A prior observational study indicated an asymmetric link between sea surface temperature(SST)in the Tasman Sea and ENSO during austral summer.Specifically,El Niño is associated with a dipolar SST anomaly pattern,...A prior observational study indicated an asymmetric link between sea surface temperature(SST)in the Tasman Sea and ENSO during austral summer.Specifically,El Niño is associated with a dipolar SST anomaly pattern,featuring warming in the northwest and cooling in the southeast,whereas La Niña corresponds to basin-scale warming.This study employs the experiments of coupled models from the sixth phase of the Coupled Model Intercomparison Project(CMIP6)to assess ENSO’s impact on Tasman Sea SST.While all 15 models capture the observed dipolar SST anomalies(SSTAs)in the Tasman Sea during El Niño years,only 7 models capture the basin-scale warmth in the Tasman Sea during La Niña years.Consequently,the models are bifurcated into two groups:group-one models yield one physically reasonable asymmetric connection as observed,including the asymmetry of oceanic heat transport,especially the Ekman meridional transport anomalies induced by zonal wind stress driven by the asymmetric atmospheric circulation over the Tasman Sea.However,due to abnormal responses to ENSO and systematic biases in model simulations,including jet and storm tracks,oceanic heat fluxes,ocean currents,and SST,the group-two models fail to reproduce the asymmetric connection between the Tasman Sea and ENSO.This study not only validates the observational asymmetric connection of SSTAs in the Tasman Sea with respect to the two opposite ENSO phases,but also provides evidence and clues to reduce the bias in group-two models.展开更多
The winter temperature variability of the Antarctic Peninsula(AP)has been proven to be influenced by sea surface temperature(SST)anomalies over the Tasman Sea.Using outputs over an extended time period from historical...The winter temperature variability of the Antarctic Peninsula(AP)has been proven to be influenced by sea surface temperature(SST)anomalies over the Tasman Sea.Using outputs over an extended time period from historical experiments,the skills of CMIP6 models in simulating the atmospheric responses to Tasman Sea SST are evaluated in this study,with an emphasis on the relationships with AP temperatures.The spatial correlation coefficient and normalized standard deviation are used as the evaluation metrics.Corresponding results suggest that the majority of CMIP6 models can capture the basic spatial distributions of Tasman Sea-related teleconnections across the Southern Hemisphere extratropical region,featuring a Pacific–South America-like pattern.However,the overestimation of atmospheric interannual variability and the underestimation of oceanic interannual variability in CMIP6 models result in a considerable amplification of the atmospheric responses to SST anomalies.The model uncertainty in depicting the relationships between Tasman Sea SSTs and AP surface temperatures,as well as the associated teleconnections,can partially be attributed to variations in grid resolutions among models.Additionally,further analysis of the Antarctic sea ice shows that the Tasman Sea SST may contribute to the interannual variability of the Antarctic dipole in CMIP6.展开更多
This study uses linear regression and composite analyses to identify a pronounced asymmetric connection of sea surface temperature(SST)in the Tasman Sea with the two opposite phases of El Ni?o-Southern Oscillation(ENS...This study uses linear regression and composite analyses to identify a pronounced asymmetric connection of sea surface temperature(SST)in the Tasman Sea with the two opposite phases of El Ni?o-Southern Oscillation(ENSO)during austral summer.In El Ni?o years,the SST anomalies(SSTAs)in the Tasman Sea exhibit a dipolar pattern with weak warmth in the northwest and modest cooling in the southeast,while during La Ni?a years the SSTAs exhibit a basin-scale warmth with greater amplitude.Investigations into the underlying mechanism suggest that this asymmetry arises from a mechanism related to oceanic heat transport,specifically the anomalous Ekman meridional heat transport induced by the zonal wind stress anomalies,rather than the surface heat fluxes on the air-sea interface.Further analysis reveals that the asymmetry of oceanic heat transport between El Ni?o and La Ni?a years is driven by the asymmetric atmospheric circulation over the Tasman Sea stimulated by the asymmetric diabatic heating in the tropical Pacific between the two opposite ENSO phases.展开更多
Southern Hemisphere mid-latitude westerlies contribute to the ventilation of the deep Southern Ocean(SO),and drive changes in atmospheric carbon dioxide(CO2) and the global climate.As the westerlies control directly o...Southern Hemisphere mid-latitude westerlies contribute to the ventilation of the deep Southern Ocean(SO),and drive changes in atmospheric carbon dioxide(CO2) and the global climate.As the westerlies control directly oceanic fronts,the movement of the subtropical front(STF) reflects the westerlies migration.Thus it is important to understand the relationships between STF movement and the weaterlies,ventilation of the deep SO,ice volume and atmospheric CO2.To this end,we use two new high-resolution records from early Marine Isotope Stage(MIS) 20(～800 ka) of sea surface temperature(SST) based on U k' 37 paleo-thermometer and benthic oxygen isotope(δ 18OB) at Ocean Drilling Program(ODP) Site 1170B in the southern Tasman Sea(STS),to construct linkages between the marine records and atmospheric proxies from Antarctic ice-cores.During the last 800 ka,the average SST(10.2℃) at Site 1170B is 1.8℃ lower than today(annual average 12℃).The highest average SST of 11.6℃ occurred during MIS 1,and the lowest average SST of 7.8℃ occurred during MIS 2.The warmest and coldest records of 14.7℃ and 6.2℃ occurred in the MIS 5 and MIS 2,respectively.In the glacial-interglacial cycles of the last 800 ka,variability of reconstructed SST shows that the STF moved northward or southward more than 3° of latitude compared with its present location.In the warmest stage MIS 5,the STF shifted to its southernmost location of ～49°S.In contrast,in the coldest stage MIS 2,the STF moved to its northernmost location of ～43°S.In response to orbital cycles,the westerlies movement led ice volume and atmospheric CO2 changes,but it was in phase with change in Antarctic atmospheric temperature.Ice volume only preceded atmospheric CO2 only a little at the 23-ka precession band,lagged the atmospheric CO2 at the 100-ka eccentricity band,and was in phase with atmospheric CO2 at the 40-ka obliquity band.展开更多
塔斯曼海位于西南太平洋地区,处于印度-澳大利亚板块和西兰板块之间,大地构造背景复杂。该地区是全球油气资源勘探的重点海域之一,但是国内对该地区的研究相当匮乏。本文根据塔斯曼海海域的自由空气重力异常对塔斯曼海海域的构造单元进...塔斯曼海位于西南太平洋地区,处于印度-澳大利亚板块和西兰板块之间,大地构造背景复杂。该地区是全球油气资源勘探的重点海域之一,但是国内对该地区的研究相当匮乏。本文根据塔斯曼海海域的自由空气重力异常对塔斯曼海海域的构造单元进行了划分,前人关于塔斯曼海的研究主要集中在Resolution海岭北部,我们认为塔斯曼海的范围应包括Resolution海岭以南,麦夸里海岭以西,塔斯曼断裂带以东的区域(即南部次盆)。结果显示,塔斯曼海域及邻区包括3个一级构造单元:东澳大利亚陆缘、西兰板块和塔斯曼海盆,且塔斯曼海盆可进一步划分为西部次盆、东部次盆和南部次盆。本文基于塔斯曼海域90 Ma以来的洋壳年龄数据编制了构造演化图,将塔斯曼海的形成演化过程分为4个阶段:(1)中生代陆内裂谷期(90～83 Ma BP);(2)塔斯曼海扩张阶段(83～61 Ma BP);(3)塔斯曼海北部扩张停止阶段(61～52 Ma BP);(4)塔斯曼海南部改造阶段(52 Ma BP至今)。展开更多
The Early–mid Cretaceous marks the confluence of three major continental-scale events in eastern Gondwana:(1)the emplacement of a Silicic Large Igneous Province(LIP)near the continental margin;(2)the volcaniclastic f...The Early–mid Cretaceous marks the confluence of three major continental-scale events in eastern Gondwana:(1)the emplacement of a Silicic Large Igneous Province(LIP)near the continental margin;(2)the volcaniclastic fill,transgression and regression of a major epicontinental seaway developed over at least a quarter of the Australian continent;and(3)epeirogenic uplift,exhumation and continental rupturing culminating in the opening of the Tasman Basin c.84 Ma.The Whitsunday Silicic LIP event had widespread impact,producing both substantial extrusive volumes of dominantly silicic pyroclastic material and coeval first-cycle volcanogenic sediment that accumulated within many eastern Australian sedimentary basins,and principally in the Great Australian Basin system(>2 Mkm^(3)combined volume).The final pulse of volcanism and volcanogenic sedimentation at c.105–95 Ma coincided with epicontinental seaway regression,which shows a lack of correspondence with the global sea-level curve,and alternatively records a wider,continental-scale effect of volcanism and rift tectonism.Widespread igneous underplating related to this LIP event is evident from high paleogeothermal gradients and regional hydrothermal fluid flow detectable in the shallow crust and over a broad region.Enhanced CO_(2)fluxing through sedimentary basins also records indirectly,large-scale,LIP-related mafic underplating.展开更多
The northern extremity of the late Neoproterozoic-Paleozoic Tasman Orogenic zone exposed in north Queensland forms a narrow belt of tectonised rock assemblages abutting Paleoproterozoic–Mesoproterozoic rocks of the N...The northern extremity of the late Neoproterozoic-Paleozoic Tasman Orogenic zone exposed in north Queensland forms a narrow belt of tectonised rock assemblages abutting Paleoproterozoic–Mesoproterozoic rocks of the North Australian craton.The craton-orogen contact(Tasman Line)is extensively exposed,a unique circumstance for Australia.Sedimentary protoliths of the cratonic rocks were mainly deposited between 1700–1600 Ma and multiply deformed between 1600–1500 Ma.The Lynd Mylonite Zone,one expression of the Tasman Line,separates rocks of the late Neoproterozoic–Ordovician Thomson Orogen from those of the craton.The succeeding Silurian–Devonian Mossman Orogen is generally faulted against the Thomson Orogen,but in its northern extent it may directly abut the craton along the Palmerville Fault,also an expression of the Tasman Line.These two orogenic systems are dominantly of active margin association and E-stepping but deep seismic imaging indicates that they are extensively underlain by crust of Archean or Paleoproterozoic age.The Tasman Orogenic Zone in its southern part represents a broad tract of crust c.1,000 km across,added to the cratonic core of Australia in a phase of rapid accretion.In contrast,for its north Queensland development a much smaller volume of new crust was generated,expressing slow accretion.For this region the orogenic system laps extensively onto cratonic crust,a geometry which at least in part reflects overthusting during episodes of Paleozoic contractional orogenesis.As a consequence of little orogenic accretionary outgrowth of the north Queensland continental margin,three large-scale,successive igneous assemblages of active margin association generated throughout the Paleozoic form largely co-located and overprinting belts with plutonic suites stitching the Tasman Line and extending into the craton.展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2023YFF0805101)the National Natural Science Founda-tion of China(Grant Nos.42376250 and 42405068).
文摘A prior observational study indicated an asymmetric link between sea surface temperature(SST)in the Tasman Sea and ENSO during austral summer.Specifically,El Niño is associated with a dipolar SST anomaly pattern,featuring warming in the northwest and cooling in the southeast,whereas La Niña corresponds to basin-scale warming.This study employs the experiments of coupled models from the sixth phase of the Coupled Model Intercomparison Project(CMIP6)to assess ENSO’s impact on Tasman Sea SST.While all 15 models capture the observed dipolar SST anomalies(SSTAs)in the Tasman Sea during El Niño years,only 7 models capture the basin-scale warmth in the Tasman Sea during La Niña years.Consequently,the models are bifurcated into two groups:group-one models yield one physically reasonable asymmetric connection as observed,including the asymmetry of oceanic heat transport,especially the Ekman meridional transport anomalies induced by zonal wind stress driven by the asymmetric atmospheric circulation over the Tasman Sea.However,due to abnormal responses to ENSO and systematic biases in model simulations,including jet and storm tracks,oceanic heat fluxes,ocean currents,and SST,the group-two models fail to reproduce the asymmetric connection between the Tasman Sea and ENSO.This study not only validates the observational asymmetric connection of SSTAs in the Tasman Sea with respect to the two opposite ENSO phases,but also provides evidence and clues to reduce the bias in group-two models.
基金jointly supported by the National Natural Science Foundation of China(Grant No.42375027)the Natural Science Foundation of Guangdong Province(Grant No.2023A1515010889)。
文摘The winter temperature variability of the Antarctic Peninsula(AP)has been proven to be influenced by sea surface temperature(SST)anomalies over the Tasman Sea.Using outputs over an extended time period from historical experiments,the skills of CMIP6 models in simulating the atmospheric responses to Tasman Sea SST are evaluated in this study,with an emphasis on the relationships with AP temperatures.The spatial correlation coefficient and normalized standard deviation are used as the evaluation metrics.Corresponding results suggest that the majority of CMIP6 models can capture the basic spatial distributions of Tasman Sea-related teleconnections across the Southern Hemisphere extratropical region,featuring a Pacific–South America-like pattern.However,the overestimation of atmospheric interannual variability and the underestimation of oceanic interannual variability in CMIP6 models result in a considerable amplification of the atmospheric responses to SST anomalies.The model uncertainty in depicting the relationships between Tasman Sea SSTs and AP surface temperatures,as well as the associated teleconnections,can partially be attributed to variations in grid resolutions among models.Additionally,further analysis of the Antarctic sea ice shows that the Tasman Sea SST may contribute to the interannual variability of the Antarctic dipole in CMIP6.
基金jointly supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA19070402)the National Natural Science Foundation of China(Grant Nos.41790473 and 41731177)。
文摘This study uses linear regression and composite analyses to identify a pronounced asymmetric connection of sea surface temperature(SST)in the Tasman Sea with the two opposite phases of El Ni?o-Southern Oscillation(ENSO)during austral summer.In El Ni?o years,the SST anomalies(SSTAs)in the Tasman Sea exhibit a dipolar pattern with weak warmth in the northwest and modest cooling in the southeast,while during La Ni?a years the SSTAs exhibit a basin-scale warmth with greater amplitude.Investigations into the underlying mechanism suggest that this asymmetry arises from a mechanism related to oceanic heat transport,specifically the anomalous Ekman meridional heat transport induced by the zonal wind stress anomalies,rather than the surface heat fluxes on the air-sea interface.Further analysis reveals that the asymmetry of oceanic heat transport between El Ni?o and La Ni?a years is driven by the asymmetric atmospheric circulation over the Tasman Sea stimulated by the asymmetric diabatic heating in the tropical Pacific between the two opposite ENSO phases.
基金supported by the National Natural Science Foundation of China (40321603 and 40676030)the National Basic Research Program of China (2007CB815903)the Chinese IPY Program (2007–2009)
文摘Southern Hemisphere mid-latitude westerlies contribute to the ventilation of the deep Southern Ocean(SO),and drive changes in atmospheric carbon dioxide(CO2) and the global climate.As the westerlies control directly oceanic fronts,the movement of the subtropical front(STF) reflects the westerlies migration.Thus it is important to understand the relationships between STF movement and the weaterlies,ventilation of the deep SO,ice volume and atmospheric CO2.To this end,we use two new high-resolution records from early Marine Isotope Stage(MIS) 20(～800 ka) of sea surface temperature(SST) based on U k' 37 paleo-thermometer and benthic oxygen isotope(δ 18OB) at Ocean Drilling Program(ODP) Site 1170B in the southern Tasman Sea(STS),to construct linkages between the marine records and atmospheric proxies from Antarctic ice-cores.During the last 800 ka,the average SST(10.2℃) at Site 1170B is 1.8℃ lower than today(annual average 12℃).The highest average SST of 11.6℃ occurred during MIS 1,and the lowest average SST of 7.8℃ occurred during MIS 2.The warmest and coldest records of 14.7℃ and 6.2℃ occurred in the MIS 5 and MIS 2,respectively.In the glacial-interglacial cycles of the last 800 ka,variability of reconstructed SST shows that the STF moved northward or southward more than 3° of latitude compared with its present location.In the warmest stage MIS 5,the STF shifted to its southernmost location of ～49°S.In contrast,in the coldest stage MIS 2,the STF moved to its northernmost location of ～43°S.In response to orbital cycles,the westerlies movement led ice volume and atmospheric CO2 changes,but it was in phase with change in Antarctic atmospheric temperature.Ice volume only preceded atmospheric CO2 only a little at the 23-ka precession band,lagged the atmospheric CO2 at the 100-ka eccentricity band,and was in phase with atmospheric CO2 at the 40-ka obliquity band.
文摘塔斯曼海位于西南太平洋地区,处于印度-澳大利亚板块和西兰板块之间,大地构造背景复杂。该地区是全球油气资源勘探的重点海域之一,但是国内对该地区的研究相当匮乏。本文根据塔斯曼海海域的自由空气重力异常对塔斯曼海海域的构造单元进行了划分,前人关于塔斯曼海的研究主要集中在Resolution海岭北部,我们认为塔斯曼海的范围应包括Resolution海岭以南,麦夸里海岭以西,塔斯曼断裂带以东的区域(即南部次盆)。结果显示,塔斯曼海域及邻区包括3个一级构造单元:东澳大利亚陆缘、西兰板块和塔斯曼海盆,且塔斯曼海盆可进一步划分为西部次盆、东部次盆和南部次盆。本文基于塔斯曼海域90 Ma以来的洋壳年龄数据编制了构造演化图,将塔斯曼海的形成演化过程分为4个阶段:(1)中生代陆内裂谷期(90～83 Ma BP);(2)塔斯曼海扩张阶段(83～61 Ma BP);(3)塔斯曼海北部扩张停止阶段(61～52 Ma BP);(4)塔斯曼海南部改造阶段(52 Ma BP至今)。
文摘The Early–mid Cretaceous marks the confluence of three major continental-scale events in eastern Gondwana:(1)the emplacement of a Silicic Large Igneous Province(LIP)near the continental margin;(2)the volcaniclastic fill,transgression and regression of a major epicontinental seaway developed over at least a quarter of the Australian continent;and(3)epeirogenic uplift,exhumation and continental rupturing culminating in the opening of the Tasman Basin c.84 Ma.The Whitsunday Silicic LIP event had widespread impact,producing both substantial extrusive volumes of dominantly silicic pyroclastic material and coeval first-cycle volcanogenic sediment that accumulated within many eastern Australian sedimentary basins,and principally in the Great Australian Basin system(>2 Mkm^(3)combined volume).The final pulse of volcanism and volcanogenic sedimentation at c.105–95 Ma coincided with epicontinental seaway regression,which shows a lack of correspondence with the global sea-level curve,and alternatively records a wider,continental-scale effect of volcanism and rift tectonism.Widespread igneous underplating related to this LIP event is evident from high paleogeothermal gradients and regional hydrothermal fluid flow detectable in the shallow crust and over a broad region.Enhanced CO_(2)fluxing through sedimentary basins also records indirectly,large-scale,LIP-related mafic underplating.
文摘The northern extremity of the late Neoproterozoic-Paleozoic Tasman Orogenic zone exposed in north Queensland forms a narrow belt of tectonised rock assemblages abutting Paleoproterozoic–Mesoproterozoic rocks of the North Australian craton.The craton-orogen contact(Tasman Line)is extensively exposed,a unique circumstance for Australia.Sedimentary protoliths of the cratonic rocks were mainly deposited between 1700–1600 Ma and multiply deformed between 1600–1500 Ma.The Lynd Mylonite Zone,one expression of the Tasman Line,separates rocks of the late Neoproterozoic–Ordovician Thomson Orogen from those of the craton.The succeeding Silurian–Devonian Mossman Orogen is generally faulted against the Thomson Orogen,but in its northern extent it may directly abut the craton along the Palmerville Fault,also an expression of the Tasman Line.These two orogenic systems are dominantly of active margin association and E-stepping but deep seismic imaging indicates that they are extensively underlain by crust of Archean or Paleoproterozoic age.The Tasman Orogenic Zone in its southern part represents a broad tract of crust c.1,000 km across,added to the cratonic core of Australia in a phase of rapid accretion.In contrast,for its north Queensland development a much smaller volume of new crust was generated,expressing slow accretion.For this region the orogenic system laps extensively onto cratonic crust,a geometry which at least in part reflects overthusting during episodes of Paleozoic contractional orogenesis.As a consequence of little orogenic accretionary outgrowth of the north Queensland continental margin,three large-scale,successive igneous assemblages of active margin association generated throughout the Paleozoic form largely co-located and overprinting belts with plutonic suites stitching the Tasman Line and extending into the craton.
