexasters,indicate it belongs to the genus Walteria of family Euplectellidae,which is also supported by molecular phylogenetic evidence from 18 S,28 S,16 S rRNA and cytochrome c oxidase subunit I(COI)gene sequences.The unique morphotype,which is structured by a thin and rigid framework of body wall and lateral processes consisting of diactins,characterizes it as a new species.Local aggregations of individuals of this new species coupled with their associated macrofauna in the Suda Seamount are reported,highlighting its functional significance in providing biogenic microhabitats in the deep sea.