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1.
After the winter and summer current structures on two or three latitudinal sections in Taiwan Strait were obtained from the measured current data, the seawater fluxs through the sections were calculated. In summer, the currents in the central and northern part of Taiwan Strait normally flow northward at a net flux of 3.32×106m3/s. In winter, the high temperature and salinity Kuroshio and South China Sea water enter Taiwan Strait from the southem section at 1.69×106m3/s and 0.59×106 m3/s respectively, while the East China Sea water enters Taiwan Strait from the northern section at 1.02×106m3/s. About 0.40×106 m3/s of the seawater enters the South China Sea along the coast of Fujian and Guangdong; the other 0.62×106 m3/s of the seawater is mixed with the Kuroshio water and the South China Sea water in the northern sea areas. The net northward flux is 1.74×106m3/s in winter.  相似文献   

2.
The International Eq一lation of State of Seawater,1980 and the PraeticalSalinity Scale,1978 have been adoPted by theUNESCO江CES沼COR八APSOJoint Panel ono‘eanogral,hie Tables and Standards(JPOTS),and endorsed bythese organizati6ns(Miller‘〕and Poisson,1981;Uneseo,1981).Th已new equa-tion and the Praetieal Salinity Seale are to be used for all values Published fromJan .1,1982 .The new equation 15 aeeurate for use in all oeeanie surfaee waters,but eannot be aeeurately aPPlied to…  相似文献   

3.
xiODUonONThemaoreleInent(oxygen)ofldeinthemarineeresySteInisCycledalongapartho-larrouteinWhwhthethetcanbedrawnfromtheexternlenvirDnmentintoorgan-isim,andthenberetumedtotheenvbonmentfromtheorganisrns.TheDocontentinseawatCfisinIlUentalbyorganisms,imtS,temPeratureandoxidation.So,studyonDoisoftoortanceinoasnographyastheDofluxisofgreatsignfonceinmarinebiogeochdricalcydes.'MareRIAnooMEmOorlnthisstudy,datafroml98O~l992multi-disdplinaryinvestigationsinthecenthel,northeastem,andsouthernSrswe…  相似文献   

4.
A new kinetic spectrophotometric method has been developed for the determination of iron (Ⅲ). The method is based on the catalytic effect of iron (Ⅲ) on the oxidation of weak acid brilliant blue dye (RAWL) by KIO4 in acid medium. The advantages of the proposed method are that it is sensitive, accurate, rapid, inexpensive, can be operated under room temperature and has a large determination concentration range compared to other techniques. The obtained optimum conditions are pH 3.15, RAWL (200 mgL-1) 5.00mL, Potassium periodate solution (0.01 molL-1) 0.30mL, phenanthroline (0.02molL-1) 1.00mL, reaction temperature 25℃ and reaction time 7 miu. With this method iron could quantitively be determined in the range 0.00-0.02 mgL-1, the detection limit being 4.10×10-10mL-1. The relative standard deviations (RSD) in five replicate determinations for 3 μgL-1 and 5μgL-1 iron (Ⅲ) are 3.1% and 1.9%, respectively. The method has been applied to the determination of iron (Ⅲ) in tap water samples and seawater samples (from the South China Sea), the recovery rates being 98.0% and 100.5%, respectively.  相似文献   

5.
INTRODUCTIONTheYellowSeaandtheEastChinaSea (ECS)aremarginalseasofthenorthwestPacificandhaveexpansivecontinentalshelves .TheuniqueandstrikingfeaturesoftheYellowSeaandtheECSarethattheyhavestrongtidalcurrent;aresubjecttostrongmonsooninfluence ;andreceiveinflowfromthebiggestriverinChina ,theChangjiangRiver ;andthatthefamouswesternboundarycurrent,theKuroshio ,passesthroughtheECS ,withitsbranchesintrudingupwardintothecontinentalshelfareas.Generallyspeaking ,thewaterexchangecapacityofthe…  相似文献   

6.
mODUCTIONTheislandsOfHaitan,Yuo,Dalian,DowiangandCaoguinPingtanCoUntyofFu-jianProvincearetogetherthewhtoasPingtan(25'l5'-25o45'E,l19"32'-12o"lo'N,EaStChinaSea).AmngthemHaitangIslanisthedrinoneinPingtanCotmty,andthelargestinFuianProvince.RngtanhaSanatuIalfishinggroUn(SeduMOUntaln)beingrenownedboghoutthecOUnnyandawelldeVfoPedaqUacultUreindusny.Pingtanwa-tersresotirceswerestirveyedforthefirsttimebytheauthorssothattheknowedgegainedcanbeaPPliedforbettereaploitahon,PIDechon,andde…  相似文献   

7.
Ｉ．ＩＮＴＲＯＤＵＣＴＩＯＮ“Ａｇｅｎｄａ２１”ｒｅｃｏｇｎｉｚｅｓｔｈｅｉｍｐｏｒｔａｎｃｅｏｆｌａｎｄｂａｓｅｄｓｏｕｒｃｅｐｏｌｕｔａｎｔｓｔｏｍａｒｉｎｅｐｏｌｕｔｉｏｎ．Ｃｏａｓｔａｌｗａｔｅｒｉｓｏｆｇｒｅａｔｓｉｇｎｉｆｉｃａｎｃｅ...  相似文献   

8.
The influence of land-based source pollutants to marine ecological environment is principally in coastal or enclosed sea wates. Flux of land-based source pollutants into the sea will be effected due to social and economic development in the Tumen River basin. Pollutant type and primary pollution factor of the Tumen River in Northeast China is described by weighted coefficient method in this paper. The results indicate that the river is organic pollution type and primary pollution factor is COD. Fresh water fraction proves that the estuary is not affected by tide cycle. COD annual flux entering the Sea of Japan calculated by zero-dimension model in 1993 was 90.50 × 103 tons. It is estimated with emission coefficient method that the COD will be 176.4 × 103 and 458.6 × 103 tons for the years of 2000 and 2010 respectively. This work is sponored by the Open Fund of State Key Laboratory on Environmental Aquatic Chemistry.  相似文献   

9.
When cultured under certain environmental conditions (25°C, light intensity 80 μmol/m2·s, LD 12/12, in enriched seawater medium with 7×10−4 mol/L NO3−N, 1.56×10−4 mol/L, PO4−P and supplements of other elements like Mn, Fe, I, etc.), male and female gametophytes ofU. pinnatifida kept growing vegetatively and propagated fast at average daily fresh weight increase rate of about 20%. The empirical formulaG m=G o·3m was established to estimate the output of vegetative gametophytes. Vigorous vegetative gametophyte cells began to form reproductive structures (oogonium and spermatangium, when the temperature was lower than 25°C and other environmental factors were kept optimal. The sufficient supply of gametophyte cells provided enough seeds for raisingUndaria sporelings on production scale. Controlled cross-breeding experiments using selected male and female gametophyte clones which increase their cell number by mitosis instead of meiosis were also carried out in vitro. Juvenile sporophytes from the cross-breeding had almost the same length and width increase rates as those of the control. The fact that vegetative gametophytes can be purposely selected, propagated quickly, cross-bred, with the resulting sporophytes having almost the same characteristics leads to a new way to select desiredUndaria strains for long time use without losing the desired economic characteristics. Contribution No. 2696 from the Institute of Oceanology, Chinese Academy of Sciences. Supported by National Natural Science Foundation of China.  相似文献   

10.
Eighy-one CTD profiles gathered in springtime were used for northem East China Sea tbermohalinefinestructure studies indicating that the finestructure properties vaned with region and depth, as shown infinesructure specra, distribution of Cox numbers etc..Some results closely wiated to distribution of watermasses and Analysis of two typical profiles revealed differenes in autospectra of temperature,salihity and potential density gradients, probobility distribution of temperature finestructure gradient,Cox numberc.etc. The probability density function of vertical temperature gradients, which varied withsample interval, is given. The variances of temperatare finestructare gradient are used to estimate the lat-eral diffusivity and lateral temperatare flux, which were 10.3 (m~2/s) and 5.5×10~(-4) (℃ m/s),respectivly.  相似文献   

11.
GPS measurement,an effective method for surveying glacier surface topography,has been applied in some glaciers for many years.The Shuiguan River No.4 glacier,a small glacier with its area of 1.84 km2 in 1972,located in the east of the Qilian Mountains,China,was selected to study its ice elevation change using GPS measurement in 2007.This study was conducted on the ablation area with GPS-measured area 0.5 km2.The ice elevation change of the glacier was obtained by comparing the DEM obtained by a 1:50 000 topographic map made in 1972 with the DEM by GPS-measured data acquired in 2007.The differences of the two DEMs showed the thinning condition of the glacier was apparent.The mean thinning was 15±8 m with the mean thinning rate of 0.42±0.22 m a-1 for 1972-2007 in the measurement area,which equaled 0.38±0.20 m yr-1 in water equivalent(w.e.).The prominent thinning occurred on the south part of the glacier,which was the area near the glacier terminus with the maximum thinning of 41±8 m.Assuming the thinning value of 15±8 m for the glacier area below 4640 m a.s.l.,the wasting ice mass was calculated to be 6.4±3.2×10-3 km3 for 1972-2007,corresponding to 5.7±2.8×10-3 km3 w.e.,which meant that the montane runoff released by the glacier was at least 5.7±2.8×106 m3 between 1972-2007.  相似文献   

12.
^234Th-^238U disequilibria were applied to examine the particle dynamics in the euphotic zone of the central South China Sea during the spring 2002 cruise. The particulate organic carbon （POC）, ^234Th （including both dissolved and particulate） and ^238U in the water column at three stations were determined. The profiles of ^234Th/^238U activity ratio at the three stations all showed consistent ^234Th deficit as compared to ^238U in the upper 100 m water column. Based on the profiles of the dissolved and particulate ^234Th and a steady state box model, the dissolved ^234Th scavenging rates, the particulate ^234Th removal rates and their resident times were quantified. It was found that the POC downward export fluxes out of the upper 100 m euphotic zone ranged from 9.40 to 14.78 mmol·m^-2·d^-1. The results from this study provide new information for our understanding of carbon biogeochemical cycle in the South China Sea.  相似文献   

13.
The research on the present situation of soil and water development and utilization in Shiyang River Basin shows that water resources and eco-environment situation in this area are near the edge of collapse. Since the water crises occurred in the 1970s, problems caused by continuous decrease of water resources have been becoming serious year by year and eco-environment crisis occurred as a consequence. Up to now, 10 380ha of irrigated lands have been abandoned due to sand coverage and water shortage in the basin. Ground water was over exploded in Wuwei and Minqin because of water shortage. Ground water table in many places dropped under 5m (which is the ecology water table level), thus about 3000ha of Elaeagnus angustifolia forest come to dead and another 5800ha become feeble, and wind-drift sand near the oasis become alive. According to the current situation, if water utilization scope was not enlarged, a water transfer volume of 600×106m3/a from other areas will be suitable to keep water resources and eco-environment safety in the basin, and also 70×106m3/a will be left as spare water. Under this condition the water resources and eco-environment of the basin can reach the critical safety line of 2.032×109m3/a; or if 180×106m3 of water can be transferred from other areas, the water resources can reach the safety warning line of 1.732×109m3/a. Foundation item: Under the auspices of the National Natural Science Foundation of China (No. 40235053) and Lanzhou Jiaotong University "Qinglan" Foundation Biography: ZHANG Ji-shi (1963-), male, a native of Tongwei of Gansu Province, senior engineer, specialized in water resources and climate change in Northwest China. E-mail: zjs1963@yahoo.com.cn; hangjs@mail.lzjtu.cn  相似文献   

14.
Partial pressure of CO2 （pCO2） was investigated in the Changjiang （Yangtze River） Estuary, Hangzhou Bay and their adjacent areas during a cruise in August 2004, China. The data show that pCO2 in surface waters of the studied area was higher than that in the atmosphere with only exception of a patch east of Zhoushan Archipelago. The pCO2 varied from 168 to 2 264 μatm, which fell in the low range compared with those of other estuaries in the world. The calculated sea-air CO2 fluxes decreased offshore and varied from -10.0 to 88.1 mmol m^-2 d^-1 in average of 24.4 ± 16.5 mmol m^-2 d^-1. Although the area studied was estimated only 2 × 10^4 km^2, it emitted （5.9 ± 4.0） × 10^3 tons of carbon to the atmosphere every day. The estuaries and their plumes must be further studied for better understanding the role of coastal seas playing in the global oceanic carbon cycle.  相似文献   

15.
A new kinetic-spectrophotometric method is proposed for the determination of copper （ Ⅱ ）. The method is based on the catalytic effect of copper （ Ⅱ ） on the oxidation of weak acid brilliant blue dye （RAWL） by hydrogen peroxide. The copper （ Ⅱ ） can be determined spectrophotometrically by measuring the decrease of absorbance of RAWL at λ = 626 nm using the fix-time method. The optimum reaction conditions are as follows： pH 7.20, buffer solution NaOH-KH2PO4, RAWL （200 mgL-1） 5.00 mL, H2O2 （30%） 0.50 mL, reaction temperature 80 ？？ and reaction time 20 min. The linear range of this method is between 0 μg L^-1 and 12 μg L^-1 and the limit of detection is 0.011 μg L-1, the relative standard deviation （RSD） in five replicate determinations for 2 and 8 μg L-1 copper （ Ⅱ ） are 3.2% and 2.3%, respectively. Twenty ions do not interfere in the determination of copper （ Ⅱ ）. The method has been applied satisfactorily to the determination of copper （ Ⅱ ） in freshwater samples （tap water and Yellow River water from Lijin, Shandong, China） and seawater samples （from the South China Sea）, the recovery rates are 98.0%, 102.5% and 96.0%, respectively.  相似文献   

16.
The densities of 36 water samples from the Huanghe River estuary and Bohai Bay were determinedby a magnetic float densimcter under three temperatures from 15℃ to 25℃.All the measured densities ofsamples were greater than that of the values calculated from the International Equation of State of Seawater.The differences between the measured and calculated densities increased with the decrease of salinities.The dif-ferences appeared exponentially correlated with[Ca~(2+)]/s,[Mg~(2+)]/s and[SO_4~(2-)]/s,and had"s"type curverelationship with the alkalinity in all salinity range.But in the salinity ranging from 25.72 to 31.57,therelationships were all linear.The density difference can be estimated from the equation △ρ（10~3kg·m~(-3)）=（-2.79+236.5([Ca~(2+)]/s)/(-9.7464×10~（-3）+[Ca~(2+)]/s).It was the high alkalinity and[Ca~(2+)]/s that resulted in the measured densi-ties of seawaters being higher than the calculated densities in the Huanghe estuary and Bohai Bay.  相似文献   

17.
Sample seawater containing trace methyl mercury was acidified and adsorbed on hydrosulfo-cotton, washed with hydrochloric acid, extracted by benzene and dried, and then determined by a gas chromatograph with electron capture detector. This method, which can detect a minimum concentration of 0.1×10−10%, can be used to monitor the 10−10% content of methyl mercury in seawater.  相似文献   

18.
During the two cruises in March and July of 2011, the tidal cycling of turbulent properties and the T/S profiles at the same location in seasonally stratified East China Sea (ECS) were measured synchronously by a bottom-mounted fast sampling ADCP (acoustic Doppler current profiler) and a RBR CTD (RBR-620) profiler. While focusing on the tide-induced and stratification’s impact on mixing, the Reynolds stress and the turbulent kinetic energy (TKE) production rate were calculated using the ‘variance method’. In spring, the features of mixing mainly induced by tides were clear when the water column was well-mixed. Velocity shear and turbulent parameters intensified towards the seabed due to the bottom friction. The components of the velocity shear and the Reynolds stress displayed a dominant semi-diurnal variation related to velocity changes caused by the flood and ebb of M2 tide. Stratification occurred in summer, and the water column showed a strongly stratified pycnocline with a characteristic squared buoyancy frequency of N2 ～ (1–6) × 10?3 s?2. The components of the velocity shear and the Reynolds stress penetrated upwards very fast from the bottom boundary layer to the whole water column in spring, while in summer they only penetrated to the bottom of the pycnocline with a relatively slow propagation speed. In summer, the TKE production within the pycnocline was comparable with and sometimes larger than that in the well-mixed bottom layer under the pycnocline. Considering the associated high velocity shear, it is speculated that the mixing in the pycnocline is a result of the local velocity shear.  相似文献   

19.
During the 13th (1996–1997) and the 19th (2002–2003) Chinese National Antarctica Research Expeditions, we collected 60 discrete surface seawater samples along the cruise from the Chanjiang River (Yangtze) estuary (30°59′S, 122°26′E) through Taiwan Strait, the South China Sea, and the Eastern Indian Ocean to Prydz Bay, Antarctica (69°10′S, 74°30′E), and analyzed them for the 226Ra specific activity. The 226Ra specific activity of the Chanjiang River estuary surface water (3.15 Bq/m3) was found to be the highest among all the surface samples because of the desorption of 226Ra from riverine particles. Between Chanjiang River estuary and 40°S, 226Ra specific activity was found to be relatively uniform with a mean value of 1.07 Bq/m3 (n = 19, SD = 0.14), similar to that of the open ocean. From 40°S to 65°S, 226Ra specific activity increased intensively, then decreased moderately further southwards. Near the Antarctic shore, it increased again, to 2.31 Bq/m3. This distribution was controlled by a combination of deep water upwelling, Southern Ocean fronts, water mixing and the continental 226Ra import. In Prydz Bay and the adjacent sea area, the mean 226Ra activity value was 2.26 Bq/m3 (n = 31, SD = 0.28), with a relatively higher value outside of the bay and low 226Ra activity value in the center of the bay. This was consistent with the topography and hydrological setting of the bay. In addition, we extended the study area northward to the Arctic, by combining the published 226Ra dataset for surface water from the Bering Sea to the Japan Sea. We also discuss the 226Ra distribution of high latitude oceanic surface water and its mechanisms.  相似文献   

20.
ＩＮＴＲＯＤＵＣＴＩＯＮＰｈｙｔｏｐｌａｋｔｏｎｈａｓａｋｅｙｒｏｌｅｉｎｔｈｅｍａｒｉｎｅｅｃｏｓｙｓｔｅｍａｓｔｈｅｂａｓｉｃｐａｒｔｉｎｔｈｅｆｏｏｄｃｈａｉｎ ,ｗｈｉｃｈｉｓｉｍｐｏｒｔａｎｔｉｎｆｏｒｍａｔｉｏｎｆｏｒａｓｓｅｓｓｉｎｇｐｒｏｄｕｃｔｉｖｉｔｙｐｏｔｅｎｔｉａｌａｎｄｆｉｓｈｅｒｙｒｅｓｏｕｒｃｅｓ.Ｐｈｙｔｏｐｌａｎｋｔｏｎａｌｓｏｈａｓａｎｉｍｐｏｒｔａｎｔｒｏｌｅｉｎｔｈｅｃａｒｂｏｎｂｉｏｇｅｏｃｈｅｍｉｃａｌｃｙｃｌｅ,ｂｅｃａｕｓｅｉｔｃａｎａｂｓｏｒｂａｌａ…  相似文献   

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