Based on datasets from the International Best-Track Archive for Climate Stewardship(IBTrACS)and the fifth major global reanalysis produced by ECMWF(ERA5),the authors found that 29%of tropical cyclones(TCs)in the weste...Based on datasets from the International Best-Track Archive for Climate Stewardship(IBTrACS)and the fifth major global reanalysis produced by ECMWF(ERA5),the authors found that 29%of tropical cyclones(TCs)in the western North Pacific underwent extratropical transition(ET)from 1979 to 2022,with the frequency of ET events showing a slow decreasing trend.The extratropical transition tropical cyclones(ETCs)are classified into four clusters using the k-means clustering method based on their track patterns:recurving ETCs,westward ETCs,northwestward ETCs,and abnormal track ETCs.The transition process of recurving ETCs mostly occurs after the recurvature is completed,while 63.7%of the westward ETCs complete their transition after landfall.Abnormal track ETCs undergo transition over high-latitude oceans.Northwestward ETCs have the longest duration and slowest transition speed during the ET period,resulting in a prolonged impact.The ET process occurs at the edges of the western Pacific subtropical high(WPSH),with higher frequency during westward extension and lower during eastward retreat.While westward ETCs transition through surface friction effects,others complete ET in the northwest baroclinic zone of the WPSH.展开更多
The Northwest Pacific subtropical high(NWPSH)significantly affects East Asian weather and climate,rendering the prediction of its intensity and location critically important.This study aims to evaluate the performance...The Northwest Pacific subtropical high(NWPSH)significantly affects East Asian weather and climate,rendering the prediction of its intensity and location critically important.This study aims to evaluate the performance of the Convolutional Long and Short-Term Memory(ConvLSTM)model for predicting the summertime 500 hPa geopotential height and NWPSH intensity and area at a lead time of three months,and to compare it with the dynamical models of the Nanjing University of Information Science and Technology Climate Forecast System(NUIST-CFS1.0)and the Canadian Seasonal to Interannual Prediction System Version 2(CanSIPSv2).The mean latitude-weighted RMSE(RMSE_(w)),anomaly correlation coefficient(ACC),and NWPSH indices are used as evaluation metrics.For both summer mean and monthly prediction,the ConvLSTM model outperforms the two dynamical models in terms of RMSE_(w) and ACC for the 500 hPa geopotential height over the western Pacific region.The correlation coefficients between the NWPSH intensity index predicted by the ConvLSTM model and the observations are higher than those obtained from the two dynamical models.Regarding the NWPSH area index,the ConvLSTM model shows more stable performance.Particularly in August,the improvement of the ConvLSTM model compared to the two dynamical models is more significant,indicating the robust capability in capturing late-summer circulation patterns.Therefore,the ConvLSTM model demonstrates significant potential for summer NWPSH prediction,offering a new perspective and approach for climate prediction in this region.展开更多
Based on reanalysis data and CMIP6 simulations,this study investigates the distinct responses of the cross-equatorial flows(CEFs)over the Maritime Continent(MC)under the simultaneous summer condition of two types of E...Based on reanalysis data and CMIP6 simulations,this study investigates the distinct responses of the cross-equatorial flows(CEFs)over the Maritime Continent(MC)under the simultaneous summer condition of two types of ENSO:central Pacific(CP)and eastern Pacific(EP).Results indicate that CP ENSO tends to exert stronger impacts on CEF.In CP ENSO years,significant lower-level southerly anomalies can be observed across all CEF branches adjacent to MC,accompanied by broader and deeper upper-level northerly anomalies,indicating a well-organized strengthening of both upper-and lowerlevel CEFs.In contrast,CEF anomalies in EP ENSO years tend to be weaker,with significant meridional wind anomalies confined to the east of MC.The disparities in the CEF responses can be elucidated from the perspective of convection over MC,a crucial factor in triggering CEF.In CP ENSO years,westward-leaning sea surface temperature(SST)anomalies result in a distinct cooling in MC and suppressed convection above,driving pronounced CEF anomalies.Conversely,the absence of such organized SST cooling during EP ENSO results in weaker convective forcing and subdued CEF responses.Furthermore,historical simulations from 48 CMIP6 models are utilized to validate the observational findings.Results show that model simulations can successfully reproduce the stronger impacts of CP ENSO,with a remarkable intermodel consistency.This research contributes toward a comprehensive understanding of the diversity in the relationship between CEF and ENSO types,and has implications for seasonal forecasting of CEF variability.展开更多
This paper expands Prasenjit Duara’s proposal that Asian religions and philosophies offer hope for a sustainable future.After outlining Duara’s sociology of history that describes the crisis of global modernity in t...This paper expands Prasenjit Duara’s proposal that Asian religions and philosophies offer hope for a sustainable future.After outlining Duara’s sociology of history that describes the crisis of global modernity in terms of three global changes,namely the rise of non-western nations,the crisis of climate change,and the decline of religious or transcendent sources of authority,Duara proposes that grassroots organizations coupled with Asian religious and philosophical beliefs and practices offer different ways of understanding the relationship between the person and the environment,and between our universal-planetary interests and our national interests.Drawing from Asian and Pacific indigenous teachings,I propose a type of depth ecology called“existential parity”that all things and creatures have value,generating a moral corollary called the“existential commitment”that humans take responsibility for the environment and each other.The existential commitment offers an environmental ethics that promotes sustainable agriculture to feed the world’s population.Pacific agroforestry practices can be implemented in urban settings to help mitigate climate change and food shortages.展开更多
The subantarctic mode water(SAMW)represents a large water mass in the Southern Ocean.This body of water forms through deep convection(subduction)in winter and contributes to the uptake and storage of anthropogenic hea...The subantarctic mode water(SAMW)represents a large water mass in the Southern Ocean.This body of water forms through deep convection(subduction)in winter and contributes to the uptake and storage of anthropogenic heat.However,its longterm changes in subduction rate and volume in response to shifting climate conditions are unclear.In this study,we investigated the long-term trend of the subduction rate and volume of the South Pacific–SAMW(SPSAMW)using Simple Ocean Data Assimilation outputs during 1980–2017.The results show the overall increasing trend of the subduction rate of the SPSAMW.The increased subduction of the SPSAMW directly contributes to the volume variation in the SPSAMW.The increased subduction in the South Pacific reached(0.28±0.16)Sv-1 per year,which explains nearly 68%of the volume increase in the SPSAMW.This variability in the SPSAMW reflects alterations in the overlying atmosphere.The positive to negative phase change of the Interdecadal Pacific Oscillation(IPO)in 1980–2017 deepened the Amundsen Sea Low(ASL)via atmospheric teleconnections over the South Pacific.Further analysis reveals that the increased westerly winds during the deepening of ASL resulted in more cold water transport from the south,which deepened the winter mixed layer and thus increased subduction and volume within the SPSAMW subduction region.This finding suggests the association of the long-term trends of SPSAMW subduction and volume with the phase change of the IPO.展开更多
In winter 2018,an aerosol physicochemical experiment was conducted in the Western Pacific Ocean(WPO)aboard the Research Vessel KEXUE of Chinese Academy of Sciences.This study systematically investigated both natural a...In winter 2018,an aerosol physicochemical experiment was conducted in the Western Pacific Ocean(WPO)aboard the Research Vessel KEXUE of Chinese Academy of Sciences.This study systematically investigated both natural and anthropogenic effects on marine aerosols optical properties,as well as the applicability of multi-satellite products and IMPROVE equation.The averaged aerosol optical depth(AOD500 nm)was 0.31±0.16 andÅngström exponent440–675 nm was 0.29±0.30.In offshore China,significant anthropogenic emissions affected the marine environment.In remote WPO,dust aerosols transported from northern China,Siberia,Central Asia,and those settling from the upper troposphere originating from north Africa,Arabian peninsula,and western India,were dominant.The spatial trends of AOD were opposite in the mid-latitude and southern seas of WPO.The highest AOD,0.32±0.23,appeared along the coast of South Asia at mid-latitude,decreasing from offshore seas to remote oceans.In low-latitude and equatorial seas,AOD significantly increased from coast to remote oceans.Ångström exponent dropped significantly from the coast to remote oceans as anthropogenic influence diminished across the entire WPO.Correlation analysis showed that both MODIS-C6 and Himawari AOD prod-ucts showed similar applicability in coastal urban areas,while Himawari AOD is highly recommended for coastal background and marine environment due to its finer resolution.The extinction coefficient derived from PM_(2.5) chemical compositions using IMPROVE algorithm exhibited a significant correlation(R^(2)=0.58)with the con-currently measured AOD in the absence of long-distance transport,suggesting that the IMPROVE is a reasonable proxy of the columnar average of marine aerosol extinctions free from transport influences.展开更多
How the subduction direction of the Paleo-Pacific plate beneath the Eurasian plate changes in the Early Cretaceous remains highly controversial due to the disappearance of the subducted oceanic plate.Intraplate deform...How the subduction direction of the Paleo-Pacific plate beneath the Eurasian plate changes in the Early Cretaceous remains highly controversial due to the disappearance of the subducted oceanic plate.Intraplate deformation structures in the east Asian continent,however,provide excellent opportunities for reconstructing paleostress fields in continental interior in relation to the Paleo-Pacific/Eurasian plate interaction.Anisotropy of magnetic susceptibility(AMS),geological,and geochronological analyses of post-kinematic mafic dykes intruding the detachment fault zone of the Wulian metamorphic core complex(WL MCC)in Jiaodong Peninsula exemplify emplacement of mantle-sourced dykes in a WNW-ESE(301°-121°)oriented tectonic extensional setting at ca.120 Ma.In combination with the results from our previous kinematic analysis of the MCC,a ca.21°clockwise change in the direction of intraplate extension is obtained for early(135-122 Ma)extensional exhumation of the MCC to late(122-108 Ma)emplacement of the dykes.Such a change is suggested to be related to the variation in subduction direction of the Paleo-Pacific plate beneath the Eurasian plate,from westward(pre-122 Ma)to west-northwestward(post-122 Ma).展开更多
This study investigates the distinct impacts of eastern Pacific(EP)and central Pacific(CP)El Niño events on winter shortwave solar radiation(SSR)in southern China,revealing different spatial distributions and und...This study investigates the distinct impacts of eastern Pacific(EP)and central Pacific(CP)El Niño events on winter shortwave solar radiation(SSR)in southern China,revealing different spatial distributions and underlying mechanisms.The results show that,during the developing winter of EP El Niño,significant SSR reductions occur in southwestern China and the east coast of southern China due to a strong,zonally extended Northwest Pacific anticyclone that transports moisture from the tropical Northwest Pacific and North Indian Ocean,while the northeast of southern China experiences a weak increase in SSR.In contrast,during the developing winter of CP El Niño,SSR decreases in the east of southern China with a significant decrease in the lower basin of the Yangtze River but an increase in the west of southern China with a remarkable increase in eastern Yunnan.The pronounced east-west dipole pattern in SSR anomalies is driven by a meridionally elongated Northwest Pacific anticyclone,which enhances northward moisture transport to the east of southern China while leaving western areas drier.Further research reveals that distinct moisture anomalies during the developing winter of EP and CP events result in divergent SSR distributions across southern China,primarily through modulating the total cloud cover.These findings highlight the critical need to differentiate between El Niño types when predicting medium and long-term variability of radiation in southern China.展开更多
During the boreal summer,intraseasonal oscillations exhibit significant interannual variations in intensity over two key regions:the central-western equatorial Pacific(5°S-5°N,150°E-150°W)and the s...During the boreal summer,intraseasonal oscillations exhibit significant interannual variations in intensity over two key regions:the central-western equatorial Pacific(5°S-5°N,150°E-150°W)and the subtropical Northwestern Pacific(10°-20°N,130°E-175°W).The former is well-documented and considered to be influenced by the ENSO,while the latter has received comparatively less attention and is likely influenced by the Pacific Meridional Mode(PMM),as suggested by partial correlation analysis results.To elucidate the physical processes responsible for the enhanced(weakened)intraseasonal convection over the subtropical northwestern Pacific during warm(cold)PMM years,the authors employed a moisture budget analysis.The findings reveal that during warm PMM years,there is an increase in summer-mean moisture over the subtropical northwestern Pacific.This increase interacts with intensified vertical motion perturbations in the region,leading to greater vertical moisture advection in the lower troposphere and consequently resulting in convective instability.Such a process is pivotal in amplifying intraseasonal convection anomalies.The observational findings were further verified by model experiments forced by PMM-like sea surface temperature patterns.展开更多
The duration of the extratropical transition(ET)of tropical cyclones(TCs)is often closely associated with disaster intensity.Therefore,it is essential to understand the key factors that influence ET duration.Using the...The duration of the extratropical transition(ET)of tropical cyclones(TCs)is often closely associated with disaster intensity.Therefore,it is essential to understand the key factors that influence ET duration.Using the TC best-track data and reanalysis data,this study investigates the structural characteristics and key influencing factors of ET duration in the western North Pacific(WNP)during 1981–2022.Results show that,compared to TCs that undergo ET rapidly(≤12 h),TCs that experience ET slowly(≥24 h)undergo a more prolonged and complex ET process,maintaining a warm core and an upright structure for extended periods.By contrast,TCs undergoing rapid transition experience structural disintegration within 6–12 h after ET onset.Further analysis reveals that TCs with longer ET durations are characterized by stronger warm cores,more abundant moisture,weaker environmental vertical wind shear,slower translation speeds,and a longer residence time over warmer sea surface temperatures(SSTs),all of which support the maintenance of axisymmetric structures with strong warm cores.Environmental and structural factors,including cold-air intensity,vertical wind shear,TC translation speed,SST,relative humidity,TC intensity,the radius of 17 m s^(-1)wind,mean sea level pressure,and the radius of maximum wind,are found to exist significant correlation with ET duration.Cold-air intensity exhibited the highest correlation(r=–0.35),followed by TC translation speed and SST.A relative importance analysis shows that the environmental factors play a more substantial role than the internal TC structure,accounting for about 19.23%of the variance,with TC translation speed and cold-air effects explaining 11.68%.Based on the nine factors,a statistical forecasting model was developed,which shows considerable skill in predicting ET duration.展开更多
Extratropical transition(ET)is one of the last phases of tropical cyclones(TCs)and corresponds to the structural change from a tropical system to an extratropical system characterized by pronounced asymmetric distribu...Extratropical transition(ET)is one of the last phases of tropical cyclones(TCs)and corresponds to the structural change from a tropical system to an extratropical system characterized by pronounced asymmetric distributions of heavy rainfall and strong wind.This study analyzes the statistical characteristics of ET events involving TCs over the western North Pacific(WNP)during 1981–2022.The analysis employs the Cyclone Phase Space(CPS)method to evaluate the accuracy of the fifth-generation reanalysis from the European Centre for Medium-Range Weather Forecasts(ERA5)in identifying ET based on different TC center definitions.Results show that defining the TC center by the minimum sea level pressure yields the most accurate ET identification.Subsequently,the study investigates several characteristics of ET events in the WNP.It is found that TCs undergoing ET(ETTCs)primarily form in the region of 125°–155°E,10°–25°N,with ET typically initiating between 30°–40°N and completing between 35°–50°N.These ETTCs predominantly occur from April to December,with peak activity observed from August to October.Additionally,the average duration of the ET process is 18.5 h,with longer durations observed from August to October,displaying a roughly 6-year cycle.Spatially,ET events with longer durations tend to occur at lower latitudes.Correspondingly,TCs initiating their ET phase at lower latitudes are typically stronger and larger,and they also experience longer ET durations.展开更多
The North Pacific storm track(NPST)is a high-frequency area of extratropical cyclones and an important channel for water vapor and energy transfer between low and mid–high latitudes.Previous weather and dynamic studi...The North Pacific storm track(NPST)is a high-frequency area of extratropical cyclones and an important channel for water vapor and energy transfer between low and mid–high latitudes.Previous weather and dynamic studies in this region have made significant progress,but due to the lack of ocean surface rainfall observation data,there is a lack of statistical research on precipitation in this area.In this study,statistical research on the spatiotemporal distribution characteristics of NPST rainfall was conducted based on GPM DPR(Global Precipitation Measurement Dual-frequency Precipitation Radar)observation data and ERA5 atmospheric parameters,and analysis and explanations are provided based on the atmospheric parameters.The study found that,compared to low-pressure systems,pressure gradients have a greater impact on cyclone activity and rainfall distribution.This feature,along with the meridional distribution of high atmospheric water vapor in the North Pacific Ocean and low in the north,collectively leads to the offset of high-frequency rainfall areas relative to storm tracks.The distribution of sea surface temperatures in the North Pacific Ocean affects the zonal distribution of storm tracks,causing weather disturbances and precipitation along the storm tracks to exhibit a northward extension from west to east.This study deepens our understanding of the role of NPST in global-scale water vapor and energy balance,and is of great significance for improving the prediction accuracy of climate models with respect to rainfall generated by extratropical cyclones.展开更多
The rapid intensification(RI)magnitude of tropical cyclones(TCs)over the western North Pacific(WNP)exhibits significant interannual variability and is influenced by multiple factors across various scales.These factors...The rapid intensification(RI)magnitude of tropical cyclones(TCs)over the western North Pacific(WNP)exhibits significant interannual variability and is influenced by multiple factors across various scales.These factors primarily include:interannual factors—sea surface temperature(SST)in key regions of the WNP,eastern Indian Ocean SST,El Niño-Southern Oscillation(ENSO),South Pacific Subtropical Dipole(SPSD),and western Pacific teleconnection;decadal factors—Atlantic Multidecadal Oscillation(AMO)and Pacific Decadal Oscillation(PDO);and longer-term factor—global warming.This study systematically analyzes these factors and their potential impacts,quantitatively assessing their relative importance.A statistical prediction model for the WNP TC-RI magnitude is developed based on ridge regression methods.The results indicate that the influence of these factors on the RI magnitude is closely related to the large-scale thermodynamic and dynamic conditions.Among them,the SPSD plays the most critical role in the interannual variability of the RI magnitude,followed by global warming and the AMO.Further analysis reveals that the statistical prediction model based on multiple factors demonstrates good predictive skill for the interannual variability of the TC RI magnitude.展开更多
Bomb cyclones are rapidly deepening extratropical cyclones predominantly found in midlatitude regions.These extreme events are particularly frequent over the North Pacific(NP),posing significant societal and environme...Bomb cyclones are rapidly deepening extratropical cyclones predominantly found in midlatitude regions.These extreme events are particularly frequent over the North Pacific(NP),posing significant societal and environmental risks.Currently,our understanding of the variability of bomb cyclones over the NP remains limited.This study analyzes the variations in multiple NP bomb cyclone characteristics from 1980 onward using four major reanalysis datasets.The results show a weakening trend of bomb cyclones since the beginning of the 21st century,which is characterized by significant reductions in maximum near-surface wind speeds,increases in minimum sea level pressure,and slower deepening rates.Further analysis reveals that the observed weakening trend of bomb cyclones is closely linked to a reduction in maximum 850 hPa Eady growth rate,driven primarily by reduced vertical wind shear within the 30°-45°N latitudinal band.Furthermore,our findings indicate that the Aleutian Low acts to modulate the meridional air temperature gradient over the midlatitude NP,which is corroborated by climate model outputs.This modulation provides a pathway for the Aleutian Low to affect low-level baroclinicity and thus bomb cyclone characteristics.These results have important implications for future projections of bomb cyclone activity over the NP,aiding in risk assessment and mitigating the impacts of these extreme events.展开更多
This study investigates the size characteristics and related temporal variations of tropical cyclones(TCs)over the Western North Pacific(WNP)and those affecting East China(EC)using Joint Typhoon Warning Center(JTWC)da...This study investigates the size characteristics and related temporal variations of tropical cyclones(TCs)over the Western North Pacific(WNP)and those affecting East China(EC)using Joint Typhoon Warning Center(JTWC)data during 2001-20.The average size of EC TCs is found to be similar to that over the WNP.Furthermore,the annual maximum lifetime maximum size(LMS)of EC TCs shows a statistically significant increasing trend,implying a more severe impact on the EC region.Composite analyses of intensity and size variation over the entire lifetime of TCs,before and after re-curvature,and before and after rapid intensification(RI),show that there are significant differences between them in some key areas:(1)The intensity begins to rapidly decrease after the TC has reached its highest intensity,but the size remains quasi-constant;(2)When a TC recurves south of 15°N or north of 30°N,the variation trend for both intensity and size are broadly similar before and after curvature,but their variation trends are opposite when the recurvature occurs between 15°-30°N;(3)After RI,the intensity reaches its peak value within 24 h,whereas the size reaches its LMS after30-48 h.A significant correlation is also found between the rate of change in intensity and that of size during the development stage,with a correlation coefficient of 0.67 and 0.73 for TCs in the WNP and EC,respectively.However,no significant correlation exists during the weakening stage.展开更多
Tropical cyclones(TCs)have profound impacts on socioeconomic conditions and pose substantial risks to lives and property.However,it is still unclear whether the multitimescale changes in TC activity over the past 2000...Tropical cyclones(TCs)have profound impacts on socioeconomic conditions and pose substantial risks to lives and property.However,it is still unclear whether the multitimescale changes in TC activity over the past 2000 years in the Northwestern Pacific(NWP)were regulated by Asian dust forcing.Here,we assessed the impact of Asian dust on TC activity using observational data and reconstructed records from the northern and southern NWP.Our correlation analysis of instrumental data from 1954 to 2017 reveals no significant relationship between observed TC activity and Asian dust forcing.Furthermore,we found a meridional dipole pattern of TC variation across the NWP in observations and reconstructions.These finding challenges current explanations that are based on the synchronous changes in TC activity and Asian dust forcing.Alternatively,we propose that the Western Pacific Subtropical High(WPSH)plays a crucial role in driving these meridional dipole patterns in TC variations,as supported by observations and reconstructions.The southwestward extension of an enhanced WPSH intensifies easterly flow,steering TCs westward along its southern edge.This leads to more TC activity in the southern NWP but less in the north,and vice versa when the WPSH is weakened.With the expected strengthening of the WPSH due to global warming,it is vital to consider its impact on NWP TC activity for effective risk-mitigation strategies.展开更多
During the expedition to an unnamed seamount of Caroline Ridge in the northwest Pacific Ocean,one Thalassometra specimen was sampled,and careful morphological assessment suggested that this specimen represents a new s...During the expedition to an unnamed seamount of Caroline Ridge in the northwest Pacific Ocean,one Thalassometra specimen was sampled,and careful morphological assessment suggested that this specimen represents a new species within the genus Thalassometra:Thalassometra brachia sp.nov.This new species was collected at a depth of 688 m and is characterized by the dome-like centrodorsal,large number of arms(43 in total),irregularly arranged sockets with three per radial area,P 2 and P 3,similar in size and character and smaller than P 1,spinous median carination on the first and second ossicles of the division series and on the first two brachials,and dense spicules in brachial bases.展开更多
To explore the geochemical characteristics and genesis of the elements in ferromanganese nodules from the Northwest Pacific,this study analyses the mineral composition,elemental content,occurrence phase and genetic me...To explore the geochemical characteristics and genesis of the elements in ferromanganese nodules from the Northwest Pacific,this study analyses the mineral composition,elemental content,occurrence phase and genetic mechanisms of samples by X-ray diffraction(XRD),inductively coupled plasma-optical emission spectrometry(ICP-OES),inductively coupled plasma-mass spectrometry(ICP-MS)and phase analysis methods.The results show that ferromanganese nodules are mainly hydrogenetic,and Mn/Fe content ratio ranges from 0.95 to 2.05.The major minerals are vernadite(δ-MnO_(2))and amorphous ferric oxyhydroxide(FeOOH),and the secondary minerals include todorokite,birnessite,quartz and plagioclase.Ferromanganese nodules contain high contents of Co(0.24%-0.42%),Cu(0.23%-0.73%),Ni(0.33%-0.86%)and rare earth elements(REEs,1192-1990μg/g),which have positive Ce and negative Y anomalies but no Eu anomaly.A cluster analysis suggests that the elements in ferromanganese nodules can be divided into three groups:hydrogenetic components,including Fe,Ti,Zr,P,Pb,Co,Ba,Sr,V and REEs;diagenetic components,including Mn,Ni,Mg,Zn and Cu;and detrital components,including Al,Na,K and Ca.According to chemical leaching,ferromanganese nodules can be divided into four phases:Na,Ca,Mg and Sr are mainly enriched in the carbonate phase;Mn,Co,Ni and Ba are mainly enriched in the Mn-oxide phase;Fe,P,Ti,Cu,Pb,V,Zn,Zr and REEs are mainly enriched in the Fe-oxide phase;and Al and K are mainly enriched in the residual phase.A combination of the two different methods reveal selective enrichment of metal elements from seawater by ferromanganese nodules,featuring multisource mineralization.Moreover,through ion exchange and adsorption,approximately 71.2%of REEs are enriched in the Fe-oxide phase,15.4%in the Mn-oxide phase and 12.4%in the residual phase,while REE contents in the carbonate phase are relatively low.In addition,under the oxic conditions of seawater,the oxidation of soluble Ce^(3+)to insoluble CeO_(2)together with Fe-Mn minerals results in Ce enrichment in ferromanganese nodules.This study provides a reference for the metallogenesis of ferromanganese nodules from the Northwest Pacific.展开更多
Against the backdrop of climate change,the activity of tropical cyclones(TCs)has captured widespread attention.Observational datasets indicate a declining trend in the genesis longitude of western North Pacific(WNP)TC...Against the backdrop of climate change,the activity of tropical cyclones(TCs)has captured widespread attention.Observational datasets indicate a declining trend in the genesis longitude of western North Pacific(WNP)TCs.This study investigates the zonal changes of WNP TCs with CMIP6-HighResMIP models.These models capture the genesis density of WNP TCs fairly well.The results reveal a westward shift in TC genesis longitude.This trend is associated with the significant reduction in the TC frequency over the southeastern WNP.The study also discusses changes in large-scale circulation patterns and the impact of the strengthening Pacific Walker circulation.展开更多
Marine heatwaves(MHWs)are extreme ocean events characterized by anomalously warm upper-ocean temperatures,posing significant threats to marine ecosystems.While various factors driving MHWs have been extensively studie...Marine heatwaves(MHWs)are extreme ocean events characterized by anomalously warm upper-ocean temperatures,posing significant threats to marine ecosystems.While various factors driving MHWs have been extensively studied,the role of ocean salinity remains poorly understood.This study investigates the influence of salinity on the major 2013-2014 MHW event in the Northeast Pacific using reanalysis data and climate model outputs.Our results show that salinity variabilities are crucial for the development of the MHW event.Notably,a significant negative correlation exists between sea surface temperature anomalies(SSTAs)and sea surface salinity anomalies(SSSAs)during the MHW,with the SSSAs emerging simultaneously with SSTAs in the same area.Negative salinity anomalies(SAs)result in a shallower mixed layer,which suppresses vertical mixing and thus sustains the upper-ocean warming.Moreover,salinity has a greater impact on mixed layer depth anomalies than temperature.Model sensitivity experiments further demonstrate that negative SAs during MHWs amplify positive SSTAs by enhancing upper-ocean stratification,intensifying the MHW.Additionally,our analysis indicates that the SAs are predominantly driven by local freshwater flux anomalies,which are mainly induced by positive precipitation anomalies during the MHW event.展开更多
基金supported by the National Key Research and Development Program of China [grant number 2023YFF0807000]。
文摘Based on datasets from the International Best-Track Archive for Climate Stewardship(IBTrACS)and the fifth major global reanalysis produced by ECMWF(ERA5),the authors found that 29%of tropical cyclones(TCs)in the western North Pacific underwent extratropical transition(ET)from 1979 to 2022,with the frequency of ET events showing a slow decreasing trend.The extratropical transition tropical cyclones(ETCs)are classified into four clusters using the k-means clustering method based on their track patterns:recurving ETCs,westward ETCs,northwestward ETCs,and abnormal track ETCs.The transition process of recurving ETCs mostly occurs after the recurvature is completed,while 63.7%of the westward ETCs complete their transition after landfall.Abnormal track ETCs undergo transition over high-latitude oceans.Northwestward ETCs have the longest duration and slowest transition speed during the ET period,resulting in a prolonged impact.The ET process occurs at the edges of the western Pacific subtropical high(WPSH),with higher frequency during westward extension and lower during eastward retreat.While westward ETCs transition through surface friction effects,others complete ET in the northwest baroclinic zone of the WPSH.
基金supported by the National Key Research and Development Program of China[grant number 2020YFA0608000]。
文摘The Northwest Pacific subtropical high(NWPSH)significantly affects East Asian weather and climate,rendering the prediction of its intensity and location critically important.This study aims to evaluate the performance of the Convolutional Long and Short-Term Memory(ConvLSTM)model for predicting the summertime 500 hPa geopotential height and NWPSH intensity and area at a lead time of three months,and to compare it with the dynamical models of the Nanjing University of Information Science and Technology Climate Forecast System(NUIST-CFS1.0)and the Canadian Seasonal to Interannual Prediction System Version 2(CanSIPSv2).The mean latitude-weighted RMSE(RMSE_(w)),anomaly correlation coefficient(ACC),and NWPSH indices are used as evaluation metrics.For both summer mean and monthly prediction,the ConvLSTM model outperforms the two dynamical models in terms of RMSE_(w) and ACC for the 500 hPa geopotential height over the western Pacific region.The correlation coefficients between the NWPSH intensity index predicted by the ConvLSTM model and the observations are higher than those obtained from the two dynamical models.Regarding the NWPSH area index,the ConvLSTM model shows more stable performance.Particularly in August,the improvement of the ConvLSTM model compared to the two dynamical models is more significant,indicating the robust capability in capturing late-summer circulation patterns.Therefore,the ConvLSTM model demonstrates significant potential for summer NWPSH prediction,offering a new perspective and approach for climate prediction in this region.
基金supported by the National Natural Science Foundation of China(Grant No.42405029).
文摘Based on reanalysis data and CMIP6 simulations,this study investigates the distinct responses of the cross-equatorial flows(CEFs)over the Maritime Continent(MC)under the simultaneous summer condition of two types of ENSO:central Pacific(CP)and eastern Pacific(EP).Results indicate that CP ENSO tends to exert stronger impacts on CEF.In CP ENSO years,significant lower-level southerly anomalies can be observed across all CEF branches adjacent to MC,accompanied by broader and deeper upper-level northerly anomalies,indicating a well-organized strengthening of both upper-and lowerlevel CEFs.In contrast,CEF anomalies in EP ENSO years tend to be weaker,with significant meridional wind anomalies confined to the east of MC.The disparities in the CEF responses can be elucidated from the perspective of convection over MC,a crucial factor in triggering CEF.In CP ENSO years,westward-leaning sea surface temperature(SST)anomalies result in a distinct cooling in MC and suppressed convection above,driving pronounced CEF anomalies.Conversely,the absence of such organized SST cooling during EP ENSO results in weaker convective forcing and subdued CEF responses.Furthermore,historical simulations from 48 CMIP6 models are utilized to validate the observational findings.Results show that model simulations can successfully reproduce the stronger impacts of CP ENSO,with a remarkable intermodel consistency.This research contributes toward a comprehensive understanding of the diversity in the relationship between CEF and ENSO types,and has implications for seasonal forecasting of CEF variability.
文摘This paper expands Prasenjit Duara’s proposal that Asian religions and philosophies offer hope for a sustainable future.After outlining Duara’s sociology of history that describes the crisis of global modernity in terms of three global changes,namely the rise of non-western nations,the crisis of climate change,and the decline of religious or transcendent sources of authority,Duara proposes that grassroots organizations coupled with Asian religious and philosophical beliefs and practices offer different ways of understanding the relationship between the person and the environment,and between our universal-planetary interests and our national interests.Drawing from Asian and Pacific indigenous teachings,I propose a type of depth ecology called“existential parity”that all things and creatures have value,generating a moral corollary called the“existential commitment”that humans take responsibility for the environment and each other.The existential commitment offers an environmental ethics that promotes sustainable agriculture to feed the world’s population.Pacific agroforestry practices can be implemented in urban settings to help mitigate climate change and food shortages.
基金supported by the National Natural Science Foundation of China(Nos.42406256,42376034,and 42430402)the Qingdao Postdoctoral Application Research Project(No.QDBSH20220202152)+1 种基金the National Key R&D Program of China(No.2018YFA0605701)the Chinese Arctic and Antarctic Administration(No.IRASCC2020-2022-02-01-03)。
文摘The subantarctic mode water(SAMW)represents a large water mass in the Southern Ocean.This body of water forms through deep convection(subduction)in winter and contributes to the uptake and storage of anthropogenic heat.However,its longterm changes in subduction rate and volume in response to shifting climate conditions are unclear.In this study,we investigated the long-term trend of the subduction rate and volume of the South Pacific–SAMW(SPSAMW)using Simple Ocean Data Assimilation outputs during 1980–2017.The results show the overall increasing trend of the subduction rate of the SPSAMW.The increased subduction of the SPSAMW directly contributes to the volume variation in the SPSAMW.The increased subduction in the South Pacific reached(0.28±0.16)Sv-1 per year,which explains nearly 68%of the volume increase in the SPSAMW.This variability in the SPSAMW reflects alterations in the overlying atmosphere.The positive to negative phase change of the Interdecadal Pacific Oscillation(IPO)in 1980–2017 deepened the Amundsen Sea Low(ASL)via atmospheric teleconnections over the South Pacific.Further analysis reveals that the increased westerly winds during the deepening of ASL resulted in more cold water transport from the south,which deepened the winter mixed layer and thus increased subduction and volume within the SPSAMW subduction region.This finding suggests the association of the long-term trends of SPSAMW subduction and volume with the phase change of the IPO.
基金supported by the CAS Strategic Priority Research Program(No.XDB0760102),the Ministry of Science and Technology of China(No.2022YFF0802501)the Major Science and Technology Infrastructure Maintenance and Transformation Project of the Chinese Academy of Sciences,Shanghai Science and Technology Innovation Action Plan-Phospherus Project(No.23YF1426200)the National Key Research and Development Program of China(No.2024YFE0212200).
文摘In winter 2018,an aerosol physicochemical experiment was conducted in the Western Pacific Ocean(WPO)aboard the Research Vessel KEXUE of Chinese Academy of Sciences.This study systematically investigated both natural and anthropogenic effects on marine aerosols optical properties,as well as the applicability of multi-satellite products and IMPROVE equation.The averaged aerosol optical depth(AOD500 nm)was 0.31±0.16 andÅngström exponent440–675 nm was 0.29±0.30.In offshore China,significant anthropogenic emissions affected the marine environment.In remote WPO,dust aerosols transported from northern China,Siberia,Central Asia,and those settling from the upper troposphere originating from north Africa,Arabian peninsula,and western India,were dominant.The spatial trends of AOD were opposite in the mid-latitude and southern seas of WPO.The highest AOD,0.32±0.23,appeared along the coast of South Asia at mid-latitude,decreasing from offshore seas to remote oceans.In low-latitude and equatorial seas,AOD significantly increased from coast to remote oceans.Ångström exponent dropped significantly from the coast to remote oceans as anthropogenic influence diminished across the entire WPO.Correlation analysis showed that both MODIS-C6 and Himawari AOD prod-ucts showed similar applicability in coastal urban areas,while Himawari AOD is highly recommended for coastal background and marine environment due to its finer resolution.The extinction coefficient derived from PM_(2.5) chemical compositions using IMPROVE algorithm exhibited a significant correlation(R^(2)=0.58)with the con-currently measured AOD in the absence of long-distance transport,suggesting that the IMPROVE is a reasonable proxy of the columnar average of marine aerosol extinctions free from transport influences.
基金supported by the National Natural Science Foundation of China(Grant Nos:42130801,41430211,90814006,and 42072226)the“Deep-time Digital Earth”Science and Technology Leading Talents Team Funds for the Central Universities for the Frontiers Science Center for Deep-time Digital Earth,CUGB(Fundamental Research Funds for the Central UniversitiesGrant No:2652023001).
文摘How the subduction direction of the Paleo-Pacific plate beneath the Eurasian plate changes in the Early Cretaceous remains highly controversial due to the disappearance of the subducted oceanic plate.Intraplate deformation structures in the east Asian continent,however,provide excellent opportunities for reconstructing paleostress fields in continental interior in relation to the Paleo-Pacific/Eurasian plate interaction.Anisotropy of magnetic susceptibility(AMS),geological,and geochronological analyses of post-kinematic mafic dykes intruding the detachment fault zone of the Wulian metamorphic core complex(WL MCC)in Jiaodong Peninsula exemplify emplacement of mantle-sourced dykes in a WNW-ESE(301°-121°)oriented tectonic extensional setting at ca.120 Ma.In combination with the results from our previous kinematic analysis of the MCC,a ca.21°clockwise change in the direction of intraplate extension is obtained for early(135-122 Ma)extensional exhumation of the MCC to late(122-108 Ma)emplacement of the dykes.Such a change is suggested to be related to the variation in subduction direction of the Paleo-Pacific plate beneath the Eurasian plate,from westward(pre-122 Ma)to west-northwestward(post-122 Ma).
基金funded by a Project from China Southern Power Grid Company Ltd.(Nos.ZBKJXM20232481 and ZBKJXM20232482)。
文摘This study investigates the distinct impacts of eastern Pacific(EP)and central Pacific(CP)El Niño events on winter shortwave solar radiation(SSR)in southern China,revealing different spatial distributions and underlying mechanisms.The results show that,during the developing winter of EP El Niño,significant SSR reductions occur in southwestern China and the east coast of southern China due to a strong,zonally extended Northwest Pacific anticyclone that transports moisture from the tropical Northwest Pacific and North Indian Ocean,while the northeast of southern China experiences a weak increase in SSR.In contrast,during the developing winter of CP El Niño,SSR decreases in the east of southern China with a significant decrease in the lower basin of the Yangtze River but an increase in the west of southern China with a remarkable increase in eastern Yunnan.The pronounced east-west dipole pattern in SSR anomalies is driven by a meridionally elongated Northwest Pacific anticyclone,which enhances northward moisture transport to the east of southern China while leaving western areas drier.Further research reveals that distinct moisture anomalies during the developing winter of EP and CP events result in divergent SSR distributions across southern China,primarily through modulating the total cloud cover.These findings highlight the critical need to differentiate between El Niño types when predicting medium and long-term variability of radiation in southern China.
基金supported by the National Natural Science Foundation of China [grant number 42088101]。
文摘During the boreal summer,intraseasonal oscillations exhibit significant interannual variations in intensity over two key regions:the central-western equatorial Pacific(5°S-5°N,150°E-150°W)and the subtropical Northwestern Pacific(10°-20°N,130°E-175°W).The former is well-documented and considered to be influenced by the ENSO,while the latter has received comparatively less attention and is likely influenced by the Pacific Meridional Mode(PMM),as suggested by partial correlation analysis results.To elucidate the physical processes responsible for the enhanced(weakened)intraseasonal convection over the subtropical northwestern Pacific during warm(cold)PMM years,the authors employed a moisture budget analysis.The findings reveal that during warm PMM years,there is an increase in summer-mean moisture over the subtropical northwestern Pacific.This increase interacts with intensified vertical motion perturbations in the region,leading to greater vertical moisture advection in the lower troposphere and consequently resulting in convective instability.Such a process is pivotal in amplifying intraseasonal convection anomalies.The observational findings were further verified by model experiments forced by PMM-like sea surface temperature patterns.
基金National Key R&D Program of China(2022YFC3004200)Science and Technology Commission of Shanghai Municipality,China(23DZ1204703)。
文摘The duration of the extratropical transition(ET)of tropical cyclones(TCs)is often closely associated with disaster intensity.Therefore,it is essential to understand the key factors that influence ET duration.Using the TC best-track data and reanalysis data,this study investigates the structural characteristics and key influencing factors of ET duration in the western North Pacific(WNP)during 1981–2022.Results show that,compared to TCs that undergo ET rapidly(≤12 h),TCs that experience ET slowly(≥24 h)undergo a more prolonged and complex ET process,maintaining a warm core and an upright structure for extended periods.By contrast,TCs undergoing rapid transition experience structural disintegration within 6–12 h after ET onset.Further analysis reveals that TCs with longer ET durations are characterized by stronger warm cores,more abundant moisture,weaker environmental vertical wind shear,slower translation speeds,and a longer residence time over warmer sea surface temperatures(SSTs),all of which support the maintenance of axisymmetric structures with strong warm cores.Environmental and structural factors,including cold-air intensity,vertical wind shear,TC translation speed,SST,relative humidity,TC intensity,the radius of 17 m s^(-1)wind,mean sea level pressure,and the radius of maximum wind,are found to exist significant correlation with ET duration.Cold-air intensity exhibited the highest correlation(r=–0.35),followed by TC translation speed and SST.A relative importance analysis shows that the environmental factors play a more substantial role than the internal TC structure,accounting for about 19.23%of the variance,with TC translation speed and cold-air effects explaining 11.68%.Based on the nine factors,a statistical forecasting model was developed,which shows considerable skill in predicting ET duration.
基金Science and Technology Commission of Shanghai Municipality,China(23DZ1204703)。
文摘Extratropical transition(ET)is one of the last phases of tropical cyclones(TCs)and corresponds to the structural change from a tropical system to an extratropical system characterized by pronounced asymmetric distributions of heavy rainfall and strong wind.This study analyzes the statistical characteristics of ET events involving TCs over the western North Pacific(WNP)during 1981–2022.The analysis employs the Cyclone Phase Space(CPS)method to evaluate the accuracy of the fifth-generation reanalysis from the European Centre for Medium-Range Weather Forecasts(ERA5)in identifying ET based on different TC center definitions.Results show that defining the TC center by the minimum sea level pressure yields the most accurate ET identification.Subsequently,the study investigates several characteristics of ET events in the WNP.It is found that TCs undergoing ET(ETTCs)primarily form in the region of 125°–155°E,10°–25°N,with ET typically initiating between 30°–40°N and completing between 35°–50°N.These ETTCs predominantly occur from April to December,with peak activity observed from August to October.Additionally,the average duration of the ET process is 18.5 h,with longer durations observed from August to October,displaying a roughly 6-year cycle.Spatially,ET events with longer durations tend to occur at lower latitudes.Correspondingly,TCs initiating their ET phase at lower latitudes are typically stronger and larger,and they also experience longer ET durations.
基金funded by the National Natural Science Foundation of China(Grant Nos.42275140,42230612,91837310,41675041,and 92037000)the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(Grant No.2019QZKK0104)。
文摘The North Pacific storm track(NPST)is a high-frequency area of extratropical cyclones and an important channel for water vapor and energy transfer between low and mid–high latitudes.Previous weather and dynamic studies in this region have made significant progress,but due to the lack of ocean surface rainfall observation data,there is a lack of statistical research on precipitation in this area.In this study,statistical research on the spatiotemporal distribution characteristics of NPST rainfall was conducted based on GPM DPR(Global Precipitation Measurement Dual-frequency Precipitation Radar)observation data and ERA5 atmospheric parameters,and analysis and explanations are provided based on the atmospheric parameters.The study found that,compared to low-pressure systems,pressure gradients have a greater impact on cyclone activity and rainfall distribution.This feature,along with the meridional distribution of high atmospheric water vapor in the North Pacific Ocean and low in the north,collectively leads to the offset of high-frequency rainfall areas relative to storm tracks.The distribution of sea surface temperatures in the North Pacific Ocean affects the zonal distribution of storm tracks,causing weather disturbances and precipitation along the storm tracks to exhibit a northward extension from west to east.This study deepens our understanding of the role of NPST in global-scale water vapor and energy balance,and is of great significance for improving the prediction accuracy of climate models with respect to rainfall generated by extratropical cyclones.
基金Guangdong Major Project of Basic and Applied Basic Research(2020B0301030004)National Natural Science Foundation of China(41875114)Science and Technology Commission of Shanghai Municipality,China(23DZ1204703)。
文摘The rapid intensification(RI)magnitude of tropical cyclones(TCs)over the western North Pacific(WNP)exhibits significant interannual variability and is influenced by multiple factors across various scales.These factors primarily include:interannual factors—sea surface temperature(SST)in key regions of the WNP,eastern Indian Ocean SST,El Niño-Southern Oscillation(ENSO),South Pacific Subtropical Dipole(SPSD),and western Pacific teleconnection;decadal factors—Atlantic Multidecadal Oscillation(AMO)and Pacific Decadal Oscillation(PDO);and longer-term factor—global warming.This study systematically analyzes these factors and their potential impacts,quantitatively assessing their relative importance.A statistical prediction model for the WNP TC-RI magnitude is developed based on ridge regression methods.The results indicate that the influence of these factors on the RI magnitude is closely related to the large-scale thermodynamic and dynamic conditions.Among them,the SPSD plays the most critical role in the interannual variability of the RI magnitude,followed by global warming and the AMO.Further analysis reveals that the statistical prediction model based on multiple factors demonstrates good predictive skill for the interannual variability of the TC RI magnitude.
基金supported by the National Natural Science Foundation of China(Grant No.42030410)the Laoshan Laboratory(Grant Nos.LSKJ202202404 and LSKJ202202403)+1 种基金the Startup Foundation for Introducing Tal-ent of NUIST,Jiangsu Innovation Research Group(Grant No.JSS-CTD202346)the Jiangsu Funding Program for Excellent Post-doctoral Talent(Grant No.2023ZB690).
文摘Bomb cyclones are rapidly deepening extratropical cyclones predominantly found in midlatitude regions.These extreme events are particularly frequent over the North Pacific(NP),posing significant societal and environmental risks.Currently,our understanding of the variability of bomb cyclones over the NP remains limited.This study analyzes the variations in multiple NP bomb cyclone characteristics from 1980 onward using four major reanalysis datasets.The results show a weakening trend of bomb cyclones since the beginning of the 21st century,which is characterized by significant reductions in maximum near-surface wind speeds,increases in minimum sea level pressure,and slower deepening rates.Further analysis reveals that the observed weakening trend of bomb cyclones is closely linked to a reduction in maximum 850 hPa Eady growth rate,driven primarily by reduced vertical wind shear within the 30°-45°N latitudinal band.Furthermore,our findings indicate that the Aleutian Low acts to modulate the meridional air temperature gradient over the midlatitude NP,which is corroborated by climate model outputs.This modulation provides a pathway for the Aleutian Low to affect low-level baroclinicity and thus bomb cyclone characteristics.These results have important implications for future projections of bomb cyclone activity over the NP,aiding in risk assessment and mitigating the impacts of these extreme events.
基金supported by National Natural Science Foundation of China under(Grant No.U2142206)the Shanghai Natural Science Foundation(21ZR1477300)+1 种基金Shanghai Science and Technology Commission Project(23DZ1204701)National Natural Science Foundation of China(Grant No.42075056)。
文摘This study investigates the size characteristics and related temporal variations of tropical cyclones(TCs)over the Western North Pacific(WNP)and those affecting East China(EC)using Joint Typhoon Warning Center(JTWC)data during 2001-20.The average size of EC TCs is found to be similar to that over the WNP.Furthermore,the annual maximum lifetime maximum size(LMS)of EC TCs shows a statistically significant increasing trend,implying a more severe impact on the EC region.Composite analyses of intensity and size variation over the entire lifetime of TCs,before and after re-curvature,and before and after rapid intensification(RI),show that there are significant differences between them in some key areas:(1)The intensity begins to rapidly decrease after the TC has reached its highest intensity,but the size remains quasi-constant;(2)When a TC recurves south of 15°N or north of 30°N,the variation trend for both intensity and size are broadly similar before and after curvature,but their variation trends are opposite when the recurvature occurs between 15°-30°N;(3)After RI,the intensity reaches its peak value within 24 h,whereas the size reaches its LMS after30-48 h.A significant correlation is also found between the rate of change in intensity and that of size during the development stage,with a correlation coefficient of 0.67 and 0.73 for TCs in the WNP and EC,respectively.However,no significant correlation exists during the weakening stage.
基金National Natural Science Foundation of China,No.42225105,No.42201176National Natural Science Foundation of China Basic Science Center for Tibetan Plateau Earth System Project(NSFC BSCTPES Project),No.41988101。
文摘Tropical cyclones(TCs)have profound impacts on socioeconomic conditions and pose substantial risks to lives and property.However,it is still unclear whether the multitimescale changes in TC activity over the past 2000 years in the Northwestern Pacific(NWP)were regulated by Asian dust forcing.Here,we assessed the impact of Asian dust on TC activity using observational data and reconstructed records from the northern and southern NWP.Our correlation analysis of instrumental data from 1954 to 2017 reveals no significant relationship between observed TC activity and Asian dust forcing.Furthermore,we found a meridional dipole pattern of TC variation across the NWP in observations and reconstructions.These finding challenges current explanations that are based on the synchronous changes in TC activity and Asian dust forcing.Alternatively,we propose that the Western Pacific Subtropical High(WPSH)plays a crucial role in driving these meridional dipole patterns in TC variations,as supported by observations and reconstructions.The southwestward extension of an enhanced WPSH intensifies easterly flow,steering TCs westward along its southern edge.This leads to more TC activity in the southern NWP but less in the north,and vice versa when the WPSH is weakened.With the expected strengthening of the WPSH due to global warming,it is vital to consider its impact on NWP TC activity for effective risk-mitigation strategies.
基金Supported by the Science and Technology Innovation Project of Laoshan Laboratory(No.LSKJ 202203100)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB 42000000)。
文摘During the expedition to an unnamed seamount of Caroline Ridge in the northwest Pacific Ocean,one Thalassometra specimen was sampled,and careful morphological assessment suggested that this specimen represents a new species within the genus Thalassometra:Thalassometra brachia sp.nov.This new species was collected at a depth of 688 m and is characterized by the dome-like centrodorsal,large number of arms(43 in total),irregularly arranged sockets with three per radial area,P 2 and P 3,similar in size and character and smaller than P 1,spinous median carination on the first and second ossicles of the division series and on the first two brachials,and dense spicules in brachial bases.
基金The Fund of Laoshan Laboratory under contract No.LSKJ202203602the National key R&D Program of China under contract No.2022YFC2803600the Taishan Scholarship from Shandong Province.
文摘To explore the geochemical characteristics and genesis of the elements in ferromanganese nodules from the Northwest Pacific,this study analyses the mineral composition,elemental content,occurrence phase and genetic mechanisms of samples by X-ray diffraction(XRD),inductively coupled plasma-optical emission spectrometry(ICP-OES),inductively coupled plasma-mass spectrometry(ICP-MS)and phase analysis methods.The results show that ferromanganese nodules are mainly hydrogenetic,and Mn/Fe content ratio ranges from 0.95 to 2.05.The major minerals are vernadite(δ-MnO_(2))and amorphous ferric oxyhydroxide(FeOOH),and the secondary minerals include todorokite,birnessite,quartz and plagioclase.Ferromanganese nodules contain high contents of Co(0.24%-0.42%),Cu(0.23%-0.73%),Ni(0.33%-0.86%)and rare earth elements(REEs,1192-1990μg/g),which have positive Ce and negative Y anomalies but no Eu anomaly.A cluster analysis suggests that the elements in ferromanganese nodules can be divided into three groups:hydrogenetic components,including Fe,Ti,Zr,P,Pb,Co,Ba,Sr,V and REEs;diagenetic components,including Mn,Ni,Mg,Zn and Cu;and detrital components,including Al,Na,K and Ca.According to chemical leaching,ferromanganese nodules can be divided into four phases:Na,Ca,Mg and Sr are mainly enriched in the carbonate phase;Mn,Co,Ni and Ba are mainly enriched in the Mn-oxide phase;Fe,P,Ti,Cu,Pb,V,Zn,Zr and REEs are mainly enriched in the Fe-oxide phase;and Al and K are mainly enriched in the residual phase.A combination of the two different methods reveal selective enrichment of metal elements from seawater by ferromanganese nodules,featuring multisource mineralization.Moreover,through ion exchange and adsorption,approximately 71.2%of REEs are enriched in the Fe-oxide phase,15.4%in the Mn-oxide phase and 12.4%in the residual phase,while REE contents in the carbonate phase are relatively low.In addition,under the oxic conditions of seawater,the oxidation of soluble Ce^(3+)to insoluble CeO_(2)together with Fe-Mn minerals results in Ce enrichment in ferromanganese nodules.This study provides a reference for the metallogenesis of ferromanganese nodules from the Northwest Pacific.
基金supported by a key project of the National Natural Science Foundation of China[grant number 42192563]。
文摘Against the backdrop of climate change,the activity of tropical cyclones(TCs)has captured widespread attention.Observational datasets indicate a declining trend in the genesis longitude of western North Pacific(WNP)TCs.This study investigates the zonal changes of WNP TCs with CMIP6-HighResMIP models.These models capture the genesis density of WNP TCs fairly well.The results reveal a westward shift in TC genesis longitude.This trend is associated with the significant reduction in the TC frequency over the southeastern WNP.The study also discusses changes in large-scale circulation patterns and the impact of the strengthening Pacific Walker circulation.
基金The Laoshan Laboratory under contract Nos LSKJ202202403 and LSKJ202202402the National Natural Science Foundation of China under contract Nos 42030410 and 42406202+3 种基金the Natural Science Foundation of Jiangsu Province under contract No.BK20240718the Startup Foundation for Introducing Talent of Nanjing University of Information Science and Technologythe Jiangsu Innovation Research Group under contract No.JSSCTD202346the Jiangsu Funding Program for Excellent Postdoctoral Talent under contract No.2023ZB690.
文摘Marine heatwaves(MHWs)are extreme ocean events characterized by anomalously warm upper-ocean temperatures,posing significant threats to marine ecosystems.While various factors driving MHWs have been extensively studied,the role of ocean salinity remains poorly understood.This study investigates the influence of salinity on the major 2013-2014 MHW event in the Northeast Pacific using reanalysis data and climate model outputs.Our results show that salinity variabilities are crucial for the development of the MHW event.Notably,a significant negative correlation exists between sea surface temperature anomalies(SSTAs)and sea surface salinity anomalies(SSSAs)during the MHW,with the SSSAs emerging simultaneously with SSTAs in the same area.Negative salinity anomalies(SAs)result in a shallower mixed layer,which suppresses vertical mixing and thus sustains the upper-ocean warming.Moreover,salinity has a greater impact on mixed layer depth anomalies than temperature.Model sensitivity experiments further demonstrate that negative SAs during MHWs amplify positive SSTAs by enhancing upper-ocean stratification,intensifying the MHW.Additionally,our analysis indicates that the SAs are predominantly driven by local freshwater flux anomalies,which are mainly induced by positive precipitation anomalies during the MHW event.
