On the relationship between convection intensity of South China Sea summer monsoon and air-sea temperature difference in the tropical oceans

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.

Absolute geostrophic currents in global tropical oceans

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.

A Note on the Relationship Between Temperature and Water Vapor over Oceans, Including Sea Surface Temperature Effects

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.

Surface Freshwater Flux Estimation Using TRMM Measurements Over the Tropical Oceans

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.

A Bridge Across the Oceans——An Interview with the Beijing CPAA Cultural Entertainment Company

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-

Oceans and the Law of the Sea Report of the Secretary-General

(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.

Oceans of Opportunity

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.

The Extreme Mei-yu Season in 2020:Role of the Madden-Julian Oscillation and the Cooperative Influence of the Pacific and Indian Oceans

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.

Features of physical oceanography in the oceans near the Prydz Bay during the 1998/1999 austral summer

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）.

Toward Understanding the Extreme Floods over Yangtze River Valley in June−July 2020:Role of Tropical Oceans

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.

Another Year of Record Heat for the Oceans

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.

Phosphorus in the aerosols over oceans transported offshore from China to the Arctic Ocean: Speciation, spatial distribution, and potential sources

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.

Meso-scale available gravitational potential energy in the world oceans

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.

Extracellular enzymatic activities of cold-adapted bacteria from polar oceans and effect of temperature and salinity on cell growth

The potential of 324 bacteria isolated from different habitats in polar oceans to produce a variety of extracellular enzymatic activities at low temperature was investigated. By plate assay, lipase, protease, amylase, gelatinase, agarase, chitinase or cellulase were detected. Lipases were generally present by bacteria living in polar oceans. Protease-producing bacteria held the second highest proportion in culturable isolates. Strains producing amylase kept a relative stable proportion of around 30% in different polar marine habitats. All 50 Arctic sea-ice bacteria producing proteases were cold-adapted strains, however, only 20% were psychrophilic. 98% of them could grow at 3% NaCl, and 56% could grow without NaCl. On the other hand, 98% of these sea-ice bacteria produced extracellular proteases with optimum temperature at or higher than 35℃, well above the upper temperature limit of cell growth. Extracellular enzymes including amylase, agarase, cellulase and lipase released by bacteria from seawater or sediment in polar oceans, most expressed maximum activities between 25 and 35℃. Among extracellular enzymes released by bacterial strain BSw20308, protease expressed maximum activity at 40℃, higher than 35℃ of polysaccharide hydrolases and 25℃ of lipase.

The adjoint-based Two Oceans One Sea State Estimate(TOOSSE)

An eddy-resolving four-dimensional variational(adjoint)data assimilation and state estimate was constructed for the low-to mid-latitude Pacifi c,Indian Oceans,and South China Sea based on the framework of“Estimating the Circulation and Climate of the Oceans(ECCO)”.It is named as the Two Oceans One Sea State Estimate(TOOSSE).It fi ts a model to a number of modern observations of 2015-2016,including the Argo fl oat temperature and salinity,satellite altimetric sea surface anomalies,by adjusting initial temperature and salinity,sea surface boundary conditions,and background diapycnal diff usivities.In total,~50%of the original model-data misfi ts have been eliminated,and the estimated state agreed well with a variety of independent observations at meso-to large scales,and on the intra-seasonal to interannual timescales.Mesoscale variability is systematically strengthened in TOOSSE and closer to observations than that without data assimilation,which is especially evidenced by the improved simulation of the mesoscale tropical instability waves(TIWs).Adjustments to ocean surface forcing parameters exhibit both large and frontal/mesoscale structures,and the magnitude reach 20%-100%of the fi rst guesses;the adjustments to diapycnal diff usivity exhibit an obvious elevation(decrement)in(below)the thermocline in the equatorial band.The results indicate that TOOSSE represents a dynamically and thermodynamically consistent ocean state estimate of the 2015-2016 Indo-Pacifi c Ocean,and can be widely utilized for regional process studies.

Turbulence and Fossil Turbulence in Oceans and Lakes

Turbulence is defined as an eddy-like state of fluid motion where the inertial-vortex forces of the eddies are larger than any of the other forces that tend to damp the eddies out. Energy cascades of irrotational flows from large scales to small are non-turbulent, even if they supply energy to turbulence. Turbulent flows are rotational and cascade from small scales to large, with feedback. Viscous forces limit the smallest turbulent eddy size to the Kolmogorov scale. In stratified fluids, buoyancy forces limit large vertical overturns to the Ozmidov scale and convert the largest turbulent eddies into a unique class of saturated, non-propagating, internal waves, termed fossil-vorticity-turbulence. These waves have the same energy but different properties and spectral forms than the original turbulence patch. The Gibson (1980, 1986) theory of fossil turbulence applies universal similarity theories of turbulence and turbulent mixing to the vertical evolution of an isolated patch of turbulence in a stratified fluid as its growth is constrained and fossilized by buoyancy forces. Quantitative hydrodynamic-phase-diagrams (HPDs) from the theory are used to classify microstructure patches according to their hydrodynamic states. When analyzed in HPD space, previously published oceanic datasets showed their dominant microstructure patches are fossilized at large scales in all layers. Laboratory and field measurements suggested phytoplankton species with different swimming abilities adjust their growth strategies by pattern recognition of turbulence-fossil-turbulence dissipation and persistence times that predict survival-relevant surface layer sea changes. New data collected near a Honolulu waste-water outfall showed the small-to-large evolution of oceanic turbulence microstructure from active to fossil states, and revealed the ability of fossil-density-turbulence patches to absorb, and vertically radiate, internal wave energy, information, and enhanced turbulent-mixing-rates toward the sea surface so that the submerged waste-field could be detected from a space satellite (Bondur and Filatov, 2003).

Nitrous oxide research progress in polar and sub-polar oceans

N2O gas depletes ozone and has a powerful greenhouse effect.Oceans are among the most important N2O sources and have been the subject of extensive studies.Polar oceans are important regions for deep water formation and global-scale thermohaline circulation.Therefore,these water bodies play an important role in the N2O budget,however,these regions were not well studied.This review of previously published studies and data on polar oceans,including both the Arctic Ocean and Southern Ocean,describes the distribution pattern of N2O and possible regulating mechanism of these distribution patterns and shows that the Arctic Ocean and Southern Ocean both represent source and sink regions,suggesting that the source/sink characteristics of the Arctic and Southern oceans and their strengths need further study.Questions related to N2O circulation in polar oceans were proposed,and future work is suggested.

A Stochastic Study of the Fractional Order Model of Waste Plastic in Oceans

In this paper,a fractional order model based on the management of waste plastic in the ocean(FO-MWPO)is numerically investigated.The mathematical form of the FO-MWPO model is categorized into three components,waste plastic,Marine debris,and recycling.The stochastic numerical solvers using the Levenberg-Marquardt backpropagation neural networks(LMQBP-NNs)have been applied to present the numerical solutions of the FO-MWPO system.The competency of the method is tested by taking three variants of the FO-MWPO model based on the fractional order derivatives.The data ratio is provided for training,testing and authorization is 77%,12%,and 11%respectively.The exactness of LMQBP-NNs is observed by using the comparative performances of the obtained and the Adams-BashforthMoulton method.To verify the competence,validity,capability,exactness,and consistency of LMQBP-NNs,the performances have been obtained using the regression,state transitions,error histograms,correlation and mean square error.

Spatial variability ofδ^(18)O andδ^(2)H in North Pacific and Arctic Oceans surface seawater

This study presents new observations of stable isotopic composition(δ^(18)O,δ^(2)H and deuterium excess)in surface waters of the North Pacific and Arctic Oceans that were collected during the sixth Chinese National Arctic Research Expedition(CHINARE)from mid-summer to early autumn 2014.Seawaterδ^(18)O andδ^(2)H decrease with increasing latitudes from 39°N to 75°N,likely a result of spatial variability in evaporation/precipitation processes.This explanation is further confirmed by comparing theδ^(18)O-δ^(2)H relationship of seawater with that of precipitation.However,effects of freshwater inputs on seawater stable isotopic composition are also identified at 30°N-39°N.Furthermore,we find a non-significant relationship between the isotopic parameters(δ^(2)H andδ^(18)О)and salinity from 73°N northwards in the Arctic Ocean,implying that sea ice melting/formation may have some effect.These results suggest that the isotopic parametersδ^(2)H andδ^(18)Оare useful for tracing marine hydrological processes.