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Depressing defocusing effect in microscopy by bi-orthogonal wavelet transform

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Particuology 2012年第5期10卷 644-647页

作者： Hequan Sun Jiguang wang Ruoli Shao department of military oceanography Dalian Naval AcademyDalian 116018China Design Institute of Civil Engineering and Architecture Dalian University of TechnologyDalian 116023China

For different dimensions, heights and irregular shapes, small and large particles cannot be viewed simultaneously as sharp images under the microscope due to optical defocusing effects. Bi-orthogonal wavelet transform is used in this paper to depress such defocusing effect by merging the wavelet coefficients of the image series. The algorithm is presented in detail, using SWE（13,7） and CDF（2,2）, and a few particle images are provided to validate the proposed method.

关键词： Defocusing effectWavelet transformBi-orthogonal waveletCDF(2.2)SWE( 13 7 )

Algorithm for Harmonic Tidal Analysis along T/P Tracks： Taking Differences of Observed Sea Surface Heights at Adjacent Points as Observations

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Geo-Spatial Information Science 2008年第1期11卷 17-20页

作者： XU Jun BAO Jingyang LIU Yanchun YU Caixia department of hydrography and cartography Dalian Naval Academy 667 Jiefang Road Dalian 116018 China 不详

An algorithm （differential mode） is presented for the improvement of harmonic tidal analysis along T/P tracks, in which the differences between the observed sea surface heights at adjacent points are taken as observations. Also, the observation equations are constrained with the results of the crossover analysis; the parameter estimations are performed at 0.1° latitude intervals by the least squares. Cycle 10 to 330 T/P altimeter data covering the China Sea and the Northwest Pacific Ocean （2°-50° N,105°-150° E） are adopted for a refined along-track harmonic tidal analysis, and harmonic constants of 12 constituents in 8 474 points are obtained, which indicates that the algorithm can efficiently remove non-tidal effects in the altimeter observations, and improve the precision of tide parameters. Moreover, parameters along altimetry tracks represent a smoother distribution than those obtained by traditional algorithms. The root mean squares of the fitting errors between the tidal height model and the observations reduce from 11 cm to 1.3 cm.

关键词： satellite altimetry T/P harmonic tidal analysis differential mode

Seasonal export fluxes of size-fractionated particulate derived from polonium-210: A case study in Xiamen Bay

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Chinese Journal of Oceanology and Limnology 2010年第2期28卷 379-386页

作者：杨伟锋黄奕普陈敏邱雨生 department of oceanography Xiamen University

Size-fractionated 210Po and 210Pb, in the size fractions >0.4 μm, >2 μm and >10 μm, were examined to determine the seasonal variability of particulate fluxes in Xiamen Bay. Good correlations between 210Po and particulate organic carbon (POC) or non-Particulate Organic Matter (nPOM) suggested that 210Po can be used to trace the export fluxes of POC and nPOM. Both steady-state (SS) model and nSS model were used to evaluate fluxes of size-fractionated 210Po, results showed that nSS model was better than the SS model in coastal areas. Based on the nSS model, size-fractionated POC fluxes decreased with increasing particle size. For the particle size studied, maximum POC fluxes occurred in autumn, followed by spring, winter, and summer. Fluxes of nPOM were an order of magnitude higher than the corresponding size-fractionated POC fluxes. Differences between size-fractionated nPOM fluxes indicated that hydrodynamic conditions were the main factor regulating transportation of particulate out of the inner Bay. In winter most particulates, including >10 μm particles, were transported under the strongest hydrodynamic conditions. In contrast, only a fraction of the <2 μm particulates were transported from the inner Bay in spring. This study suggested that 210Po is a powerful tracer of seasonal particulate export in coastal seas.

关键词： POC 210Po 210Pb thorium size fractionation

Effect of Sea Level Variation on Tidal Characteristic Values for the East China Sea

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海洋工程：英文版 2003年第3期17卷 369-382页

作者：于宜法俞聿修左军成万振文陈宗镛 The State Key Laboratory of Coastal and Offshore Engineering oceanography department First Institute of oceanography

Tidal waves in the East China Sea are simulated numerically with POM(Princeton Ocean Model) model for normal mean sea level, 30 cm higher, 60 cm higher, and 100 cm higher, respectively, and the simulated result is compared with the harmonic analysis result of hourly sea level data from 19 tide gauges for more than 19 years. It is indicated that the long-term mean sea level variation affects notably tidal waves in this region. Generally, the tidal amplitude increases when the mean sea level rises, but this relationship may be inverse for some sea areas. The maximal variation of tidal amplitude takes place in the zones near the Fujian coast and the Zhejiang coast, rather than the shallowest Bohai Sea. The maximum increase of M2 amplitude can exceed about 15 cm corresponding to the 60 cm rise of the mean sea level along the Fujian coast. The other regions with large variations of tidal amplitude are those along the Jiangsu coast, the south-east coast of Shandong, and the south-east coast of Dalian. The propagation of tidal waves is also related to mean sea level variation, and the tidal phase-lag decreases generally when the mean sea level rises. Almost all the regions where the tidal phase-lag increases with rising mean sea level are close to amphidromic points, meanwhile the spatial area of such regions is very small. Because the influence of mean sea level variation upon tidal waves is spatially marked, such spatial effect should be considered in calculation of the tidal characteristic value and engineering water level. In the region where the amplitudes of the major tidal constituents increase, the probable maximum high water level becomes higher, the probable maximum low water level becomes lower, and both design water level andcheck water level increase obviously. For example, the design water level at Xiamen increases by 13.5 cm due to the variation of tidal waves when the mean sea level rises 60 cm, the total increase of design water level being 73.5 cm.

关键词： East China Sea mean sea level tidal wave variation tidal characteristic value engineering water level

Oceanic Origin of A Recent La Nin a-Like Trend in the Tropical Pacific

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Advances in Atmospheric Sciences 2011年第5期28卷 1109-1117页

作者：张丽萍吴立新于立三 Physical oceanography Laboratory Ocean University of China Qingdao 266100 department of oceanography Woods Hole Oceanography Institute MA 02543 USA

Global ocean temperature has been rising since the late 1970s at a speed unprecedented during the past century of *** accelerated warming has profound impacts not only on the marine ecosystem and oceanic carbon uptake but also on the global water cycle and *** this rapid warming period,the tropical Pacific displays a pronounced La Nin a-like trend,characterized by an intensification of west-east SST gradient and of atmospheric zonal overturning circulation,namely the Walker *** La Nin a-like trend differs from the El Nin o-like trend in warm climate projected by most climate models,and cannot be explained by responses of the global water cycle to warm *** results of this study indicate that the intensification of the zonal SST gradient and the Walker circulation are associated with recent strengthening of the upper-ocean meridional overturning circulation.

关键词： tropical Pacific warming trend hydrological cycle subtropical tropical cell

Effect of Sea Level Variation on Calculation of Design Water Level

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China Ocean Engineering 2001年第3期16卷 383-394页

作者：左军成于宜法鲍献文刘德辅 department of oceanography Ocean University of Qingdao

The long-term variation and seasonal variation of sea level have a notable effect on the calculation of engineering water level. Stich an effect is first analyzed in this paper. The maximal amplitude of inter-annual anomaly of monthly mean sea level along the China coast is larger than 60 cm. Both the storm surge disaster and cold wave disaster are seasonal disasters in various regions, so the water level corresponding to the 1% of the cumulative frequency in the cumulative frequency curve of hourly water level data for different seasons in various sea areas is different from design water level., for example, the difference between them reaches maximum in June, July and August for northern sea area, and maximum in September, October and November for Southern China Sea, The hourly water level data of 19 gauge stations along the China coast are analyzed. Firstly, the annual mean sea level for every station is obtained; secondly, linear changing rates of annual mean sea level are obtained with the stochastic dynamic method; thirdly, the astronomical tide and storm surge tide are obtained by subtracting the linear fitting part from the original hourly data, finally, two distributions corresponding to the astronomical tide and wind tide are obtain ed according to whether the astronomical tide and storm tide are correlative or not. So the two check water levels are obtained with the joint probability method, The maximal difference between the two water levels of 100 years' recurrence is more than 30 cm. Both of the two check water levels have disadvantages in the use of observation data, so the mean value is suggested to be taken as the final check water level. A comparison between the two check-water levels indicates that the effect of sea level variation upon design water level and check water level is larger than 80 cm at some stations.

关键词： engineering water level sea level stochastic dynamic residual level joint probability

Seasonal variability in CDOM absorption and fluorescence properties in the Barataria Basin,Louisiana,USA

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Journal of Environmental Sciences 2010年第10期22卷 1481-1490页

作者： Shatrughan Singh Eurico D'Sa Erick Swenson department of oceanography and Coastal Sciences Louisiana State University

Absorption and fluorescence properties of chromophoric dissolved organic matter （CDOM） along a 124 km transect in the Barataria Basin, a large estuary located in Louisiana, USA, were investigated during high and low flow periods of the Mississippi River in the spring and winter of 2008-2009. Mean CDOM absorption at 355 nm from the marine to the freshwater end member stations ranged from （3.25 ± 0.56） to （20.76 ± 2.43） m^-1 for the three month high flow period whereas it varied from （1.48 ± 1.08） to （25.45 ± 7.03） m^-1 for the same stations during low flow period. Corresponding salinity values at these stations indicated the influence of river and shelf exchanges in the lower basin and precipitation and runoff in the upper basin. An inverse relationship of CDOM absorbance and fluorescence with salinity observed in the basin could he a useful indicator of salinity. CDOM fluorescence also varied over a large range showing an approximately 8 to 12-fold increase between the marine and freshwater end members for the two flow seasons. Excitation-emission matrix spectral plots indicated the presence of various fluorescence components with highest being the A-peak, lowest the T-peak, and the C and M-peaks showing similar trends along the transect. During low flow season the A/C ratio were well correlated with station locations indicating increased terrestrial influence towards the upper basin. CDOM absorption and fluorescence at 355 nm were highly correlated and independent of CDOM sources suggesting that fluorescence could be used to characterize CDOM in the basin.

关键词： Barataria Basin chromophoric dissolved organic matter CDOM fluorescence excitation-emission matrix

A growth model for a hyalid amphipod Hyale perieri in the coastal water of Alexandria(Egypt)

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Acta Oceanologica Sinica 2003年第2期22卷 221-232页

作者： Zakaria H.Y Dowidar N.M. El-Komi M.M. Atta M.M. National Institute of oceanography and Fisheries AlexandriaEgypt.Department of OceanographyFaculty of ScienceAlexandria UniversityEgyptNational Institute of Oceanography and FisheriesAlexandriaEgypt.Department of OceanographyFaculty of ScienceAlexandria UniversityEgypt

The growth rate of the hyalid amphipod Hyale perieri was studied on the bases of Ikeda'sgrowth model which is based on the inter moult period (IP) and moult increament (△BL). To apply this approach, laboratory experiments were carried out at three temperatures regimes (15℃, 20℃, 25℃ ) to gain accurate data of IP and BL. The total number of specimens used in this study was 86 at 15℃ , 24 at 20℃ and 70 at 25℃. The number of flagellar segments of both antennae of the Hyale perieri could not be used as an index of growth (instar criterion). The obtained results indicated that, the predicted IP of the specimens was inversely related to temperature and in good agreement with the observed values at the experimental temperatures. IP data obtained from laboratory-reared specimes are combined with ABL data to establish a growth model for Hyale perieri from its release from the mar-supium (1.64 mm BL ) to the maximum size (12.67 mm BL) as a function of temperature. The maximum numbers of consecutive moults recorded during the experiment were 13 moults (14 instar) at 15℃, 14 moults (15 instar) at 20℃ and 12 moults (13 instar) at 25℃ . The predicted life span for BL = 12.67 mm (moult 13) was 203.82 d at 15t, for BL = 11.75 mm (moult 14) was 138.94 d at 20℃ and for BL = 8.65 mm (moult 12) was 75.40 d at 25℃ respectively, thus confirming that the life span of the species is inversely proportional to temperature. Within the experimental temperatures tested, the optimum temperature for the growth of the species was 20℃.

关键词： growth model inter moult period and moult increament hyalid amphipod Hyale perieri coastal water of Alexandria

Evaluation of Haney-Type Surface ThermalBoundary Conditions Using a CoupledAtmosphere and Ocean Model

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Advances in Atmospheric Sciences 2001年第3期18卷 355-375页

作者： Peter C. Chu 陈玉春吕世华 department of oceanography Naval Postgraduate School

A coupled atmosphere-ocean model developed at the Institute for Space Studies at NASA Goddard Space Flight Center (Russell et al., 1995) was used to verify the validity of Haney-type surface thermal boundary condition, which linearly connects net downward surface heat fluxQ to air/sea temperature difference ΔT by a relaxation coefficientk. The model was initiated from the National Centers for Environmental Prediction (NCEP) atmospheric observations for 1 December 1977, and from the National Ocean Data Center (NODC) global climatological mean December temperature and salinity fields at 1°x 1° resolution. The time step is 7.5 minutes. We integrated the model for 450 days and obtained a complete model-generated global data set of daily mean downward net surface fluxQ, surface air temperatureT A, and sea surface temperatureT O. Then, we calculated the cross-correlation coefficients (CCC) betweenQ and ΔT. The ensemble mean CCC fields show (a) no correlation betweenQ and ΔT in the equatiorial regions, and (b) evident correlation (CCC≥0.7) betweenQ and ΔT in the middle and high latitudes. Additionally, we did the variance analysis and found that whenk=120 W m?2K?1, the two standard deviations, σQ and σκδT , are quite close in the middle and high latitudes. These results agree quite well with a previous research (Chu et al., 1998) on analyzing the NCEP re-analyzed surface data, except that a smaller value ofk (80 W m?2K?1) was found in the previous study. Key words Air-sea coupled system - Ocean surface fluxes - Surface thermal boundary condition

关键词： Air-sea coupled system Ocean surface fluxes Surface thermal boundary condition