A parameterization scheme of vertical mixing due to inertial internal wave breaking in the ocean general circulation model

Based on the theoretical spectral model of inertial internal wave breaking(fine structure) proposed previously, in which the effects of the horizontal Coriolis frequency component f-tilde on a potential isopycnal are taken into account, a parameterization scheme of vertical mixing in the stably stratified interior below the surface mixed layer in the ocean general circulation model(OGCM) is put forward preliminarily in this paper. Besides turbulence, the impact of sub-mesoscale oceanic processes(including inertial internal wave breaking product) on oceanic interior mixing is emphasized. We suggest that adding the inertial internal wave breaking mixing scheme(F-scheme for short) put forward in this paper to the turbulence mixing scheme of Canuto et al.( T-scheme for short) in the OGCM, except the region from 15°S to 15°N. The numerical results of F-scheme by using WOA09 data and an OGCM(LICOM, LASG/IAP climate system ocean model) over the global ocean are given. A notable improvement in the simulation of salinity and temperature over the global ocean is attained by using T-scheme adding F-scheme, especially in the mid- and high-latitude regions in the simulation of the intermediate water and deep water. We conjecture that the inertial internal wave breaking mixing and inertial forcing of wind might be one of important mechanisms maintaining the ventilation process. The modeling strength of the Atlantic meridional overturning circulation(AMOC) by using T-scheme adding F-scheme may be more reasonable than that by using T-scheme alone, though the physical processes need to be further studied, and the overflow parameterization needs to be incorporated. A shortcoming in F-scheme is that in this paper the error of simulated salinity and temperature by using T-scheme adding F-scheme is larger than that by using T-scheme alone in the subsurface layer.

Spatial structure and seasonal changes of nekton assemblages in the Taiwan Strait

The Taiwan Strait is a transition zone between the East China Sea and the South China Sea with unique hydrology and a geographical environment that creates special marine community features.To analyze the spatial structure and seasonal changes of the nekton assemblages in the Taiwan Strait,seasonal experimental trawl surveys were conducted during 2006–2007.The results showed that there were two assemblages in the area with different sets of species,and the average similarity within each group varies between 39.38% and 74.20%.By using multivariate statistical analysis and analyzing the distribution of dominant species,we found that the structures of the assemblages had obvious seasonal variation.The middle region from the Putian transect to the Xiamen transect could be considered a mixing area for the two assemblages.The analysis of the relationship between species assemblages and environmental factors indicated that temperature was the most important factor affecting the community structure in cold seasons,and 22.5°C and 17°C could be considered dividing lines for spring and winter,respectively.In warm seasons,the most important factor was water depth,but the relationship with depth was not as significant,with a correlation between 0.264 and 0.399.The seasonal changes of nekton assemblages basically reflected the dynamic currents in the Taiwan Strait.The south coastal assemblage extended to nearly the entire area of the Taiwan Strait along with a strong and intense warm current that shrinks in spring and winter when the southward intrusion of the cold Zhejiang-Fujian coastal current becomes stronger.The impact of shortterm and long-term environmental changes,such as extreme weather,global warming and human activity on nekton assemblages,had been recognized but need further research.Our study on nekton assemblages could be used as a baseline for measuring future changes.

China's First Exploration of Chukchi Sea and Its Adjacent Waters in the ArcticA Study on Lead Geochemistry of Atmospheric Aerosol

The Pb concentrations of atmospheric aerosol in the Chukchi Sea of the Arctic vary within the range of 0.167- 0.962 ng/m3, with an average of 0.532 ng/m3. These concentration values are 200 times higher than the natural background values of snow samples there. Calculation of the Pb enrichment factor of aerosol indicates that the ocean- and continent-source lead account for 9.23% and 0.01%, respectively, but industrially released Pb accounts for more than 90% of the atmospheric Pb. The Pb isotopic composition of aerosol has revealed that the sources of lead from industrial lead that causes pollution include mainly the western part of North America, East Europe and the former Soviet Union. The calculation of the total fallout flux of Pb indicates that the mean value of input flux into the Chukchi Sea is 0.02 mgm -2a -1,equivalent to that of southern Pacific but slightly lower than that of northern Indian Sea and southern Atlantic. It is evidenced that the Pb input flux into the Chukchi Sea is far lower than that off the Baltic Sea, the North Sea and the Mediterranean Sea.

Analysis of monthly variability of thermocline in the South China Sea

This study analyzes monthly variability of thermocline and its mechanism in the South China Sea(SCS). The study is based on 51-year(1960–2010) monthly seawater temperature and surface wind stress data from Simple Ocean Data Assimilation(SODA), together with heat flux, precipitation and evaporation data from the National Centers for Environmental Prediction(NCEP), the National Oceanic and Atmospheric Administration(NOAA) and the Woods Hole Oceanographic Institution, respectively. The results reveal that the upper boundary depth(Z_(up)), lower boundary depth(Z _(low)), thickness(?Z) and intensity( T _z) of thermocline in the SCS show remarkable monthly variability. Being averaged for the deep basin of SCS, Z_(up) deepens gradually from May to the following January and then shoals from February to May, while Z low varies little throughout the whole year. Further diagnostics indicates that the monthly variability of Z_(up) is mainly caused by the buoyancy flux and wind stress curl. Using a linear method, the impacts of the buoyancy flux and wind stress curl on Z_(up) can be quantitatively distinguished. The results suggest that Z_(up) tends to deepen about 4.6 m when the buoyancy flux increases by 1×10^(-5) kg/(m?s ~3), while it shoals about 2.5 m when the wind stress curl strengthens by 1×10-^(7) N/m3.

Comparative study of hydrographic conditions for algal bloom formation in the coastal waters of east and west of Hong Kong during 1998

Phytoplankton abundance was found to be positively correlated with seasonal changes of seawater temperature in Port Shelter and Lamma Channel, Hong Kong in 1998. Rising water temperature from around 20°C to 25°C coincided with an increase in phytoplankton abundance at both locations. Heavy rains from June to September reduced salinity from 30 to 20, but the decrease in salinity was not correlated with a decline in phytoplankton abundance. In spring 1998, over 0.6×106 cells dm-3 and 0.1×106 cells dm-3 of the dinoflagellate, Gymnodinium mikimotoi Miyake et Kominami ex Oda occurred in the coastal waters of Port Shelter and Lamma Channel, respectively. High abundance of the dinoflagellate Ceratium furca (Ehr.) Claparede et Lachmann (>1×106 cells dm-3) produced long-lasting blooms in the waters of Port Shelter from September to October in 1998. The abundances of both diatoms and dinoflagellates were significantly lower in the waters of Lamma Channel than those in Port Shelter due to the less frequent blooms in 1998.

A study of response of thermocline in the South China Sea to ENSO events

This paper investigates the response of the thermocline depth(TD) in the South China Sea(SCS) to the El Ni?o-Southern Oscillation(ENSO) events using 51-year(from 1960 to 2010) monthly seawater temperature and surface wind stress data acquired from the Simple Ocean Data Assimilation(SODA), together with heat flux data from the National Centers for Environmental Prediction(NCEP), precipitation data from the National Oceanic and Atmospheric Administration(NOAA) and evaporation data from the Woods Hole Oceanographic Institution(WHOI). It is indicated that the response of the SCS TD to the El Ni?o or La Ni?a events is in opposite phase. On one hand, the spatial-averaged TDs in the SCS(deeper than 200 m) appear as negative and positive anomalies during the mature phase of the El Ni?o and La Ni?a events, respectively. On the other hand, from June of the El Ni?o year to the subsequent April, the spatial patterns of TD in the north and south of 12°N appear as negative and positive anomalies, respectively, but present positive and negative anomalies for the La Ni?a case. However, positive and negative TD anomalies occur almost in the entire SCS in May of the subsequent year of the El Ni?o and La Ni?a events, respectively. It is suggested that the response of the TD in the SCS to the ENSO events is mainly caused by the sea surface buoyancy flux and the wind stress curl.

Research on the Diets Determination for Initial Feeding of Anguilla mormorata Glass Eel

[Objective]To find a suitable food for initial feeding of Anguilla mormorata glass eels.[Method]A pre-weaning feeding experiment was conducted indoor in fiberglass tanks,three different diets,Tubifex,minced octopus flesh and 1∶ 1 mixture (by weight) of Tubifex and minced octopus flesh were introduced.[Result]All three kinds of diets were acceptable to A.mormorata glass eels,and of three diets,the minced octopus flesh could serve as the best food for initial feeding of A.mormorata glass eels,which contributed 93% survival at the termination of the 21-days experiment and provided with relatively fast growth and homogeneous size variation.[Conclusion]The minced octopus flesh can serve as a suitable food to replace Tubifex for the initial feeding of anguilla glass eels.

Study on fish life history traits and variation in the Taiwan Strait and its adjacent waters

Large portions of the world's fishery resources are overexploited. Life history traits of fish species are important indicators to reveal different life history strategies and to indicate population responses to fishing pressures. For this study, empirical data on fishing grounds located in the coastal area between Fujian Coast and Taiwan Island were collected. These areas have experienced severe overfishing in the past 30 years, leading to changes in the structure and function of the fish communities. Fifty-one commercial fish species in this fishing ground were selected to study the life history traits. Using the life history traits, all the species were grouped into five different life history strategies by principle component analysis. More than 60% of the species were categorized in Group 5 that was similar to r-strategists. Twenty-five commercial species were selected for further analysis of changes in life history variables, and to discuss the population responses to exploitation. Results showed that most of the species appeared to become smaller size, shorter life, earlier maturation and faster growing under long-term exploitation. The exploitation rate of each species was also calculated to further discuss the impacts of fishing pressures to fish populations. Four species were found with the severest changes on life history traits indicating some of the species might be more susceptible to exploitation. This study on fish life history traits and their long-term variations under fishing pressures could provide important scientific implications for fishery management and conservation.

Layered zirconium phosphate-supported metalloporphyrin:Synthesis and catalytic application

这份报纸报导为分层的 alpha 锆磷酸盐(伪 - ZrP ) 的准备的一条新线路支持了 metalloporphyrin MnTMPyP。MnTMPyP 用伪 - ZrP 路 B A 被设置进伪 - ZrP (即预先设置的 bultylamine 被一个单层模式在伪 - ZrP 安排) 作为开始的材料。为 homovanillic 酸(HVA ) 的支持的材料的催化活动氧化被调查。结果在催化系统显示出有希望的分层的支持材料的催化剂。

Modeling effective viscosity reduction behaviour of solid suspensions

Under a simple shearing flow,the effective viscosity of solid suspensions can be reduced by controlling the inclusion particle size or the number of inclusion particles in a unit volume.Based on the Stokes equation,the transformation field method is used to model the reduction behaviour of effective viscosity of solid suspensions theoretically by enlarging the particle size at a given high concentration of particles.With a lot of samples of random cubic particles in a unit cell,our statistical results show that at the same higher concentration,the effective viscosity of solid suspensions can be reduced by increasing the particle size or reducing the number of inclusion particles in a unit volume.This work discloses the viscosity reduction mechanism of increasing particle size,which is observed experimentally.

Effects of live rock on removal of dissolved inorganic nitrogen in coral aquaria

Maintaining stable water quality is one of the key processes for recirculating coral aquaculture. Traditional aquarium systems which mainly utilized a nitrification of nitrifying bacteria attached to the surface of massive artificial filter material are difficult to maintain the oligotrophic conditions necessary for coral aquaculture. This study investigated the removal effects of dissolved inorganic nitrogen(ammonia and nitrate) by live rock(LR), a key component in the "Berlin system" coral aquarium. The expression levels of bacterial functional genes, AOA3,amo A and nos Z, were measured on the exterior and interior of LR. The nitrifying and denitrifying bacterial abundance on LR was quantified and the nitrogen nutrient regulatory effects of LR were evaluated. The results demonstrated that LR mainly removed ammonium(NH_4^+) from the water with a mean efficiency of 0.141 mg/(kg·h), while the removal of nitrate(NO_3~–) was not significant. Bacterial diversity analysis showed that ammonia-oxidizing bacteria(AOB) were the most common bacteria on LR, which accounted for 0.5%–1.4% of the total bacterial population, followed by denitrifying bacteria, which accounted for 0.2% of the total population, and the ammonia-oxidizing archaea(AOA) were the least common type(<0.01%). The low abundance of denitrifying bacteria may be responsible for the poor nitrate(NO_3~–) removal of LR. Thus, other biological filtration methods are needed in coral aquaria to control nitrates generated from nitrification or biological metabolism.

First record of genera Rutilaria and Trigonium(Bacillariophyta) and 11 diatom taxa(species and varieties) in South China Sea

Diatom taxa in samples collected from the uppermost 1-cm sediment of the South China Sea(SCS) during cruises in 2000,2001,and 2007 were investigated.Among them,two genera,Rutilaria and Trigonium,and 11 marine taxa(species and varieties) were described for the first time in China.The 11 taxa,Rutilaria radiata,Asterolampra grevillei,Biddulphia turrigera,Cocconeis cyclophora var.decora,Cocconeis ocellata,Dictyoneis marginata,Entogonia davyana,Tryblionella campechiana,Plagiogramma kinkeri,Plagiogramma nankoorense and Trigonium cf.contumax,were mainly extant species,although Rutilaria radiata and Entogonia davyana are fossils.Available data show that these species are mainly present in the eastern and western Pacific Ocean and the Indian Ocean.A large number of taxa newly recorded in this study were previously reported in the Philippines.The presence of these taxa in both locations is likely a result of seawater exchange in the SCS through the Bashi Channel.Taxonomic descriptions,habitats,and distributions of each diatom taxon are provided herein.

Estimation of vertical diffusion coefficient based on a onedimensional temperature diffusion equation with an inverse method

Diapycnal mixing is important in oceanic circulation. An inverse method in which a semi-explicit scheme is applied to discretize the one-dimensional temperature diffusion equation is established to estimate the vertical temperature diffusion coefficient based on the observed temperature profiles. The sensitivity of the inverse model in the idealized and actual conditions is tested in detail. It can be found that this inverse model has high feasibility under multiple situations ensuring the stability of the inverse model, and can be considered as an efficient way to estimate the temperature diffusion coefficient in the weak current regions of the ocean. Here, the hydrographic profiles from Argo floats are used to estimate the temporal and spatial distribution of the vertical mixing in the north central Pacific based on this inverse method. It is further found that the vertical mixing in the upper ocean displays a distinct seasonal variation with the amplitude decreasing with depth, and the vertical mixing over rough topography is stronger than that over smooth topography. It is suggested that the high-resolution profiles from Argo floats and a more reasonable design of the inverse scheme will serve to understand mixing processes.

Chemistry of Aerosols over Chukchi Sea and Bering Sea

The contents of elements in aerosols sampled during the First Chinese Arctic Research Expedition (CHINARE-1) show great differences from one element to another. Na, K, Ca, Mg, Al, F, and Cl are the major components in the aerosols, whose contents are larger than 30 ng/m+3. The chemical elements whose contents vary between {0.1}-30 ng/m+3 are Br, Sr, Cr, Ni, and Zn. The chemical elements whose contents are close to or slightly higher than {0.1} ng/m+3 are Rb, Ba, Zr, Th, and Pb. The contents of As, Sb, W, Mo, Au, La, Ce, Nd, Sm, Eu, Tb, Yb, Lu, Sc, Co, Hf, Ta, and Cd are less than {0.1} ng/m+3. The mass concentration data for the same element, as observed during CHINARE-1, are almost accordant, but much lower than what is observed in the China’s seas or the coasts of China. The enrichment factor and electron microscopic analyses and lead isotope tracing were used to distinguish their sources. Four groups of sources can be classified as follows: anthropogenic: As, Sb, W, F, Mo, Au, Cu, Pb, Cd, V; crustal: La, Ce, Nd, Sm, Eu, Tb, Yb, Lu, Fe, Sc, Cr, Co, Ba, Zr, Hf, Ta, Cs, Mn, Th, U; oceanic:Na, K, Ca, and Mg; and mixing: Rb, Sr, Ca, and Mg.

Electrospray Ionization Mass Spectra of Amino Acid Methyl Ester 5′-Phosphoramidates of 2′,3′-Isopropylideneuridine

Amino acid methyl ester phosphates were synthesized and determined by using positive-ion mode electrospray ionization mass spectrometry(ESIMS) in combination with multistage tandem mass spectrometry. The fragmentation pathways were investigated, and it was observed that most fragment ions contained the phosphoryl group. It was interesting to observe that the fragmentation pathways of the protonated molecule show some differences when compared with those of the sodium ion adduct. The methoxy group of amino acid methyl ester can migrate from the carbonyl group to the phosphoryl group in the sodium ion adduct.

Advances in Application of Environmental-friendly Seaweed Polysaccharide Biomaterials

Seaweed polysaccharides are a type of natural high-molecular active substances extracted and purified from seaweed. They are formed from different monosaccharide units through glucosidic bonds,with the advantages of high viscosity,good gel property,environmental-friendly and low cost. In this review,we focus on the progress of the application of seaweed polysaccharides in the fields including food,medicine,tissue engineering and environment engineering,where seaweed polysaccharides are used as food additives,edible coating materials,drug-release materials,medical dressing,tissue scaffolds and environmental adsorption materials. Introducing special properties,such as targeting,electrical conductivity and thermosensitivity,and designing bionic controllable micro/nanostructures to fabricate and develop multi-functional,intelligent seaweed polysaccharides would be the research hotspot in the future.

Annual variation of sea surface height, dynamic topography and circulation in the South China Sea —— A TOPEX/Poseidon satellite altimetry study

TOPEX/Poseidon satellite altimetry data from 1993 to 1999 were used to study mean annual variation of sea surface height anomaly (SSHA) in the South China Sea (SCS) and to re-produce its climatological monthly surface dynamic topography in conjunction with historical hy-drographic data. The characters and rules of seasonal evolution of the SCS dynamic topography and its upper circulation were then discussed. Analyses indicate that annual variation of the SCS large-scale circulation could be divided into four major phases. In winter (from November to Feb-ruary), the SCS circulation is mainly controlled by double cyclonic gyres with domination of the northern gyre. Other corresponding features include the Kuroshio intrusion from the Luzon Strait and the northeastward off-shelf current in the area northwest off Kalimantan Island. The double gyre structure disassembled in spring (from March to April) when the northern gyre remains cyc-lonic, the southern gyre becomes anticyclonic, and the general circulation pattern shows a dipole. There is no obvious large-scale closed gyre inside the SCS basin in both summer (from May to July) and autumn (from August to October) when the SCS Monsoon Jet dominates the circulation, which flows northeastward across the SCS. Even so, circulation patterns of these two phases di-verse significantly. From May to July, the SCS monsoon jet flows northward near the Vietnam coast and bends eastward along the topography southeast off Hainan Island at about 18N form-ing an anticyclonic turn. It then turns northeastward after crossing the SCS. From August to Octo-ber, however, the monsoon Jet leaves the coast of Vietnam and enters interior of the basin at about 13N, and the general circulation pattern becomes cyclonic. The Kuroshio intrusion was not obvious in spring, summer and autumn. It is suggested from these observations that dynamic ad-justment of the SCS circulation starts right after the peak period of the prevailing monsoon.

Trends of sea level rise in the South China Sea during the 1990s: An altimetry result

Using 7 years of TOPEX/POSEIDON satellite altimetry data, we have identified a general trend of sea level rising in the South China Sea between January 1993 and December 1999. The estimated bulk rising rate of the entire basin is-1 cm/a. The rise of sea level appears to be spatially non-homogeneous, which shows a highest rate of 2.7 cm/a in the deep basin west of Luzon and generally low (even negative) rates over the shallow continental shelves. It is believed that the observed rapid rising of sea level is a regional phenomenon and is mainly caused by warming of the upper layer of the South China Sea, which showed a bulk warming rate of 0.15癈/a in the same period. It is also suggested that the observed rising trend is mainly a decadal signal, which is possibly associated with decadal variation of the Pacific warm pool region.

Coupling and propagating of mesoscale sea level variability between the western Pacific and the South China Sea

The coupling and propagating features of mesoscale sea level variability between the western Pacific (WP) and the South China Sea (SCS) were studied based on time series analyses of satellite altimeter measured, along-track sea surface height anomalies (SSHA) along 21°N and the slope of the northern SCS. The analyses show that mesoscale sea level fluctuations in the WP have rather limited coherent effects on the SCS, and no statistically significant propagation of mesoscale variability through the Luzon Strait was observed except in the 45-day band. Evidence suggests that the 45-day fluctuation is very much likely a character of the Kuroshio originating from its low-latitude beginning. It is also sug- gested that the westward propagating Rossby waves will deform when they encounter the dynamical barrier of the Kuroshio. The Kuroshio will then acts on the SCS in its own way. The SCS is a relatively isolated system in the sense of coupling and propagating of oceanic mesoscale waves.

Responses of the Zhe-Min coastal current adjacent to Pingtan Island to the wintertime monsoon relaxation in 2006 and its mechanism

In conjunction with synchronous remotely sensed winds and sea surface temperature(SST),the spatiotemporal features of the Zhe-Min coastal current(ZMCC),especially responses of the ZMCC adjacent to Pingtan Island(PT) to the wintertime monsoon relaxation in 2006 and corresponding mechanism are investigated based on the field observations.In situ data are acquired from Conductivity-Temperature-Depth(CTD) cruise and Bottom-Mounted Moorings(BMM),which are conducted during a comprehensive survey for the Chinese Offshore Investigation and Assessment Project in winter 2006.It is revealed that the ZMCC is well mixed vertically in winter 2006.The ZMCC(<14°C) recedes during the relaxation of the wintertime monsoon and is accompanied by the enhanced northward shift of the warm,saline Taiwan Strait Mixed Water(TSMW,higher than 14°C and is constituted by the Taiwan Strait Warm Water and the Kuroshio Branch Water).And greatly enhanced southward intrusion of the ZMCC can be detected when the wintertime monsoon restores.Correspondingly,the thermal interface bounded by the ZMCC and the TSMW moves in the northwest/southeast direction,leading to periodic warm/cold reversals of the near-seabed temperature adjacent to the PT.By EOF(Empirical Orthogonal Function) analysis of the large-scale wind fields and wavelet power spectrum analysis of the water level,ocean current and the near-seabed temperature,responses of the ZMCC off the PT to wintertime monsoon relaxation are suggested to be attributed mainly to the southward propagating coastally trapped waves triggered by the impeding atmospheric fronts.As a result,ocean current and near-seabed temperature demonstrate significant quasi-5 d and quasi-10 d subtidal oscillations.By contrast,the onshore/offshore water accumulation resulted from Ekman advection driven by the local winds has minor contributions.