In the northwestern North Pacific,annual net air-sea CO_(2) flux is greatest in the Kuroshio Extension(KE)zone,owing to its low annual mean partial pressure of CO_(2)(pCO_(2)),and it decreases southward across the bas...In the northwestern North Pacific,annual net air-sea CO_(2) flux is greatest in the Kuroshio Extension(KE)zone,owing to its low annual mean partial pressure of CO_(2)(pCO_(2)),and it decreases southward across the basin.To quantify the influences of factors controlling the latitudinal gradient in CO_(2) uptake,sea surface pCO_(2) and related parameters were investigated in late spring of 2018 in a study spanning the KE,Kuroshio Recirculation(KR),and subtropical zones.We found that the sea-to-air pCO_(2) difference(ΔpCO_(2))was negative and at its lowest in the KE zone.ΔpCO_(2) gradually increased southward across the KR zone,and the sea surface was nearly in air-equilibrium with atmospheric CO_(2) in the subtropical zone.We found that northward cooling and vertical mixing were the two major processes governing the latitudinal gradient in surface pCO_(2) and ΔpCO_(2),while biological influences were relatively minor.In the KE zone affected by upwelling,the vertical-mixing-induced increase in surface pCO_(2) likely canceled out approximately 61%of the decrease in surface pCO_(2) caused by cooling and biological activities.Moreover,the prolonged air-sea equilibration for CO_(2) and relatively short hydraulic retention time jointly led to the low surface pCO_(2) in the KE zone in spring.Ultimately,the cooling KE current flows out of the region before it can be re-equilibrated with atmospheric CO_(2).展开更多
During the recent four decades since 1980,a series of modern climate satellites were launched,allowing for the measurement and record-keeping of multiple climate parameters,especially over the polar regions where trad...During the recent four decades since 1980,a series of modern climate satellites were launched,allowing for the measurement and record-keeping of multiple climate parameters,especially over the polar regions where traditional observations are difficult to obtain.China has been actively engaging in polar expeditions.Many observations were conducted during this period,accompanied by improved Earth climate models,leading to a series of insightful understandings concerning Arctic and Antarctic climate changes.Here,we review the recent progress China has made concerning Arctic and Antarctic climate change research over the past decade.The Arctic temperature increase is much higher than the global-mean warming rate,associated with a rapid decline in sea ice,a phenomenon called the Arctic Amplification.The Antarctic climate changes showed a zonally asymmetric pattern over the past four decades,with most of the fastest changes occurring over West Antarctica and the Antarctic Peninsula.The Arctic and Antarctic climate changes were driven by anthropogenic greenhouse gas emissions and ozone loss,while tropical-polar teleconnections play important roles in driving the regional climate changes and extreme events over the polar regions.Polar climate changes may also feedback to the entire Earth climate system.The adjustment of the circulation in both the troposphere and the stratosphere contributed to the interactions between the polar climate changes and lower latitudes.Climate change has also driven rapid Arctic and Southern ocean acidification.Chinese researchers have made a series of advances in understanding these processes,as reviewed in this paper.展开更多
Oceanic uptake and storage of anthropogenic CO_(2)(CANT)are regulated by ocean circulation and ventilation.To decipher the storage and redistribution of CANT in the western North Pacific,where a major CANT sink develo...Oceanic uptake and storage of anthropogenic CO_(2)(CANT)are regulated by ocean circulation and ventilation.To decipher the storage and redistribution of CANT in the western North Pacific,where a major CANT sink develops,we investigated the water column carbonate system,dissolved inorganic radiocarbon and ancillary parameters in May and August 2018,spanning the Kuroshio Extension(KE,35-39°N),Kuroshio Recirculation(KR,27-35°N)and subtropical(21-27°N)zones.Water column CANT inventories were estimated to be 40.5±1.1 mol m^(-2) in the KR zone and 37.2±0.9 mol m^(-2) in the subtropical zone.In comparison with historical data obtained in 2005,relatively high rates of increase of the CANT inventory of 1.05±0.20 and 1.03±0.12 mol m^(-2) yr^(-1) in the recent decade were obtained in the KR and subtropical zones,respectively.Our water-mass-based analyses suggest that formation and transport of subtropical mode water dominate the deep penetration,storage,and redistribution of CANT in those two regions.In the KE zone,however,both the water column CANT inventory and the decadal CANT accumulation rate were small and uncertain owing to the dynamic hydrology,where the naturally uplifting isopycnal surfaces make CANT penetration relatively shallow.The findings of this study improve the understanding of the spatiotemporal variations of CANT distribution,storage,and transport in the western North Pacific.展开更多
We concentrate on the skin effects and topological properties in the multilayer non-Hermitian Su−Schrieffer−Heeger (SSH) structure, by taking into account the nonreciprocal couplings between the different sublattices ...We concentrate on the skin effects and topological properties in the multilayer non-Hermitian Su−Schrieffer−Heeger (SSH) structure, by taking into account the nonreciprocal couplings between the different sublattices in the unit cells. Following the detailed demonstration of the theoretical method, we find that in this system, the skin effects and topological phase transitions induced by nonreciprocal couplings display the apparent parity effect, following the increase of the layer number of this SSH structure. On the one hand, the skin effect is determined by the parity of the layer number of this SSH system, as well as the parity of the band index of the bulk states. On the other hand, for the topological edge modes, such an interesting parity effect can also be observed clearly. Next, when the parameter disorders are taken into account, the zero-energy edge modes in the odd-layer structures tend to be more robust, whereas the other edge modes are easy to be destroyed. In view of these results, it can be ascertained that the findings in this work promote to understand the influences of nonreciprocal couplings on the skin effects and topological properties in the multilayer SSH lattices.展开更多
基金The Senior User Project of R/V Kexue of the Center for Ocean Mega-Science,Chinese Academy of Sciences under contract No.KEXUE2020G07the Open Fund Project of the State Key Laboratory of Tropical Oceanography,South China Sea Institute of Oceanology,Chinese Academy of Sciences under contract No.LTO1906the Survey Project of Environmental Radioactivity Detection in the Western Pacific(R/V Xiangyanghong 3)of the Laboratory of Marine Isotopic Technology and Environmental Risk Assessment,Third Institute of Oceanography,Ministry of Natural Resource.
文摘In the northwestern North Pacific,annual net air-sea CO_(2) flux is greatest in the Kuroshio Extension(KE)zone,owing to its low annual mean partial pressure of CO_(2)(pCO_(2)),and it decreases southward across the basin.To quantify the influences of factors controlling the latitudinal gradient in CO_(2) uptake,sea surface pCO_(2) and related parameters were investigated in late spring of 2018 in a study spanning the KE,Kuroshio Recirculation(KR),and subtropical zones.We found that the sea-to-air pCO_(2) difference(ΔpCO_(2))was negative and at its lowest in the KE zone.ΔpCO_(2) gradually increased southward across the KR zone,and the sea surface was nearly in air-equilibrium with atmospheric CO_(2) in the subtropical zone.We found that northward cooling and vertical mixing were the two major processes governing the latitudinal gradient in surface pCO_(2) and ΔpCO_(2),while biological influences were relatively minor.In the KE zone affected by upwelling,the vertical-mixing-induced increase in surface pCO_(2) likely canceled out approximately 61%of the decrease in surface pCO_(2) caused by cooling and biological activities.Moreover,the prolonged air-sea equilibration for CO_(2) and relatively short hydraulic retention time jointly led to the low surface pCO_(2) in the KE zone in spring.Ultimately,the cooling KE current flows out of the region before it can be re-equilibrated with atmospheric CO_(2).
基金supported by the National Key Research and Development Program of China(2018YFA 0605703)the National Natural Science Foundation of China(No.41976193 and No.42176243)+8 种基金X.CHEN was supported by the National Key Research and Development Program of China(2019YFC1509100)the National Science Foundation of China(No.41825012)B.WU was supported by the Major Program of the National Natural Science Foundation of China(41790472)the National Key Basic Research Project of China(2019YFA0607002)the National Natural Science Foundation of China(41730959)X.CHENG was funded by the Innovation Group Project of Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(Grant No.311021008)M.DING was supported by the National Natural Science Foundation of China(42122047 and 42105036)the Basic Research Fund of the Chinese Academy of Meteorological Sciences(2021Y021 and 2021Z006)Q.SUN was supported by the National Key R&D Program of China(No.2022YFE0106300).
文摘During the recent four decades since 1980,a series of modern climate satellites were launched,allowing for the measurement and record-keeping of multiple climate parameters,especially over the polar regions where traditional observations are difficult to obtain.China has been actively engaging in polar expeditions.Many observations were conducted during this period,accompanied by improved Earth climate models,leading to a series of insightful understandings concerning Arctic and Antarctic climate changes.Here,we review the recent progress China has made concerning Arctic and Antarctic climate change research over the past decade.The Arctic temperature increase is much higher than the global-mean warming rate,associated with a rapid decline in sea ice,a phenomenon called the Arctic Amplification.The Antarctic climate changes showed a zonally asymmetric pattern over the past four decades,with most of the fastest changes occurring over West Antarctica and the Antarctic Peninsula.The Arctic and Antarctic climate changes were driven by anthropogenic greenhouse gas emissions and ozone loss,while tropical-polar teleconnections play important roles in driving the regional climate changes and extreme events over the polar regions.Polar climate changes may also feedback to the entire Earth climate system.The adjustment of the circulation in both the troposphere and the stratosphere contributed to the interactions between the polar climate changes and lower latitudes.Climate change has also driven rapid Arctic and Southern ocean acidification.Chinese researchers have made a series of advances in understanding these processes,as reviewed in this paper.
基金The research was supported by the National Natural Science Foundation of China(42141001 and 91858210).
文摘Oceanic uptake and storage of anthropogenic CO_(2)(CANT)are regulated by ocean circulation and ventilation.To decipher the storage and redistribution of CANT in the western North Pacific,where a major CANT sink develops,we investigated the water column carbonate system,dissolved inorganic radiocarbon and ancillary parameters in May and August 2018,spanning the Kuroshio Extension(KE,35-39°N),Kuroshio Recirculation(KR,27-35°N)and subtropical(21-27°N)zones.Water column CANT inventories were estimated to be 40.5±1.1 mol m^(-2) in the KR zone and 37.2±0.9 mol m^(-2) in the subtropical zone.In comparison with historical data obtained in 2005,relatively high rates of increase of the CANT inventory of 1.05±0.20 and 1.03±0.12 mol m^(-2) yr^(-1) in the recent decade were obtained in the KR and subtropical zones,respectively.Our water-mass-based analyses suggest that formation and transport of subtropical mode water dominate the deep penetration,storage,and redistribution of CANT in those two regions.In the KE zone,however,both the water column CANT inventory and the decadal CANT accumulation rate were small and uncertain owing to the dynamic hydrology,where the naturally uplifting isopycnal surfaces make CANT penetration relatively shallow.The findings of this study improve the understanding of the spatiotemporal variations of CANT distribution,storage,and transport in the western North Pacific.
基金the LiaoNing Revitalization Talents Program(Grant No.XLYC1907033)the National Natural Science Foundation of China(Grant No.11905027)+1 种基金the Natural Science Foundation of Liaoning province(Grant No.2023-MS-072)Fundamental Research Funds for the Central Universities of Ministry of Education of China(Grant Nos.N2209005 and N2205015).
文摘We concentrate on the skin effects and topological properties in the multilayer non-Hermitian Su−Schrieffer−Heeger (SSH) structure, by taking into account the nonreciprocal couplings between the different sublattices in the unit cells. Following the detailed demonstration of the theoretical method, we find that in this system, the skin effects and topological phase transitions induced by nonreciprocal couplings display the apparent parity effect, following the increase of the layer number of this SSH structure. On the one hand, the skin effect is determined by the parity of the layer number of this SSH system, as well as the parity of the band index of the bulk states. On the other hand, for the topological edge modes, such an interesting parity effect can also be observed clearly. Next, when the parameter disorders are taken into account, the zero-energy edge modes in the odd-layer structures tend to be more robust, whereas the other edge modes are easy to be destroyed. In view of these results, it can be ascertained that the findings in this work promote to understand the influences of nonreciprocal couplings on the skin effects and topological properties in the multilayer SSH lattices.
