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The distribution and inter-annual variation of water masses on the Bering Sea shelf in summer

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Acta Oceanologica Sinica 2016年第11期35卷 59-67页

作者： LIU Na LIN Lina WANG Yingjie CHEN Hongxia HE Yan The first institute of oceanography State Oceanic Administration

On the basis of the CTD data obtained within the Bering Sea shelf by the Second to Sixth Chinese National Arctic Research Expedition in the summers of 2003, 2008, 2010, 2012 and 2014, the classification and interannual variation of water masses on the central Bering Sea shelf and the northern Bering Sea shelf are analyzed. The results indicate that there are both connection and difference between two regions in hydrological features. On the central Bering Sea shelf, there are mainly four types of water masses distribute orderly from the slope to the coast of Alaska： Bering Slope Current Water（BSCW）, MW（Mixed Water）, Bering Shelf Water（BSW） and Alaska Coastal Water（ACW）. In summer, BSW can be divided into Bering Shelf Surface Water（BSW_S） and Bering Shelf Cold Water（BSW_C）. On the northern Bering Sea shelf near the Bering Strait,it contains Anadyr Water（AW）, BSW and ACW from west to east. But the spatial-temporal features are also remarkable in each region. On the central shelf, the BSCW is saltiest and occupies the west of 177°W, which has the highest salinity in 2014. The BSW_C is the coldest water mass and warmest in 2014; the ACW is freshest and mainly occupies the east of 170°W, which has the highest temperature and salinity in 2012. On the northern Bering Sea shelf near the Bering Strait, the AW is saltiest with temperature decreasing sharply compared with BSCW on the central shelf. In the process of moving northward to the Bering Strait, the AW demonstrates a trend of eastward expansion. The ACW is freshest but saltier than the ACW on the central shelf,which is usually located above the BSW and is saltiest in 2014. The BSW distributes between the AW and the ACW and coldest in 2012, but the cold water of the BSW_C on the central shelf, whose temperature less than 0°C, does not exist on the northern shelf. Although there are so many changes, the respond to a climate change is synchronized in the both regions, which can be divided into the warm years（2003 and 201

关键词： Bering Sea shelf water mass inter-annual variation Chinese National Arctic Research Expedition

Effects of Tamarisk shrub on physicochemical properties of soil in coastal wetland of the Bohai Sea

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Acta Oceanologica Sinica 2016年第5期35卷 106-112页

作者： HE Xiuping WANG Baodong XIE Linping XIN Ming WANG Wei WANG Zicheng ZHANG Wenquan WEI Qinsheng first institute of oceanography State Oceanic Administration

There are many different and even controversial results concerning the effects of Tamarisk on the physicochemical properties of soil. A year-round monitoring of soil salinity, p H and moisture is conducted beneath the Tamarisk shrub in a coastal wetland in the Bohai Sea in China, to ascertain the effects of Tamarisk on the physicochemical properties of soil in coastal wetland. Compared with the control area, the soil moisture content is lower around the area of the taproot when there is less precipitation in the growing season because of water consumption by Tamarisk shrub. However, the soil moisture content is higher around the taproot when there is more precipitation in the growing season or in the non-growing period because of water conservation by the rhizosphere. The absorption of salt by the Tamarisk shrub reduces the soil salinity temporarily, but eventually salt returns to the soil by the leaching of salt on leaves by rainfall or by fallen leaves. The annual average soil moisture content beneath the Tamarisk shrub is lower than the control area by only 6.4%, indicating that the Tamarisk shrub has little effect on drought or water conservation in soils in the temperate coastal wetland with moderate annual precipitation. The annual average salinity beneath the Tamarisk shrub is 18% greater than that of the control area, indicating that Tamarisk does have an effect of rising soil salinity around Tamarisk shrubs. The soil p H value is as low as 7.3 in summer and as high as 10.2 in winter. The p H of soil near the taproot of the Tamarisk shrubs is one p H unit lower than that in the control area during the growing season. The difference in p H is less different from the control area in the non-growing season, indicating that the Tamarisk shrub does have the effect of reducing the alkalinity of soil in coastal wetland.

关键词： coastal wetland Tamarisk soil physicochemical parameter

A statistical analysis of mesoscale eddies in the Bay of Bengal from 22–year altimetry data

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Acta Oceanologica Sinica 2016年第11期35卷 16-27页

作者： CUI Wei YANG Jungang MA Yi The first institute of oceanography State Oceanic Administration

Eddy properties in the Bay of Bengal are studied from 22 a archiving, validation and interpretation of satellite oceanographic（AVISO） data using a sea level anomaly（SLA）-based eddy identification. A geographical distribution and an eddy polarity, an eddy lifetime and propagation distances, eddy origins and terminations,eddy propagation directions and trajectories, eddy kinetic properties, the evolution of eddy properties,seasonal and interannual variabilities of eddy activities are analyzed in this area. Eddies exist principally in the western Bay of Bengal and most of them propagate westward. The polarity distribution of eddies shows cyclones prefer to occur in the northwest and south of the Bay of Bengal, while anticyclones mainly occur in the east of the bay. Five hundred and sixty-five cyclones and 389 anticyclones with the lifetime that exceeds 30 d are detected during the 22 a period, and there is a preference for the cyclones for all lifetime and propagation distances. The kinetic properties of all observed eddies show the average amplitude of the cyclones is larger than that of the anticyclones, whereas that is opposite for average radius, and their average velocities are basically the same. Moreover, the evolution of eddies properties reveals that the eddies with a long lifetime that exceeds 90 d have a significant double-stage feature of the former 50 d growth period and the dying period after 50 d. For the seasonal variability of the eddies, the cyclones occur more often in spring while the anticyclones occur more often in summer. The analysis of long-lived eddy seasonal distributions shows that there is the obvious seasonal variation of the eddy activities in the Bay of Bengal. The interannual variability of an eddy number shows an obvious negative correlation with the EKE variation.

关键词： mesoscale eddy altimetry data Bay of Bengal eddy characteristics seasonal variabilit3 interannual variability

Analysis of multi-dimensional SAR for determining the thickness of thin sea ice in the Bohai Sea

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Chinese Journal of Oceanology and Limnology 2013年第3期31卷 681-698页

作者：张晰张杰孟俊敏苏腾飞 The first institute of oceanography State Oceanic Administration

Flat thin ice (<30 cm thick) is a common ice type in the Bohai Sea, China. Ice thickness detection is important to offshore exploration and marine transport in winter. Synthetic aperture radar (SAR) can be used to acquire sea ice data in all weather conditions, and it is a useful tool for monitoring sea ice conditions. In this paper, we combine a multi-layered sea ice electromagnetic (EM) scattering model with a sea ice thermodynamic model to assess the determination of the thickness of flat thin ice in the Bohai Sea using SAR at different frequencies, polarization, and incidence angles. Our modeling studies suggest that co-polarization backscattering coefficients and the co-polarized ratio can be used to retrieve the thickness of flat thin ice from C- and X-band SAR, while the co-polarized correlation coefficient can be used to retrieve flat thin ice thickness from L-, C-, and X-band SAR. Importantly, small or moderate incidence angles should be chosen to avoid the effect of speckle noise.

关键词： multi-dimensional SAR sea ice in the Bohai Sea flat thin ice thickness retrieval

The improved model of estimating global whitecap coverage based on satellite data

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Acta Oceanologica Sinica 2016年第5期35卷 66-72页

作者： REN Danqin HUA Feng YANG Yongzeng SUN Baonan first institute of oceanography State Oceanic Administration

The pro and con of whitecap parameterizations and a statistical wave breaking model are discussed. An improved model is derived by combining satellite-based parameterization and the wave breaking model. The appropriate constants for the general wave state are obtained by considering the breaking condition of the wave slope and fitting with the satellite-based parameterization. The result is close to the constants based on the whitecap data from Monahan. Comparing with satellite-based data and the original model＇s results, the improved model＇s results are consistent with satellite-based data and previous studies. The global seasonal distributions of the whitecap coverage averaged from 1998 to 2008 are presented. Spatial and seasonal features of the whitecap coverage are analyzed.

关键词： whitecap coverage statistical wave breaking model satellite-based parameterization

An ocean circulation model based on Eulerian forward-backward difference scheme and three-dimensional, primitive equations and its application in regional simulations

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Journal of Hydrodynamics 2014年第1期26卷 37-49页

作者：韩磊袁业立 institute of oceanography China Academy of Sciences first institute of oceanography State Oceanic Administration

A two-time-level, three-dimensional numerical ocean circulation model is established with a two-level, single-step Eulerian time-difference scheme. The mathematical model of the large-scale oceanic motions is based on the terrain-following coo-rdinated, Boussinesq, Reynolds-averaged primitive equations of ocean dynamics. A simple but very practical Eulerian forward-back-ward method is adopted to replace the most preferred leapfrog scheme as the time-difference method for both barotropic and barocli-nic modes. The forward-backward method is of the second order of accuracy, requires only once of the function evaluation per time step, and is free of the computational mode inherent in the three-level schemes. It is superior in many respects to the original leapfrog and Asselin-filtered leapfrog schemes in the practical use. The performance of the newly-built circulation model is tested by simula-ting a barotropic （tides in marginal seas of China） and a baroclinic phenomenon （seasonal evolution of the Yellow Sea Cold Water Mass）, respectively. The three-year time histories of four prognostic variables obtained by the POM model and the two-time-level model are compared in a regional simulation experiment for the northwest Pacific to further show the reliability of the two-level scheme circulation model.

关键词： forward-backward scheme ocean circulation model Yellow Sea Cold Water Mass

Hydrodynamical Basis for Interpreting the Features of a Kind of Ocean Objects on Synthetic Aperture Radar Images

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Chinese Physics Letters 1998年第12期15卷 931-933页

作者： YU Wei-dong HUA Feng JIN Mei-bing PAN Zeng-di YUAN Ye-li first institute of oceanography State Oceanic AdministrationQingdao 266003

A new hydrodynamical model interpreting the synthetic aperture radar(SAR)imaging of a kind of ocean objects is *** is based on the perturbation analysis of the wave height spectrum balance *** appropriate form of equilibrium wave height spectrum is deduced and then used to obtain the relative variation rate of the spectrum perturbation to its equilibrium *** variation rate reflects directly the features of a kind of ocean objects on the SAR images.

关键词： spectrum Synthetic equilibrium

Satellite retrieval of inherent optical properties in the turbid waters of the Yellow Sea and the East China Sea

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Chinese Optics Letters 2010年第8期8卷 721-725页

作者：崔廷伟张杰唐军武马毅青松 first institute of oceanography State Oceanic Administration National Satellite Ocean Application Service State Oceanic Administration

In situ-satellite match-ups of radiometric data are established in the turbid waters of the Yellow Sea and the East China Sea. Inherent optical properties （IOPs） are retrieved by match-up radiometric data and multi-band quasi-analytical algorithm （QAA）. By comparing in situ spectra-retrieved IOPs with the satellite ones of moderate resolution imaging spectroradiometer （MODIS） and medium resolution imaging spectrometer （MERIS）, the accuracy of satellite-derived IOPs is quantified. The median of the absolute percentage difference is found to be approximately 20% for the total absorption coefficient at（λ） at green and blue-green bands, and 30% for particulate material backscattering coefficient bbpλ throughout the visible bands. The spatial pattern and temporal variability of IOPs along the eastern coast of China are clarified based on satellite images and the QAA model.

关键词： Backscattering Coastal zones Radiometers Radiometry Satellite imagery Spectrometers

The effects of the non-breaking surface wave-induced vertical mixing on the forecast of tropical cyclone tracks

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Chinese Science Bulletin 2014年第24期59卷 3075-3084页

作者： Biao Zhao Fangli Qiao Guansuo Wang first institute of oceanography State Oceanic Administration

The Weather Research and Forecasting model(WRF)is configured for the region of(15°–41°N,105°–135°E),which covers the same area with the MASNUM(Key *** Science&Numerical Modeling,state oceanic administration)wave-tide-circulation coupled operational forecast *** numerical experiments are implemented to investigate the effects of the real-time forecasted sea surface temperature(SST)and the nonbreaking wave-induced vertical mixing(Bv)on the track forecast of all 33 tropical cyclones(TC)in the model domain area during 2008 and *** first experiment employs NCEP FNL(NCEP final analysis)SST as WRF’s bottom condition as the Control run,which is also the default setup of *** second and third experiments use real-time forecasted SST from the MASNUM forecast system with and without Bv,*** forecasted track results are compared with Japan Meteorological Agency’s best track *** 24-h forecast,the averaged TC position error of Experiment with Bv is reduced by 9%compared to the Control experiment,while the forecasted track error of Experiment without Bv is reduced by only2%compared to the Control *** the 48-h forecast,the averaged track errors are reduced by 10%and6%with Bv and without Bv compared to the Control experiment,*** results suggest that the real-time forecasted SST can improve the performance of WRF in forecasting TC track,and the Bv plays an important role in reducing the forecast error of TC ***,Bv can improve more on the track of stronger TC.

关键词：热带气旋路径预报垂直混合重点实验室 WRF模式实时预测面波数值试验最佳轨道