The Arctic and Antarctica are important components of the Earth system,and the snow and ice over the polar regions make the interactions between the spheres there extremely sensitive to climate change,with an amplifyi...The Arctic and Antarctica are important components of the Earth system,and the snow and ice over the polar regions make the interactions between the spheres there extremely sensitive to climate change,with an amplifying effect on climate warming.Polar regions are the forefront of global climate and ecosystem changes.More than half of the identified climate tipping elements in our planet occur in the polar regions,with the losses of Arctic sea ice,Greenland ice sheet,permafrost,and western Antarctic ice sheet,being considered as tipping elements with global impacts that have already occurred(McKay et al.,2022).These changes in the polar regions affect the heat and material transfer,water and carbon cycles,as well as biological diversity at a global scale,closely related to global sustainable development.Therefore,polar regions are also considered the limiting factors in achieving the United Nations Sustainable Development Goals(Li et al.,2025).展开更多
Because of their effect on climate,carbon dioxide(CO_(2)),methane(CH_(4)),nitrous oxide(N_(2)O),and dimethylsulfide(DMS)are collectively designated as climate-relevant gases(CRGs).CO_(2),CH_(4),and N_(2)O are greenhou...Because of their effect on climate,carbon dioxide(CO_(2)),methane(CH_(4)),nitrous oxide(N_(2)O),and dimethylsulfide(DMS)are collectively designated as climate-relevant gases(CRGs).CO_(2),CH_(4),and N_(2)O are greenhouse gases contributing to global warming(positive climate feedback).Conversely,DMS is involved in the generation of cloud condensation nuclei,thus in the formation of clouds that cool the boundary layer by reflecting incoming solar radiation(negative climate feedback).Despite their scarcity,field observations and model results have demonstrated the essential role of polar oceans in the budget of CRGs.For example,the Southern Ocean represents a substantial CO_(2)sink but a source of N_(2)O and DMS,thereby exerting variable feedback on climate change.Unfortunately,because of the severe environmental conditions at polar latitudes,substantial knowledge gaps remain,for example on the mechanisms underlying CRGs formation or on the strength and distribution of their sources and sinks in the Southern and Arctic Oceans.Here,we review the most recent research results on the distribution,production-loss processes,and abundance variations of CRGs in the polar oceans.We list the remaining knowledge gaps and propose future directions of research on CRGs in the polar oceans,as a useful reference for future studies.展开更多
The Indonesian Throughflow(ITF)plays important roles in global ocean circulation and climate systems.Previous studies suggested the ITF interannual variability is driven by both the El Niño-Southern Oscillation(E...The Indonesian Throughflow(ITF)plays important roles in global ocean circulation and climate systems.Previous studies suggested the ITF interannual variability is driven by both the El Niño-Southern Oscillation(ENSO)and the Indian Ocean Dipole(IOD)events.The detailed processes of ENSO and/or IOD induced anomalies impacting on the ITF,however,are still not clear.In this study,this issue is investigated through causal relation,statistical,and dynamical analyses based on satellite observation.The results show that the driven mechanisms of ENSO on the ITF include two aspects.Firstly,the ENSO related wind field anomalies driven anomalous cyclonic ocean circulation in the western Pacific,and off equatorial upwelling Rossby waves propagating westward to arrive at the western boundary of the Pacific,both tend to induce negative sea surface height anomalies(SSHA)in the western Pacific,favoring ITF reduction since the develop of the El Niño through the following year.Secondly,the ENSO events modulate equatorial Indian Ocean zonal winds through Walker Circulation,which in turn trigger eastward propagating upwelling Kelvin waves and westward propagating downwelling Rossby waves.The Rossby waves are reflected into downwelling Kelvin waves,which then propagate eastward along the equator and the Sumatra-Java coast in the Indian Ocean.As a result,the wave dynamics tend to generate negative(positive)SSHA in the eastern Indian Ocean,and thus enhance(reduce)the ITF transport with time lag of 0-6 months(9-12 months),respectively.Under the IOD condition,the wave dynamics also tend to enhance the ITF in the positive IOD year,and reduce the ITF in the following year.展开更多
The annual, interannual and inter-decadal variability of convection intensity of South China Sea (SCS) summer monsoon and air-sea temperature difference in the tropical ocean is analyzed, and their relationship is dis...The annual, interannual and inter-decadal variability of convection intensity of South China Sea (SCS) summer monsoon and air-sea temperature difference in the tropical ocean is analyzed, and their relationship is discussed using two data sets of 48-a SODA (simple ocean data assimilation) and NCEP/NCAR. Analyses show that in wintertime Indian Ocean (WIO), springtime central tropical Pacific (SCTP) and summertime South China Sea-West Pacific (SSCSWP), air-sea temperature difference is significantly associated with the convection intensity of South China Sea summer monsoon. Correlation of the inter-decadal time scale (above 10 a) is higher and more stable. There is inter-decadal variability of correlation in scales less than 10 a and it is related with the air-sea temperature difference itself for corresponding waters. The inter-decadal variability of the convection intensity during the South China Sea summer monsoon is closely related to the inter-decadal variability of the general circulation of the atmosphere. Since the late period of the 1970s, in the lower troposphere, the cross-equatorial flow from the Southern Hemisphere has intensified. At the upper troposphere layer, the South Asian high and cross-equatorial flow from the Northern Hemisphere has intensified at the same time. Then the monsoon cell has also strengthened and resulted in the reinforcing of the convection of South China Sea summer monsoon.展开更多
An ideal and simple formulation is successfully derived that well represents a quasi-linear relationship found between the domain-averaged water vapor, Q （ram）, and temperature, T （K）, fields for the three tropica...An ideal and simple formulation is successfully derived that well represents a quasi-linear relationship found between the domain-averaged water vapor, Q （ram）, and temperature, T （K）, fields for the three tropical oceans （i.e., the Pacific, Atlantic and Indian Oceans） based on eleven GEOS-3 [Goddard Earth Observing System （EOS） Version-3] global re-analysis monthly products. A Q - T distribution analysis is also performed for the tropical and extra-tropical regions based on in-situ sounding data and numerical simulations [GEOS-3 and the Goddard Cumulus Ensemble （GCE） model]. A similar positively correlated Q - T distribution is found over the entire oceanic and tropical regions; however, Q increases faster with T for the former region. It is suspected that the tropical oceans may possess a moister boundary layer than the Tropics. The oceanic regime falls within the lower bound of the tropical regime embedded in a global, curvilinear Q - T relationship. A positive correlation is also found between T and sea surface temperature （SST）; however, for one degree of increase in T, SST is found to increase 1.1 degrees for a warmer ocean, which is slightly less than an increase of 1.25 degrees for a colder ocean. This seemingly indicates that more （less） heat is needed for an open ocean to maintain an air mass above it with a same degree of temperature rise during a colder （warmer） season [or in a colder （warmer） region]. Q and SST are also found to be positively correlated. Relative humidity （RH） exhibits similar behaviors for oceanic and tropical regions. RH increases with increasing SST and T over oceans, while it increases with increasing T in the Tropics. RH, however, decreases with increasing temperature in the extratropics. It is suspected that the tropical and oceanic regions may possess a moister local boundary layer than the extratropics so that a faster moisture increase than a saturated moisture increase is favored for the former regions. T, Q, saturated water vapor, RH, and SST are also examined with regard to the warm and cold ＂seasons＂ over individual oceans. The Indian Ocean warm season dominates in each of the five quantities, while the Atlantic Ocean cold season has the lowest values in most categories. The higher values for the Indian Ocean may be due to its relatively high percentage of tropical coverage compared to the other two oceans. However, Q is found to increase faster for colder months from individual oceans, which differs from the general finding in the global Q - T relationship that Q increases slower for a colder climate. The modified relationship may be attributed to a possible seasonal （warm and cold） variability in boundary layer depth over oceans, or to the small sample size used in each individual oceanic group.展开更多
As one of the prominent landforms in the Zhurong landing region,mesas are geological features with flat tops and steep marginal cliffs.The mesas are widely distributed along the dichotomy boundary.There are various in...As one of the prominent landforms in the Zhurong landing region,mesas are geological features with flat tops and steep marginal cliffs.The mesas are widely distributed along the dichotomy boundary.There are various interpreted origins proposed for the mesas,such as the erosion of sedimentary layers,tuyas eruptions,or surface collapse due to the catastrophic release of groundwater.We investigate the detailed morphological characteristics of the mesas on the Late Hesperian Lowland unit within the Utopia Planitia.We observe morphological evidence for both the ice-bearing interior mesas and the sedimentary origin,including(1)small pits on the crater wall and mesa cliff formed by the release of volatiles like ice;(2)lobate flows at the base of mesas formed by the melting of subsurface ice;(3)layered mesas indicating sedimentary origin;(4)grooves on the top surface of mesas formed by the volumetric compaction of sedimentary deposits.The results indicate that the mesas in the study area are formed by the erosion of sedimentary layers and representative of the Noachian oceanic sediments.We propose an evolutionary model for the mesas.This study will provide some insights into future research of ancient ocean hypothesis of Mars and interesting targets for the exploration of the Zhurong rover.展开更多
A set of absolute geostrophic current(AGC) data for the period January 2004 to December 2012 are calculated using the P-vector method based on monthly gridded Argo profi les in the world tropical oceans. The AGCs agre...A set of absolute geostrophic current(AGC) data for the period January 2004 to December 2012 are calculated using the P-vector method based on monthly gridded Argo profi les in the world tropical oceans. The AGCs agree well with altimeter geostrophic currents, Ocean Surface Current Analysis-Real time currents, and moored current-meter measurements at 10-m depth, based on which the classical Sverdrup circulation theory is evaluated. Calculations have shown that errors of wind stress calculation, AGC transport, and depth ranges of vertical integration cannot explain non-Sverdrup transport, which is mainly in the subtropical western ocean basins and equatorial currents near the Equator in each ocean basin(except the North Indian Ocean, where the circulation is dominated by monsoons). The identifi ed nonSverdrup transport is thereby robust and attributed to the joint effect of baroclinicity and relief of the bottom(JEBAR) and mesoscale eddy nonlinearity.展开更多
The exchange of surface freshwater, heat and moisture fluxes across the air-sea interface strongly influences the oceanic circulation and its variability at all time scales. The goal of this paper is to estimate and e...The exchange of surface freshwater, heat and moisture fluxes across the air-sea interface strongly influences the oceanic circulation and its variability at all time scales. The goal of this paper is to estimate and examine surface freshwater flux at monthly scale exclusively from the Tropical Rainfall Measuring Mission (TRMM) measurements over the tropical oceans for the period of 1998 - 2010. The monthly mean fields of TRMM Microwave Imager (TMI) sea surface temperature (SST), wind speed (WS), and total precipitable water (W) are used to estimate the surface evaporation utilizing the bulk aerodynamics parameterization formula. The merged TRMM Multisatellite Precipitation Analysis (TMPA)-3B43 product is combined with the estimated evaporation to compute the surface freshwater flux. A preliminary comparison of the satellite derived evaporation, precipitation and freshwater flux has been carried out with the Hamburg Ocean Atmosphere Parameters and Fluxes (HOAPS-3) datasets. Also, the estimated evaporation and TMPA-3B43 precipitation are validated with in-situ observations from the moored buoys in the different oceans. The results suggest that the TRMM has great potential to estimate surface freshwater flux for climatological and oceanic hydrological applications.展开更多
AWRITER once comparedSino-foreign cultural ex- changes to a lengthybridge across the oceans of theworld.The Beijing CPAA Cultur- al Entertainment Company,esta- blished in the spring of this year,undoubtedly comes to m...AWRITER once comparedSino-foreign cultural ex- changes to a lengthybridge across the oceans of theworld.The Beijing CPAA Cultur- al Entertainment Company,esta- blished in the spring of this year,undoubtedly comes to many peo- ple’s minds when contemplatingthis remark.The Beijing CPAA Cultural En- tertainment Company is a subsidi- ary of the China Performing ArtsAgency,directly under the Ministryof Culture.It is a self-managed statefirm specializing in international ex-展开更多
(Seventy-third session,Item 78(a)of the provisional agenda,Oceans and the law of the sea,5 September 2018)Summary The present report,which covers the period from 1 September 2017 to 31 August 2018,is submitted pursuan...(Seventy-third session,Item 78(a)of the provisional agenda,Oceans and the law of the sea,5 September 2018)Summary The present report,which covers the period from 1 September 2017 to 31 August 2018,is submitted pursuant to paragraph 366 of General Assembly resolution 72/73,in which the Assembly requested the Secretary-General to prepare a report on developments and issues relating to ocean affairs and the law of the sea,including the implementation of that resolution,for consideration at its seventy-third session.展开更多
In the Galicia Region of the NW Iberian Massif several allochthonous complexes(Cabo Ortegal,Órdenes and Malpica-Tui)contain a rootless Variscan suture that can be traced along the belt,from Iberia to the Bohemian...In the Galicia Region of the NW Iberian Massif several allochthonous complexes(Cabo Ortegal,Órdenes and Malpica-Tui)contain a rootless Variscan suture that can be traced along the belt,from Iberia to the Bohemian Massif in Central Europe.Within these allochthonous complexes are several ophiolite zones bounded by two different continental terranes.There exist in NW Iberia two different ophiolite groups with different chemical compositions,isotopic signatures and structural positions.The Bazar and Vila de Cruces ophiolites,characterized by c.500 Ma protolith ages,represent the Lower Group,whereas the Careón,Purrido and Moeche ophiolites containing 395 Ma maficultramafic sequences represent the Upper Group.This younger group constitutes the most widespread ophiolites in the Variscan Belt.A thick serpentinite mélange(Somozas Mélange)occurring at the base of the Cabo Ortegal Complex also belongs to the ophiolite zones of the Variscan suture.In this paper we describe the Galician ophiolites of the Variscan suture and discuss their tectonic setting of formation.We interpret the generation of the Galician ophiolites within the geodynamic and paleogeographic evolution of the Rheic Ocean and the Pangea supercontinent.展开更多
Pacific-type orogens(fold belts)hosting accretionary complexes are places keeping records of the evolution of paleo-oceans,and formation and transformation of continental crust at their active convergent margins.Pacif...Pacific-type orogens(fold belts)hosting accretionary complexes are places keeping records of the evolution of paleo-oceans,and formation and transformation of continental crust at their active convergent margins.Pacific-type orogeny induces destruction of crustal materials,their subduction to the deep mantle,generation of hydrouscarbonated plumes in the mantle transition zone(MTZ)and its related intra-plate magmatism.We propose a new approach for linking paleo-oceans,active margins and intra-plate magmatism in central and eastern Asia.The approach“stands”on three“whales”:the model of Ocean Plate Stratigraphy(OPS),the parameters of Pacific-type convergent margins and a model of hydrous-carbonated plumes.The OPS model evolved from extensive studies of accretionary complexes in the western Pacific,in particular,in Japan;it allows differentiating oceanic plates of one paleoocean and evaluating their sizes and ages.An important issue for reconstructing the history of paleo-oceans is to estimate major parameters of the Pacific-type convergent margins:accreting vs.eroding,geometrical length,and life time.For the eroding margins we must define major periods of tectonic erosion and transportation of oceanic and continental materials to the deep mantle and evaluate a possibility of their accumulation in the MTZ.All this would allow us to develop a holistic model linking the evolution of paleooceans,the accretion and erosion of oceanic and continental crust materials at Pacific-type convergent margins,mantle metasomatism and intra-plate magmatism.展开更多
A year after finding a job in a construction com- pany in central China＇s Henan Province, Wang Liang was transferred to a coastal village in Ghana. Expecting to be impressed by the African country＇s natural attracti...A year after finding a job in a construction com- pany in central China＇s Henan Province, Wang Liang was transferred to a coastal village in Ghana. Expecting to be impressed by the African country＇s natural attractions, Wang, an enthusiastic foodie, was actually overwhelmed by the abundance of local seafood.展开更多
Changes in ocean heat content(OHC), salinity, and stratification provide critical indicators for changes in Earth’s energy and water cycles. These cycles have been profoundly altered due to the emission of greenhouse...Changes in ocean heat content(OHC), salinity, and stratification provide critical indicators for changes in Earth’s energy and water cycles. These cycles have been profoundly altered due to the emission of greenhouse gasses and other anthropogenic substances by human activities, driving pervasive changes in Earth’s climate system. In 2022, the world’s oceans, as given by OHC, were again the hottest in the historical record and exceeded the previous 2021 record maximum.According to IAP/CAS data, the 0–2000 m OHC in 2022 exceeded that of 2021 by 10.9 ± 8.3 ZJ(1 Zetta Joules = 1021Joules);and according to NCEI/NOAA data, by 9.1 ± 8.7 ZJ. Among seven regions, four basins(the North Pacific, North Atlantic, the Mediterranean Sea, and southern oceans) recorded their highest OHC since the 1950s. The salinity-contrast index, a quantification of the “salty gets saltier–fresh gets fresher” pattern, also reached its highest level on record in 2022,implying continued amplification of the global hydrological cycle. Regional OHC and salinity changes in 2022 were dominated by a strong La Ni?a event. Global upper-ocean stratification continued its increasing trend and was among the top seven in 2022.展开更多
The middle and lower reaches of the Yangtze River in eastern China during summer 2020 suffered the strongest mei-yu since 1961.In this work,we comprehensively analyzed the mechanism of the extreme mei-yu season in 202...The middle and lower reaches of the Yangtze River in eastern China during summer 2020 suffered the strongest mei-yu since 1961.In this work,we comprehensively analyzed the mechanism of the extreme mei-yu season in 2020,with focuses on the combined effects of the Madden-Julian Oscillation(MJO)and the cooperative influence of the Pacific and Indian Oceans in 2020 and from a historical perspective.The prediction and predictability of the extreme mei-yu are further investigated by assessing the performances of the climate model operational predictions and simulations.It is noted that persistent MJO phases 1−2 during June−July 2020 played a crucial role for the extreme mei-yu by strengthening the western Pacific subtropical high.Both the development of La Niña conditions and sea surface temperature(SST)warming in the tropical Indian Ocean exerted important influences on the long-lived MJO phases 1−2 by slowing down the eastward propagation of the MJO and activating convection related to the MJO over the tropical Indian Ocean.The spatial distribution of the 2020 mei-yu can be qualitatively captured in model real-time forecasts with a one-month lead.This can be attributed to the contributions of both the tropical Indian Ocean warming and La Niña development.Nevertheless,the mei-yu rainfall amounts are seriously underestimated.Model simulations forced with observed SST suggest that internal processes of the atmosphere play a more important role than boundary forcing(e.g.,SST)in the variability of mei-yu anomaly,implying a challenge in quantitatively predicting an extreme mei-yu season,like the one in 2020.展开更多
Thermohaline features, spatial extensions, and depths of the antarctic circumpolar deep water, the antarctic bottom water, and the upper layer water near the Prydz Bay （ including the Prydz Bay s.mmer surface water, ...Thermohaline features, spatial extensions, and depths of the antarctic circumpolar deep water, the antarctic bottom water, and the upper layer water near the Prydz Bay （ including the Prydz Bay s.mmer surface water, the antarctic winter water, and the Prydz Bay shelf water ） are analyzed and studied by use of the full depth CTD data obtained in the Southern Ocean near the Prydz Bay during the 1998/1999 austral summer. The northward extension of the shelf water, the thickness of the temperature inversion layer, the minima in the vertical temperature profile and the vertical temperature gradient are interpreted. On the basis of analysis of gravitational potential field, the geostrophic current and the geostrophic volume transport are calculated to determine the location of the strongest current in the zonal circulation near the Prydz Bay and to find the spatial variability of the volume transport in the64° -66.5°S zone. In addition, the central location, the frontal strength, the vertical depth and thickness of the continental water boundary （CWB） are estimated from the CTD data to expound the spatial variability of CWB in the study area （64° -66.5°S, 70° -75°E）.展开更多
The extreme floods in the Middle/Lower Yangtze River Valley(MLYRV)during June−July 2020 caused more than 170 billion Chinese Yuan direct economic losses.Here,we examine the key features related to this extreme event a...The extreme floods in the Middle/Lower Yangtze River Valley(MLYRV)during June−July 2020 caused more than 170 billion Chinese Yuan direct economic losses.Here,we examine the key features related to this extreme event and explore relative contributions of SST anomalies in different tropical oceans.Our results reveal that the extreme floods over the MLYRV were tightly related to a strong anomalous anticyclone persisting over the western North Pacific,which brought tropical warm moisture northward that converged over the MLYRV.In addition,despite the absence of a strong El Niño in 2019/2020 winter,the mean SST anomaly in the tropical Indian Ocean during June−July 2020 reached its highest value over the last 40 years,and 43%(57%)of it is attributed to the multi-decadal warming trend(interannual variability).Based on the NUIST CFS1.0 model that successfully predicted the wet conditions over the MLYRV in summer 2020 initiated from 1 March 2020(albeit the magnitude of the predicted precipitation was only about one-seventh of the observed),sensitivity experiment results suggest that the warm SST condition in the Indian Ocean played a dominant role in generating the extreme floods,compared to the contributions of SST anomalies in the Maritime Continent,central and eastern equatorial Pacific,and North Atlantic.Furthermore,both the multi-decadal warming trend and the interannual variability of the Indian Ocean SSTs had positive impacts on the extreme floods.Our results imply that the strong multi-decadal warming trend in the Indian Ocean needs to be taken into consideration for the prediction/projection of summer extreme floods over the MLYRV in the future.展开更多
Atmospheric aerosol samples were collected from July to September 2008 onboard a round-trip cruise over the Eastern China Sea, Japan Sea, Western North Pacific Ocean, and the Arctic Ocean （31.1°N-85.18°N, 1...Atmospheric aerosol samples were collected from July to September 2008 onboard a round-trip cruise over the Eastern China Sea, Japan Sea, Western North Pacific Ocean, and the Arctic Ocean （31.1°N-85.18°N, 122.48°E-146.18°W）. Total phosphorus （TP） and total inorganic phosphorus （TIP） were analyzed. The organic phosphorus （OP） was calculated by subtracting TIP from TP. Average concentrations of TP in the East Asia, Western North Pacific and Arctic Ocean were 7.90±6.45, 6.87±6.66 and 7.13±6.76 ng.m^3, while TIP levels were 6.67±5.02, 6.07±6.58, and 6.23±5.96 along the three regions. TP and TIP levels varied considerably both spatially and temporally over the study extent. TIP was found to be the dominant species in most samples, accounting for 86.6% of TP on average. OP was also a significant fraction of TP due to the primary biogenic aerosol （PBA） contribution. The phosphorus in the atmospheric aerosol over the Arctic Ocean had a higher concentration than previous model simulations. Source apportionment analysis indicates that dust is an important phosphorus source which can be globally transported, and thus dust aerosol may be an important nutrient source in some remote regions.展开更多
The pitfalls of applying the commonly used definition of available gravitational potential energy （AGPE） to the world oceans are re-examined. It is proposed that such definition should apply to the meso-scale proble...The pitfalls of applying the commonly used definition of available gravitational potential energy （AGPE） to the world oceans are re-examined. It is proposed that such definition should apply to the meso-scale problems in the oceans, not the global scale. Based on WOA98 climatological data, the meso-scale AGPE in the world oceans is estimated. Unlike previous results by Oort et al. , the meso-scale AGPE is large wherever there is a strong horizontal density gradient. The distribution of meso-scale AGPE reveals the close connection between the baroclinic instability and the release of gravitational potential energy stored within the scale of Rossby deformation radius.展开更多
文摘The Arctic and Antarctica are important components of the Earth system,and the snow and ice over the polar regions make the interactions between the spheres there extremely sensitive to climate change,with an amplifying effect on climate warming.Polar regions are the forefront of global climate and ecosystem changes.More than half of the identified climate tipping elements in our planet occur in the polar regions,with the losses of Arctic sea ice,Greenland ice sheet,permafrost,and western Antarctic ice sheet,being considered as tipping elements with global impacts that have already occurred(McKay et al.,2022).These changes in the polar regions affect the heat and material transfer,water and carbon cycles,as well as biological diversity at a global scale,closely related to global sustainable development.Therefore,polar regions are also considered the limiting factors in achieving the United Nations Sustainable Development Goals(Li et al.,2025).
基金supported the National Natural Science Foundation of China(Grant nos.4227624,42376239 and 42476253)。
文摘Because of their effect on climate,carbon dioxide(CO_(2)),methane(CH_(4)),nitrous oxide(N_(2)O),and dimethylsulfide(DMS)are collectively designated as climate-relevant gases(CRGs).CO_(2),CH_(4),and N_(2)O are greenhouse gases contributing to global warming(positive climate feedback).Conversely,DMS is involved in the generation of cloud condensation nuclei,thus in the formation of clouds that cool the boundary layer by reflecting incoming solar radiation(negative climate feedback).Despite their scarcity,field observations and model results have demonstrated the essential role of polar oceans in the budget of CRGs.For example,the Southern Ocean represents a substantial CO_(2)sink but a source of N_(2)O and DMS,thereby exerting variable feedback on climate change.Unfortunately,because of the severe environmental conditions at polar latitudes,substantial knowledge gaps remain,for example on the mechanisms underlying CRGs formation or on the strength and distribution of their sources and sinks in the Southern and Arctic Oceans.Here,we review the most recent research results on the distribution,production-loss processes,and abundance variations of CRGs in the polar oceans.We list the remaining knowledge gaps and propose future directions of research on CRGs in the polar oceans,as a useful reference for future studies.
基金The Fund of Laoshan Laboratory under contract No.LSKJ202202700the Basic Scientific Fund for National Public Research Institutes of China under contract No.2024Q02+1 种基金the National Natural Science Foundation of China under contract Nos 42076023 and 42430402the Global Change and Air-Sea InteractionⅡProject under contract No.GASI-01-ATP-STwin.
文摘The Indonesian Throughflow(ITF)plays important roles in global ocean circulation and climate systems.Previous studies suggested the ITF interannual variability is driven by both the El Niño-Southern Oscillation(ENSO)and the Indian Ocean Dipole(IOD)events.The detailed processes of ENSO and/or IOD induced anomalies impacting on the ITF,however,are still not clear.In this study,this issue is investigated through causal relation,statistical,and dynamical analyses based on satellite observation.The results show that the driven mechanisms of ENSO on the ITF include two aspects.Firstly,the ENSO related wind field anomalies driven anomalous cyclonic ocean circulation in the western Pacific,and off equatorial upwelling Rossby waves propagating westward to arrive at the western boundary of the Pacific,both tend to induce negative sea surface height anomalies(SSHA)in the western Pacific,favoring ITF reduction since the develop of the El Niño through the following year.Secondly,the ENSO events modulate equatorial Indian Ocean zonal winds through Walker Circulation,which in turn trigger eastward propagating upwelling Kelvin waves and westward propagating downwelling Rossby waves.The Rossby waves are reflected into downwelling Kelvin waves,which then propagate eastward along the equator and the Sumatra-Java coast in the Indian Ocean.As a result,the wave dynamics tend to generate negative(positive)SSHA in the eastern Indian Ocean,and thus enhance(reduce)the ITF transport with time lag of 0-6 months(9-12 months),respectively.Under the IOD condition,the wave dynamics also tend to enhance the ITF in the positive IOD year,and reduce the ITF in the following year.
基金This study was supported by the project of the National Natural Science Foundation of China"Response of inter-decadal variability of South China Sea summer monsoon to the whole globe variability”under contract number 9021l010“Interannual to interdecadal variability in circulation in the tropical Pa-cific Ocean”under contract number 40136010.
文摘The annual, interannual and inter-decadal variability of convection intensity of South China Sea (SCS) summer monsoon and air-sea temperature difference in the tropical ocean is analyzed, and their relationship is discussed using two data sets of 48-a SODA (simple ocean data assimilation) and NCEP/NCAR. Analyses show that in wintertime Indian Ocean (WIO), springtime central tropical Pacific (SCTP) and summertime South China Sea-West Pacific (SSCSWP), air-sea temperature difference is significantly associated with the convection intensity of South China Sea summer monsoon. Correlation of the inter-decadal time scale (above 10 a) is higher and more stable. There is inter-decadal variability of correlation in scales less than 10 a and it is related with the air-sea temperature difference itself for corresponding waters. The inter-decadal variability of the convection intensity during the South China Sea summer monsoon is closely related to the inter-decadal variability of the general circulation of the atmosphere. Since the late period of the 1970s, in the lower troposphere, the cross-equatorial flow from the Southern Hemisphere has intensified. At the upper troposphere layer, the South Asian high and cross-equatorial flow from the Northern Hemisphere has intensified at the same time. Then the monsoon cell has also strengthened and resulted in the reinforcing of the convection of South China Sea summer monsoon.
文摘An ideal and simple formulation is successfully derived that well represents a quasi-linear relationship found between the domain-averaged water vapor, Q （ram）, and temperature, T （K）, fields for the three tropical oceans （i.e., the Pacific, Atlantic and Indian Oceans） based on eleven GEOS-3 [Goddard Earth Observing System （EOS） Version-3] global re-analysis monthly products. A Q - T distribution analysis is also performed for the tropical and extra-tropical regions based on in-situ sounding data and numerical simulations [GEOS-3 and the Goddard Cumulus Ensemble （GCE） model]. A similar positively correlated Q - T distribution is found over the entire oceanic and tropical regions; however, Q increases faster with T for the former region. It is suspected that the tropical oceans may possess a moister boundary layer than the Tropics. The oceanic regime falls within the lower bound of the tropical regime embedded in a global, curvilinear Q - T relationship. A positive correlation is also found between T and sea surface temperature （SST）; however, for one degree of increase in T, SST is found to increase 1.1 degrees for a warmer ocean, which is slightly less than an increase of 1.25 degrees for a colder ocean. This seemingly indicates that more （less） heat is needed for an open ocean to maintain an air mass above it with a same degree of temperature rise during a colder （warmer） season [or in a colder （warmer） region]. Q and SST are also found to be positively correlated. Relative humidity （RH） exhibits similar behaviors for oceanic and tropical regions. RH increases with increasing SST and T over oceans, while it increases with increasing T in the Tropics. RH, however, decreases with increasing temperature in the extratropics. It is suspected that the tropical and oceanic regions may possess a moister local boundary layer than the extratropics so that a faster moisture increase than a saturated moisture increase is favored for the former regions. T, Q, saturated water vapor, RH, and SST are also examined with regard to the warm and cold ＂seasons＂ over individual oceans. The Indian Ocean warm season dominates in each of the five quantities, while the Atlantic Ocean cold season has the lowest values in most categories. The higher values for the Indian Ocean may be due to its relatively high percentage of tropical coverage compared to the other two oceans. However, Q is found to increase faster for colder months from individual oceans, which differs from the general finding in the global Q - T relationship that Q increases slower for a colder climate. The modified relationship may be attributed to a possible seasonal （warm and cold） variability in boundary layer depth over oceans, or to the small sample size used in each individual oceanic group.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB 41000000)the National Natural Science Foundation of China(Nos.42273041,41830214)the Preresearch Project on Civil Aerospace Technologies of CNSA(No.D020101)。
文摘As one of the prominent landforms in the Zhurong landing region,mesas are geological features with flat tops and steep marginal cliffs.The mesas are widely distributed along the dichotomy boundary.There are various interpreted origins proposed for the mesas,such as the erosion of sedimentary layers,tuyas eruptions,or surface collapse due to the catastrophic release of groundwater.We investigate the detailed morphological characteristics of the mesas on the Late Hesperian Lowland unit within the Utopia Planitia.We observe morphological evidence for both the ice-bearing interior mesas and the sedimentary origin,including(1)small pits on the crater wall and mesa cliff formed by the release of volatiles like ice;(2)lobate flows at the base of mesas formed by the melting of subsurface ice;(3)layered mesas indicating sedimentary origin;(4)grooves on the top surface of mesas formed by the volumetric compaction of sedimentary deposits.The results indicate that the mesas in the study area are formed by the erosion of sedimentary layers and representative of the Noachian oceanic sediments.We propose an evolutionary model for the mesas.This study will provide some insights into future research of ancient ocean hypothesis of Mars and interesting targets for the exploration of the Zhurong rover.
基金Supported by the National Basic Research Program of China(973 Program)(No.2012CB956001)the CMA(No.GYHY201306018)+2 种基金the Chinese Academy of Sciences(CAS)(No.XDA11010301)the National Natural Science Foundation of China(Nos.41176019,41421005,U1406401)the State Oceanic Administration(SOA)(No.GASI-03-01-01-05)
文摘A set of absolute geostrophic current(AGC) data for the period January 2004 to December 2012 are calculated using the P-vector method based on monthly gridded Argo profi les in the world tropical oceans. The AGCs agree well with altimeter geostrophic currents, Ocean Surface Current Analysis-Real time currents, and moored current-meter measurements at 10-m depth, based on which the classical Sverdrup circulation theory is evaluated. Calculations have shown that errors of wind stress calculation, AGC transport, and depth ranges of vertical integration cannot explain non-Sverdrup transport, which is mainly in the subtropical western ocean basins and equatorial currents near the Equator in each ocean basin(except the North Indian Ocean, where the circulation is dominated by monsoons). The identifi ed nonSverdrup transport is thereby robust and attributed to the joint effect of baroclinicity and relief of the bottom(JEBAR) and mesoscale eddy nonlinearity.
文摘The exchange of surface freshwater, heat and moisture fluxes across the air-sea interface strongly influences the oceanic circulation and its variability at all time scales. The goal of this paper is to estimate and examine surface freshwater flux at monthly scale exclusively from the Tropical Rainfall Measuring Mission (TRMM) measurements over the tropical oceans for the period of 1998 - 2010. The monthly mean fields of TRMM Microwave Imager (TMI) sea surface temperature (SST), wind speed (WS), and total precipitable water (W) are used to estimate the surface evaporation utilizing the bulk aerodynamics parameterization formula. The merged TRMM Multisatellite Precipitation Analysis (TMPA)-3B43 product is combined with the estimated evaporation to compute the surface freshwater flux. A preliminary comparison of the satellite derived evaporation, precipitation and freshwater flux has been carried out with the Hamburg Ocean Atmosphere Parameters and Fluxes (HOAPS-3) datasets. Also, the estimated evaporation and TMPA-3B43 precipitation are validated with in-situ observations from the moored buoys in the different oceans. The results suggest that the TRMM has great potential to estimate surface freshwater flux for climatological and oceanic hydrological applications.
文摘AWRITER once comparedSino-foreign cultural ex- changes to a lengthybridge across the oceans of theworld.The Beijing CPAA Cultur- al Entertainment Company,esta- blished in the spring of this year,undoubtedly comes to many peo- ple’s minds when contemplatingthis remark.The Beijing CPAA Cultural En- tertainment Company is a subsidi- ary of the China Performing ArtsAgency,directly under the Ministryof Culture.It is a self-managed statefirm specializing in international ex-
文摘(Seventy-third session,Item 78(a)of the provisional agenda,Oceans and the law of the sea,5 September 2018)Summary The present report,which covers the period from 1 September 2017 to 31 August 2018,is submitted pursuant to paragraph 366 of General Assembly resolution 72/73,in which the Assembly requested the Secretary-General to prepare a report on developments and issues relating to ocean affairs and the law of the sea,including the implementation of that resolution,for consideration at its seventy-third session.
基金support has been provided by the Spanish project CGL2012-34618(Ministerio de Economía y Competitividad).
文摘In the Galicia Region of the NW Iberian Massif several allochthonous complexes(Cabo Ortegal,Órdenes and Malpica-Tui)contain a rootless Variscan suture that can be traced along the belt,from Iberia to the Bohemian Massif in Central Europe.Within these allochthonous complexes are several ophiolite zones bounded by two different continental terranes.There exist in NW Iberia two different ophiolite groups with different chemical compositions,isotopic signatures and structural positions.The Bazar and Vila de Cruces ophiolites,characterized by c.500 Ma protolith ages,represent the Lower Group,whereas the Careón,Purrido and Moeche ophiolites containing 395 Ma maficultramafic sequences represent the Upper Group.This younger group constitutes the most widespread ophiolites in the Variscan Belt.A thick serpentinite mélange(Somozas Mélange)occurring at the base of the Cabo Ortegal Complex also belongs to the ophiolite zones of the Variscan suture.In this paper we describe the Galician ophiolites of the Variscan suture and discuss their tectonic setting of formation.We interpret the generation of the Galician ophiolites within the geodynamic and paleogeographic evolution of the Rheic Ocean and the Pangea supercontinent.
基金This work evolved from UNESCO-IUGS IGCP#592 project“Continental construction in Central Asia”(2011-2016)is currently supported by the Ministry of Education and Science of the Russian Federation,grant#14.Y26.31.0018Additional support came from the Russian Foundation for Basic Research(grant#16-05-00313)and Scientific Projects of IGM SB RAS no.0330-2016-0003 and 0330-2016-0018。
文摘Pacific-type orogens(fold belts)hosting accretionary complexes are places keeping records of the evolution of paleo-oceans,and formation and transformation of continental crust at their active convergent margins.Pacific-type orogeny induces destruction of crustal materials,their subduction to the deep mantle,generation of hydrouscarbonated plumes in the mantle transition zone(MTZ)and its related intra-plate magmatism.We propose a new approach for linking paleo-oceans,active margins and intra-plate magmatism in central and eastern Asia.The approach“stands”on three“whales”:the model of Ocean Plate Stratigraphy(OPS),the parameters of Pacific-type convergent margins and a model of hydrous-carbonated plumes.The OPS model evolved from extensive studies of accretionary complexes in the western Pacific,in particular,in Japan;it allows differentiating oceanic plates of one paleoocean and evaluating their sizes and ages.An important issue for reconstructing the history of paleo-oceans is to estimate major parameters of the Pacific-type convergent margins:accreting vs.eroding,geometrical length,and life time.For the eroding margins we must define major periods of tectonic erosion and transportation of oceanic and continental materials to the deep mantle and evaluate a possibility of their accumulation in the MTZ.All this would allow us to develop a holistic model linking the evolution of paleooceans,the accretion and erosion of oceanic and continental crust materials at Pacific-type convergent margins,mantle metasomatism and intra-plate magmatism.
文摘A year after finding a job in a construction com- pany in central China＇s Henan Province, Wang Liang was transferred to a coastal village in Ghana. Expecting to be impressed by the African country＇s natural attractions, Wang, an enthusiastic foodie, was actually overwhelmed by the abundance of local seafood.
基金supported by the National Natural Science Foundation of China (Grant Nos. 42122046 and 42076202)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDB42040402)+4 种基金sponsored by the US National Science Foundationsupported by NASA Awards 80NSSC17K0565 and 80NSSC22K0046by the Regional and Global Model Analysis (RGMA) component of the Earth and Environmental System Modeling Program of the U.S. Department of Energy’s Office of Biological & Environmental Research (BER) via National Science Foundation IA 1947282supported by NOAA (Grant No. NA19NES4320002 to CISESS-MD at the University of Maryland)supported by the Young Talent Support Project of Guangzhou Association for Science and Technology。
文摘Changes in ocean heat content(OHC), salinity, and stratification provide critical indicators for changes in Earth’s energy and water cycles. These cycles have been profoundly altered due to the emission of greenhouse gasses and other anthropogenic substances by human activities, driving pervasive changes in Earth’s climate system. In 2022, the world’s oceans, as given by OHC, were again the hottest in the historical record and exceeded the previous 2021 record maximum.According to IAP/CAS data, the 0–2000 m OHC in 2022 exceeded that of 2021 by 10.9 ± 8.3 ZJ(1 Zetta Joules = 1021Joules);and according to NCEI/NOAA data, by 9.1 ± 8.7 ZJ. Among seven regions, four basins(the North Pacific, North Atlantic, the Mediterranean Sea, and southern oceans) recorded their highest OHC since the 1950s. The salinity-contrast index, a quantification of the “salty gets saltier–fresh gets fresher” pattern, also reached its highest level on record in 2022,implying continued amplification of the global hydrological cycle. Regional OHC and salinity changes in 2022 were dominated by a strong La Ni?a event. Global upper-ocean stratification continued its increasing trend and was among the top seven in 2022.
基金This work was jointly supported by the National Key Research and Development Plan“Major Natural Disaster Monitoring,Warning and Prevention”(2017YFC1502301)the Natural Science Foundation of Shanghai(21ZR1457600)+1 种基金the National Natural Science Foundation of China under Grant No.41790471 and 41775047China Three Gorges Corporation(Grant No.0704181).
文摘The middle and lower reaches of the Yangtze River in eastern China during summer 2020 suffered the strongest mei-yu since 1961.In this work,we comprehensively analyzed the mechanism of the extreme mei-yu season in 2020,with focuses on the combined effects of the Madden-Julian Oscillation(MJO)and the cooperative influence of the Pacific and Indian Oceans in 2020 and from a historical perspective.The prediction and predictability of the extreme mei-yu are further investigated by assessing the performances of the climate model operational predictions and simulations.It is noted that persistent MJO phases 1−2 during June−July 2020 played a crucial role for the extreme mei-yu by strengthening the western Pacific subtropical high.Both the development of La Niña conditions and sea surface temperature(SST)warming in the tropical Indian Ocean exerted important influences on the long-lived MJO phases 1−2 by slowing down the eastward propagation of the MJO and activating convection related to the MJO over the tropical Indian Ocean.The spatial distribution of the 2020 mei-yu can be qualitatively captured in model real-time forecasts with a one-month lead.This can be attributed to the contributions of both the tropical Indian Ocean warming and La Niña development.Nevertheless,the mei-yu rainfall amounts are seriously underestimated.Model simulations forced with observed SST suggest that internal processes of the atmosphere play a more important role than boundary forcing(e.g.,SST)in the variability of mei-yu anomaly,implying a challenge in quantitatively predicting an extreme mei-yu season,like the one in 2020.
基金This study was jointly supported by the National National Science Foundation of China under contract Nos 40376009,40231013 and 49836010the Ministry of Science and Technology of China under contact Nos 2003DIB4J135,2005DIB3J114 and 2006BAC06B02.
文摘Thermohaline features, spatial extensions, and depths of the antarctic circumpolar deep water, the antarctic bottom water, and the upper layer water near the Prydz Bay （ including the Prydz Bay s.mmer surface water, the antarctic winter water, and the Prydz Bay shelf water ） are analyzed and studied by use of the full depth CTD data obtained in the Southern Ocean near the Prydz Bay during the 1998/1999 austral summer. The northward extension of the shelf water, the thickness of the temperature inversion layer, the minima in the vertical temperature profile and the vertical temperature gradient are interpreted. On the basis of analysis of gravitational potential field, the geostrophic current and the geostrophic volume transport are calculated to determine the location of the strongest current in the zonal circulation near the Prydz Bay and to find the spatial variability of the volume transport in the64° -66.5°S zone. In addition, the central location, the frontal strength, the vertical depth and thickness of the continental water boundary （CWB） are estimated from the CTD data to expound the spatial variability of CWB in the study area （64° -66.5°S, 70° -75°E）.
基金This work is supported by National Natural Science Foundation of China(Grant No.42030605 and 42088101)National Key R&D Program of China(Grant No.2020YFA0608004).
文摘The extreme floods in the Middle/Lower Yangtze River Valley(MLYRV)during June−July 2020 caused more than 170 billion Chinese Yuan direct economic losses.Here,we examine the key features related to this extreme event and explore relative contributions of SST anomalies in different tropical oceans.Our results reveal that the extreme floods over the MLYRV were tightly related to a strong anomalous anticyclone persisting over the western North Pacific,which brought tropical warm moisture northward that converged over the MLYRV.In addition,despite the absence of a strong El Niño in 2019/2020 winter,the mean SST anomaly in the tropical Indian Ocean during June−July 2020 reached its highest value over the last 40 years,and 43%(57%)of it is attributed to the multi-decadal warming trend(interannual variability).Based on the NUIST CFS1.0 model that successfully predicted the wet conditions over the MLYRV in summer 2020 initiated from 1 March 2020(albeit the magnitude of the predicted precipitation was only about one-seventh of the observed),sensitivity experiment results suggest that the warm SST condition in the Indian Ocean played a dominant role in generating the extreme floods,compared to the contributions of SST anomalies in the Maritime Continent,central and eastern equatorial Pacific,and North Atlantic.Furthermore,both the multi-decadal warming trend and the interannual variability of the Indian Ocean SSTs had positive impacts on the extreme floods.Our results imply that the strong multi-decadal warming trend in the Indian Ocean needs to be taken into consideration for the prediction/projection of summer extreme floods over the MLYRV in the future.
基金supported by grants from the National Natural Science Foundation of China (Grant nos. 41176170 and 41025020)the Chinese Polar Environment Comprehensive Investigation & Assessment Programs (Grant no. CHINARE2011-2015)
文摘Atmospheric aerosol samples were collected from July to September 2008 onboard a round-trip cruise over the Eastern China Sea, Japan Sea, Western North Pacific Ocean, and the Arctic Ocean （31.1°N-85.18°N, 122.48°E-146.18°W）. Total phosphorus （TP） and total inorganic phosphorus （TIP） were analyzed. The organic phosphorus （OP） was calculated by subtracting TIP from TP. Average concentrations of TP in the East Asia, Western North Pacific and Arctic Ocean were 7.90±6.45, 6.87±6.66 and 7.13±6.76 ng.m^3, while TIP levels were 6.67±5.02, 6.07±6.58, and 6.23±5.96 along the three regions. TP and TIP levels varied considerably both spatially and temporally over the study extent. TIP was found to be the dominant species in most samples, accounting for 86.6% of TP on average. OP was also a significant fraction of TP due to the primary biogenic aerosol （PBA） contribution. The phosphorus in the atmospheric aerosol over the Arctic Ocean had a higher concentration than previous model simulations. Source apportionment analysis indicates that dust is an important phosphorus source which can be globally transported, and thus dust aerosol may be an important nutrient source in some remote regions.
基金the National Naturale Science Foundation of China under contract No. 40476010 the Research Fund for the Doctoral Program of Higher Education of China under contract No. 20030423011
文摘The pitfalls of applying the commonly used definition of available gravitational potential energy （AGPE） to the world oceans are re-examined. It is proposed that such definition should apply to the meso-scale problems in the oceans, not the global scale. Based on WOA98 climatological data, the meso-scale AGPE in the world oceans is estimated. Unlike previous results by Oort et al. , the meso-scale AGPE is large wherever there is a strong horizontal density gradient. The distribution of meso-scale AGPE reveals the close connection between the baroclinic instability and the release of gravitational potential energy stored within the scale of Rossby deformation radius.
