2013 Vol. 32, No. 10

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2013, 32(10): .
2013, 32(10): .
Acta Oceanologica Sinica (AOS) is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.
The long-term trend of the sea surface wind speed and the wave height (wind wave, swell, mixed wave)in global ocean during the last 44 a
ZHENG Chongwei, ZHOU Lin, HUANG Chaofan, SHI Yinglong, LI Jiaxun, LI Jing
2013, 32(10): 1-4. doi: 10.1007/s13131-013-0358-5
Utilizing the 45 a European Centre for Medium-Range Weather Forecasts(ECMWF)reanalysis wave data(ERA-40),the long-term trend of the sea surface wind speed and(wind wave,swell,mixed wave)wave height in the global ocean at grid point 1.5°×1.5°during the last 44 a is analyzed.It is discovered that a majority of global ocean swell wave height exhibits a significant linear increasing trend(2-8 cm/decade),the distribution of annual linear trend of the significant wave height(SWH)has good consistency with that of the swell wave height.The sea surface wind speed shows an annually linear increasing trend mainly concentrated in the most waters of Southern Hemisphere westerlies,high latitude of the North Pacific,Indian Ocean north of 30°S,the waters near the western equatorial Pacific and low latitudes of the Atlantic waters, and the annually linear decreasing mainly in central and eastern equator of the Pacific,Juan.Fernandez Archipelago,the waters near South Georgia Island in the Atlantic waters.The linear variational distribution characteristic of the wind wave height is similar to that of the sea surface wind speed.Another find is that the swell is dominant in the mixed wave,the swell index in the central ocean is generally greater than that in the offshore,and the swell index in the eastern ocean coast is greater than that in the western ocean inshore, and in year-round hemisphere westerlies the swell index is relatively low.
Surface tidal currents in the open sea area to the east of the Zhoushan Islands measured with high frequency surface wave radar
SHEN Zhiben, WU Xiongbin, FEI Yuejun, XU Xing'an, CHEN Xiaofeng
2013, 32(10): 5-10. doi: 10.1007/s13131-013-0359-4
Based on the quasi-harmonic analysis of 11 d vector ocean currents obtained from two high frequency surface wave radars located at Zhujiajian Island and Shengshan Island,the spatial distribution characteristics of surface tidal currents in the open sea area to the east of the Zhoushan Islands of Zhejiang Province,China are studied.The following conclusions are drawn from the analysis:the tidal current pattern in the open sea area to the east of Zhoushan Islands is primarily regular semidiurnal,which is significantly affected by the shallow water constituents.The directions of the major axes of tidal current ellipses of M2 lie approximately in the NW-SE direction.With the increasing of distance away from the coast,the directions of the tidal current ellipses gradually shift toward the E-W direction.The tidal currents are mainly reversing currents.The spatial distribution of probable maximum current velocities decreases gradually from northeast to southwest which is basically in accordance with the spatial distribution of measured maximum current velocities.The residual currents near the coast are larger than those far away from the coast.The directions of the residual currents are basically north by east,and the angle to the due north increases gradually with the increasing distance away from the coast.The topography shows a certain impact on the spatial distribution of shallow water constituents,the rotation of tidal currents,the probable maximum currents and the residual currents.
Severe winter weather as a response to the lowest Arctic sea-ice anomalies
CHEN Hongxia, LIU Na, ZHANG Zhanhai
2013, 32(10): 11-15. doi: 10.1007/s13131-013-0360-y
Possible impact of reduced Arctic sea-ice on winter severe weather in China is investigated regarding the snowstorm over southern China in January 2008.The sea-ice conditions in the summer(July-September) and fall(September-November)of 2007 show that the sea-ice is the lowest that year.During the summer and fall of 2007,sea ice displayed a significant decrease in the East Siberian,the northern Chukchi Sea, the western Beaufort Sea,the Barents Sea,and the Kara Sea.A ECHAM5.4 atmospheric general circulation model is forced with realistic sea-ice conditions and strong thermal responses with warmer surface air temperature and higher-than-normal heat flux associated with the sea-ice anomalies are found.The model shows remote atmospheric responses over East Asia in January 2008,which result in severe snowstorm over southern China.Strong water-vapor transported from the Bay of Bengal and from the Pacific Ocean related to Arctic sea-ice anomalies in the fall(instead of summer)of 2007 is considered as one of the main causes of the snowstorm formation.
Assessing the global averaged sea-level budget from 2003 to 2010
LI Juan, ZUO Juncheng, CHEN Meixiang, TAN Wei, YANG Yiqiu
2013, 32(10): 16-23. doi: 10.1007/s13131-013-0361-x
A global mass balance(Greenland and Antarctica ice sheet mass loss,terrestrial water storage)and different sea-level components(observed sea-level from satellite altimetry,steric sea-level from Ishii data,and ocean mass from gravity recovery and climate experiment,GRACE)are estimated,in terms of seasonal and interannual variabilities from 2003 to 2010.The results show that a detailed analysis of the GRACE time series over the time period 2003-2010 unambiguously reveals an increase in mass loss from the Greenland ice sheet and Antarctica ice sheet.The mass loss of both ice sheets accelerated at a rate of(392.8±70.0)Gt/a during 2003-2010,which contributed(1.09±0.19)mm/a to the global mean sea-level during this time.The net terrestrial water storage(TWS)trend was negative over the 8 a time span,which gave a small positive contribution of(0.25±0.12)mm/a.The interannual variability of the global mean sea-level was at least partly caused by year-to-year variability of land water storage.Estimating GRACE-based ice sheet mass balance and terrestrial water storage by using published estimates for melting glaciers,the results further show that the ocean mass increase since 2003 has resulted half from an enhanced contribution of the polar ice sheets, and half from the combined ice sheet and terrestrial water storage loss.Taking also into account the melting of mountain glaciers(0.41 mm/a)and the small GRACE-based contribution from continental waters (0.25 mm/a),a total ocean mass contribution of(1.75±0.57)mm/a from 2003 to 2010 is found.Such a value represented 75% of the altimetry-based rate of sea-level rise over that period.The contributions to steric sea-level(i.e.,ocean thermal expansion plus salinity effects)are estimated from:(1)the difference between altimetry-based sea-level and ocean mass change and(2)the latest Ishii data.The inferred steric sea-level rate from(1)(1.41 mm/a from 2003 to 2010)did not agree well with the Ishii-based value also estimated here (0.44 mm/a from 2003 to 2010),but phase.The cause for such a discrepancy is not yet known but may be related to inadequate sampling of in situ ocean temperature and salinity measurements.
Global air-sea surface carbon dioxide transfer velocity and flux estimated using 17 a altimeter data and a new algorithm
YU Tan, HE Yijun, YAN Xiaohai
2013, 32(10): 24-33. doi: 10.1007/s13131-013-0362-9
The global distributions of the air-sea CO2 transfer velocity and flux are retrieved from TOPEX/Poseidon and Jason altimeter data from October 1992 to December 2009 using a combined algorithm.The 17 a average global,area-weighted,Schmidt number-corrected mean gas transfer velocity is 21.26 cm/h,and the full exploration of the uncertainty of this estimate awaits further data.The average total CO2 flux(calculated by carbon)from atmosphere to ocean during the 17 a was 2.58 Pg/a.The highest transfer velocity is in the circumpolar current area,because of constant high wind speeds and currents there.This results in strong CO2 fluxes.CO2 fluxes are strong but opposite direction in the equatorial east Pacific Ocean,because the air-sea CO2 partial pressure difference is the largest in the global oceans.The results differ from the previous studies calculated using the wind speed.It is demonstrated that the air-sea transfer velocity is very important for estimating air-sea CO2 flux.It is critical to have an accurate estimation for improving calculation of CO2 flux within climate change studies.
The vertical structure of the atmospheric boundary layer over the central Arctic Ocean
BIAN Lingen, MA Yongfeng, LU Changgui, LIN Xiang
2013, 32(10): 34-40. doi: 10.1007/s13131-013-0363-8
The tropopause height and the atmospheric boundary layer(PBL)height as well as the variation of inversion layer above the floating ice surface are presented using GPS(global position system)radiosonde sounding data and relevant data obtained by China's fourth arctic scientific expedition team over the central Arctic Ocean(86°-88°N,144°-170°W)during the summer of 2010.The tropopause height is from 9.8 to 10.5 km, with a temperature range between-52.2 and-54.1℃ in the central Arctic Ocean.Two zones of maximum wind(over 12 m/s)are found in the wind profile,namely,low-and upper-level jets,located in the middle troposphere and the tropopause,respectively.The wind direction has a marked variation point in the two jets from the southeast to the southwest.The average PBL height determined by two methods is 341 and 453 m respectively.These two methods can both be used when the inversion layer is very low,but the results vary significantly when the inversion layer is very high.A significant logarithmic relationship exists between the PBL height and the inversion intensity,with a correlation coefficient of 0.66,indicating that the more intense the temperature inversion is,the lower the boundary layer will be.The observation results obviously differ from those of the third arctic expedition zone(80°-85°N).The PBL height and the inversion layer thickness are much lower than those at 87°-88°N,but the inversion temperature is more intense,meaning a strong iceatmosphere interaction in the sea near the North Pole.The PBL structure is related to the weather system and the sea ice concentration,which affects the observation station.
The error source analysis of oil spill transport modeling: a case study
LI Yan, ZHU Jiang, WANG Hui, KUANG Xiaodi
2013, 32(10): 41-47. doi: 10.1007/s13131-013-0364-7
Numerical modeling is an important tool to study and predict the transport of oil spills.However,the accuracy of numerical models is not always good enough to provide reliable information for oil spill transport. It is necessary to analyze and identify major error sources for the models.A case study was conducted to analyze error sources of a three-dimensional oil spill model that was used operationally for oil spill forecasting in the National Marine Environmental Forecasting Center(NMEFC),the State Oceanic Administration, China.On June 4,2011,oil from sea bed spilled into seawater in Penglai 19-3 region,the largest offshore oil field of China,and polluted an area of thousands of square kilometers in the Bohai Sea.Satellite remote sensing images were collected to locate oil slicks.By performing a series of model sensitivity experiments with different wind and current forcings and comparing the model results with the satellite images,it was identified that the major errors of the long-term simulation for oil spill transport were from the wind fields, and the wind-induced surface currents.An inverse model was developed to estimate the temporal variability of emission intensity at the oil spill source,which revealed the importance of the accuracy in oil spill source emission time function.
Optical detection of Prorocentrum donghaiense blooms based on multispectral reflectance
TAO Bangyi, PAN Delu, MAO Zhihua, SHEN Yuzhang, ZHU Qiankun, CHEN Jianyu
2013, 32(10): 48-56. doi: 10.1007/s13131-013-0365-6
Prorocentrum donghaiense is one of the most common red tide causative dinoflagellates in the Changjiang (Yangtze)River Estuary and the adjacent area of the East China Sea.It causes large-scale blooms in late spring and early summer that lead to widespread ecologic and economic damage.A means for distinguishing dinoflagellate blooms from diatom(Skeletonema costatum)blooms is desired.On the basis of measurements of remote sensing reflectance[Rrs(λ)]and inherent optical parameters,the potential of using a multispectral approach is assessed for discriminating the algal blooms due to P.donghaiense from those due to S.costatum.The behavior of two reflectance ratios[R1=Rrs(560)/Rrs(532)and R2=Rrs(708)/Rrs(665)], suggests that differentiation of P.donghaiense blooms from diatom bloom types is possible from the current band setup of ocean color sensors.It is found that there are two reflectance ratio regimes that indicate a bloom is dominated by P.donghaiense:(1)R1>1.55 and R2<1.0 or(2)R1>1.75 and R2≥1.0.Various sensitivity analyses are conducted to investigate the effects of the variation in varying levels of chlorophyll concentration and colored dissolved organic matter(CDOM)as well as changes in the backscattering ratio (bbp/bp)on the efficacy of this multispectral approach.Results indicate that the intensity and inherent optical properties of the algal species explain much of the behavior of the two ratios.Although backscattering influences the amplitude of Rrs(λ),especially in the 530 and 560 nm bands,the discrimination between P. donghaiense and diatoms is not significantly affected by the variation of bbp/bp.Since aCDOM(440)in coastal areas of the ECS is typically lower than 1.0 m-1 in most situations,the presence of CDOM does not interfere with this discrimination,even as SCDOM varies from 0.01 to 0.026 nm-1.Despite all of these effects,the discrimination of P.donghaiense blooms from diatom blooms based on multispectral measurements of Rrs(λ) is feasible.
Research on cloud computing and services framework of marine environmental information management
SHI Suixiang, LIU Yang, WEI Hongyu, QIAO Baiyou, WANG Guoren, XU Lingyu
2013, 32(10): 57-66. doi: 10.1007/s13131-013-0366-5
Based on the features of marine environmental data and processing requirements,a cloud computing architecture of marine environment information is proposed,which provides a new cloud technology framework for the integration and sharing of marine environmental information resources.A physical layer,software platform layer and an application layer are illustrated systematically,at the same time,a corresponding solutions for many difficult technical problems such as parallel query processing of multi-dimensional,spatiotemporal information,data slice storage,software service flow customization,analysis,reorganization and so on.A prototype system is developed and many different data-size experiments and a comparative analysis are done based on it.The experiment results show that the cloud platform based on this framework can achieve high performance and scalability when dealing with large-scale marine data.
Particulate organic carbon export flux by 234Th/238U disequilibrium in the continental slope of the East China Sea
BI Qianqian, DU Jinzhou, WU Ying, ZHOU Jing, ZHANG Jing
2013, 32(10): 67-73. doi: 10.1007/s13131-013-0303-7
234Th is widely used to quantify the magnitude of upper ocean particulate organic carbon(POC)export in oceans.In the present work,the rates of particulate organic carbon export were measured based on the distribution patterns of 234Th/238U disequilibrium in the water column within the continental slope of the East China Sea(ECS)during May 2011.The profiles of particulate and dissolved 234Th activities at all three stations showed a relative deficit with respect to 238U in the upper 100 m of the water column.The dissolved 234Th scavenging rates and the particulate 234Th removal rates and their residence times were calculated by a one-dimensional steady state model.The results showed that the dissolved 234Th scavenging rates and the particulate 234Th removal rates ranged from 12.4-61.4 dpm/(m3·d)and from 3.8-21.8 dpm/(m3·d), respectively.The residence times of dissolved and particulate 234Th were in the range of 3.4-158 d and 63.7-96.5 d,respectively.Combined with the measurement of POC/234Th ratios of suspended particles,POC export flux(calculated by carbon)from the euphotic zone was estimated in the study region,which ranged from 4.14-14.7 mmol/(m2·d),with an average of 8.21 mmol/(m2·d),occupying 35% of the prime productivity in the study area.The results of this study can provide new information for better understanding the carbon biogeochemical cycle within the continental slope of the ECS.
Confounding response of macrofauna from a confluence of impacts: brine and sewage pollution
Rodrigo Riera, Fernando Tuya, Myriam Rodríguez, Óscar Monterroso, Eva Ramos
2013, 32(10): 74-81. doi: 10.1007/s13131-013-0368-3
Throughout the shores of the world,a confluence of different sources of pollution is common,e.g.,through outlets releasing brine,industrial,and domestic sewage.In this study,we assessed whether a combined disposal of domestic sewage and brine altered the patterns of abundance and assemblage structure of subtidal macrofauna inhabiting sandy seabeds on the south coast of Gran Canaria(Canary Islands,NE Atlantic Ocean).Samples were collected in two surveys(May 2008 and January 2009)at three distances(0,15,and 30 m)away from the discharge point.Macrofaunal abundances showed different patterns with varying proximity from the disposal point in the two surveys.In May 2008,lower abundances were observed at 0 m(53.89±46.82 ind.)than at 15 m(120±91.7 ind.)and 30 m(283.89±189.33 ind.)away from the disposal point.In January 2009,however,higher abundances were observed at 0 m(131.33±58.69 ind.)than at 30 m(100±24.44 ind.)and 15 m(84.78±58.39 ind.)away from the disposal point.Significant differences in macrofaunal assemblage structure were found with varying proximity from the discharge point in both surveys.The effect of proximity from the disposal point was confounded by changes in sedimentary composition between surveys,which contributed to explain differences in macrofaunal abundances and assemblage structure with varying proximity from the discharge point.As a result,confounding drivers of macrofaunal assemblage structure,here,changes in sediment composition,accounted for changes in macrofaunal abundances and assemblage structure with varying proximity from a combined disposal point of brine and sewage.
Growth performance of the clam, Meretrix meretrix, breedingselection populations cultured in different conditions
WANG Chao, CHAI Xueliang, WANG Hongxia, TANG Baojun, LIU Baozhong
2013, 32(10): 82-87. doi: 10.1007/s13131-013-0369-2
A breeding-selection program for the clam,Meretrix meretrix,was conducted since 2004.Two of the selection populations were generated with the shell color pattern as an additional selection criterion and named as SP(purple stripes)population and SB(black dots)population.The third-generation SP and SB populations(08G3SP and 08G3SB,respectively)were cultured at two commercial clam farms and a nursery pond and their shell lengths were compared.08G3SB clams had significantly larger sizes than 08G3SP clams at commercial clam farms(p<0.05),yet 08G3SB individuals were significantly smaller than 08G3SP individuals at the nursery pond(p<0.05).Then,we examined the growth of the fourth-generation SP and SB populations(10G4SP and 10G4SB,respectively)at a commercial farm,and found that the shell lengths of the 10G4SB clams increased at a significantly higher growth rate than the 10G4SP clams(p<0.05)from May to September,when the water temperature was between 24.2-27.5℃,while 10G4SB lost the growth advantage in the other months.These results indicated that SP and SB populations responded differently to environmental factors,so it is beneficial for the clam farmers to select a suitable population according to the culture environment.Furthermore,a diallel mating of the SB and SP populations was designed to investigate whether their hybrid population would show heterosis.However,the heterosis was not shown in this study,which might result from the slight genetic divergence between SB and SP populations.
Research Notes
Diagnosis of nervous necrosis virus in orange-spotted grouper, Epinephelus coioides, by a rapid and convenient RT-PCR method
MU Yinnan, LIN Kebing, CHEN Xinhua, AO Jingqun
2013, 32(10): 88-92. doi: 10.1007/s13131-013-0370-9
Viral nervous necrosis(VNN)causes high mortality in marine fish,especially in the grouper,worldwide and in China.Since there is no effective vaccine or drug to deal with VNN,early detection and prevention is important to block its outbreak.In this study,a reverse transcription-polymerase chain reaction(RT-PCR) was developed for the rapid,convenient,and sensitive detection of the VNN pathogen,nervous necrosis virus(NNV),in the grouper.The whole process was completed within 3.5 h from the RNA extraction to PCR product visualization.The detection limit of this method was 200 copies of NNV RNA standard, which corresponded to 200 copies of virus particles.This RT-PCR method was specific to the NNV detection with no cross-reactivity to other fish viral disease pathogens,such as infectious pancreatic necrosis virus (IPNV),infectious hematopoietic necrosis virus(IHNV),spring viraemia of carp virus(SVCV),epizootic haematopoietic necrosis virus(EHNV),and large yellow croaker iridovirus(LYCIV).With this method,the orange-spotted grouper(Epinephelus coioides)fry from hatcheries with or without incidence of the VNN epidemic in Fujian Province were detected.The results showed that all or 93% of the fry from the two hatcheries with incidence of the epidemic were diagnosed as positive,while 40% or 25% of fry from the two hatcheries without the VNN epidemic were also detected as NNV positive,indicating that this RT-PCR method can be used for rapid,sensitive detection of NNV infection and applied in the VNN epidemic alert.