Hao Wei

Tianjin University | tju · School of marine Science and Technology

In the southern Yellow Sea (SYS) there are temperature and salinity inversions associated with the presence of middepth low temperature and salinity water. Many questions regarding with the inversions, such as the seasonal variation and transformation mechanism, still remain unexplained. In this study, based on hydrographic measurements obtain from...

Open water in ice-covered oceans is an essential condition for shipping and resource exploitation. We investigate the interannual and spatial variations of the open water onset time in the Kara Sea (KS) and the underlying mechanisms through analyzing satellite-based observations and model simulation results. The empirical orthogonal function (EOF)...

Quantifying the flux of dissolved inorganic carbon (DIC) from the Chukchi shelf to the deep ocean (i.e., the continental shelf pump) is of great significance for understanding the carbon cycle and ocean acidification in the changing Arctic Ocean. Using a coupled ocean‐sea ice‐biogeochemical model, this study shows that the Pacific inflow drives the...

The Bohai Sea (BS) has been experiencing prominent deoxygenation in recent years that forms a typically coastal oxygen depleted region in summer. A three-dimensional coupled physical-biogeochemical model was used in this study to investigate temporal variations of the two separately-developing oxygen depleted zones in the BS. Comparison with observ...

Shedding light on the response of oceanic dimethyl sulfide flux (FDMS) on the sea shelf to multi‐pressures (intensified terrigenous nutrient inputs and climate change) is of great importance for regional aerosol budget. Here, we designed 4‐group experiments in scenario (the 1980s, 2010s, 2050s, and 2090s) for the Yellow and East China seas (YECS) b...

Several Chinese marine satellites have been launched in recent years. Monitoring sea ice and the ocean in the Arctic is of great importance for climate research. Sea ice in the Arctic has changed rapidly during the past few decades with respect to the extent and thickness. In this study, we applied combined passive and active microwave data from th...

The absorption spectral slope, S 275–295 , is an optical metric frequently employed for characterizing chromophoric dissolved organic matter (CDOM). We collected CDOM absorption ( a CDOM ) and fluorescence spectra from the oligotrophic offshore South China Sea to identify the major determinant of S 275–295 and to explore the potential of S 275–295...

Deep learning has been acknowledged as an increasingly important technology for ENSO forecasts. The most cutting-edge deep learning algorithm is developed based on Convolutional Neural Network (CNN), which can achieve a multi-year (about 17-month-lead) forecast and has conquered the ‘spring forecast barrier’ problem. However, this group of methods...

Mixing induced by oceanic mesoscale eddies can affect tracer distributions in the ocean and thus modulate the evolution of the physical and biochemical marine system. In the context of global warming, regionally different trends in eddy mixing could exist. Motivated by this hypothesis, we quantified the trend in surface eddy diffusivity, a metric w...

Existing research has proven the increase in sea surface temperature (SST) due to global warming. However, the sea bottom temperature (SBT) may exhibit different characteristics in various regional seas. The East China Shelf Seas (ECSSs), which are important shelf seas in the Western Pacific, hold ecological significance when analyzing their SBT va...

As temperature is regarded as a significant environmental factor affecting the intensity and frequency of jellyfish blooms, the projection of jellyfish peak biomass variation under global warming becomes essential for disaster prevention and mitigation on long-term time scales. The jellyfish Aurelia coerulea is distributed in worldwide oceans, part...

The spatial distribution and seasonal variation of near-inertial kinetic energy (NIKE) in the upper Ross Sea (RS) are examined using the 1/4° NEMO3.6-LIM3 sea ice physical–biological coupled model. The annual-mean surface and mixed layer-integrated NIKE have large values at the shelf break around Iselin Bank and the northeast area outside the conti...

Mesoscale eddies, ubiquitous in the global ocean, play a key role in the climate system by stirring and mixing key tracers. Estimating, understanding, and predicting eddy diffusivity is of great significance for designing suitable eddy parameterization schemes for coarse-resolution climate models. This is because climate model results are sensitive...

The seasonal species succession of phytoplankton from Phaeocystis antarctica to diatoms in the Ross Ice Shelf Polynya (RISP) plays a fundamental role in food webs and ecosystem functioning. Previous studies have revealed that this seasonal succession is affected by differences in light, iron demand, aggregation, and subsequent sinking between these...

High-frequency measurements of tides, waves, and turbulence were made using the bottom-mounted tripod equipped with the Nortek 6-MHz acoustic Doppler velocimetry during 20–23 February 2016 (winter) and 12–26 June 2017 (summer) in Heini Bay, Yellow Sea. The synchro-squeezed wavelet transform was applied for wave-turbulence decomposition, and an iter...

The Changjiang nutrient inputs serve as an important nutrient source for Chinese coastal waters. Its nutrient flux into the estuary has increased significantly over recent several decades, which may affect regional primary production and the sulfur cycle. Using a well-validated three-dimensional biophysical and geochemical model, we quantified the...

Pycnocline mixing lies at the heart of seasonally stratified shelf sea systems, regulating vertical exchange of momentum, mass, heat, and biogeochemical constituents. Based on microstructure measurements in the summer of 2013 and 2017, here we report on the widespread occurrence of intensified pycnocline turbulence in the summer stratified Yellow S...

Recent strengthening and westward movement of the Beaufort Gyre (BG), along with the rapid retreat of Arctic sea ice creates a new hotspot for investigating ecosystem responses to environmental changes over the Chukchi Borderland. As an important basis for primary production, nutrient variation and its controls in this hotspot region require to be...

With the demand of global carbon sink increase, the Arctic Ocean is expected as a major potential carbon sink after the retreating of sea ice. The Pacific Arctic Region, characterized with the high carbon fixation and large carbon flux into the deep-ocean for sequestration in the Chukchi Sea and adjacent waters, makes substantial contributions to c...

This study examines the characteristics, statistics, and mixing effects of internal solitary waves (ISWs) observed in the northern Yellow Sea (YS) during the summers of 2018 and 2019. The mooring stations are located between offshore islands with rough topographic features. Throughout the observation period, the ISWs with vertical displacements of...

Deep learning has been acknowledged as an increasingly important technology for ENSO forecasts. The most cutting-edge deep learning algorithm is developed based on Convolutional Neural Network (CNN), which can achieve a multi-year (about 17-month-lead) forecast and has conquered the ‘spring forecast barrier’ problem. However, this group of methods...

Jellyfish blooms have become a marine environmental issue with detrimental effects on marine ecosystems around the world. The jellyfish Aurelia aurita is one of dominant species of blooms worldwide and also in the Bohai and Yellow Seas (BYSs) of China. To investigate population dynamics and controlling factors on population biomass, a complex popul...

Based on microstructure measurements from a repeated sampling station southwest of the Jeju Island during summer, we studied the hydrography, pycnocline turbulence, and vertical salt flux in the Changjiang Diluted Water (CDW). The water column was well stratified with the CDW occupied the surface ~20 m. Most of the large turbulent kinetic energy di...

Results of coarse‐resolution climate models are sensitive to the specification of ocean eddy mixing coefficients. Therefore, it is important to estimate, rationalize and predict eddy diffusivities. Here, we estimate the seasonal variability of surface eddy diffusivities in the Kuroshio Extension region using numerical particles advected by a submes...

We investigate the spatio-temporal characteristics of the austral spring Ross Ice Shelf Polynya (RISP) and its relationship with atmospheric circulation anomalies based on the sea ice concentration data from the National Snow and Ice Data Center (NSIDC) and the ERA5 reanalysis data. The RISP area series is derived by choosing 25% sea ice concentrat...

Internal tides (ITs) represent one of the major energy sources available for small‐scale mixing in the ocean. Here, the energy pathway associated with ITs is examined based on measurements obtained at the East China Sea shelf slope. We reveal that after the occurrence of parametric subharmonic instability (PSI), energy can be further transferred fr...

Satellite records show that the extent and thickness of sea ice in the Arctic Ocean have significantly decreased since the early 1970s. The prediction of sea ice is highly important, but accurate simulation of sea ice variations remains highly challenging. For improving model performance, sensitivity experiments were conducted using the coupled oce...

Understanding how environmental factors impact the interannual variation in scallop growth and subsequently developing an easily obtained parameter to indicate this variation could provide a scientific basis for optimizing their aquaculture. In this study, we have set a growth scenario of uniformly sowed scallops of the same initial size in the Cha...

A coupled physical-biogeochemical model is used to investigate the seasonal evolution and controlling factors of oxygen depletion in the Bohai Sea (BS). Comparisons show that the model reproduces observed spatiotemporal variations of important physical and biogeochemical variables well. Bottom oxygen in the BS shows an annual cycle with significant...

Thermocline shear (i.e., velocity shear in the thermocline) lies at the heart of stratified shelf sea systems, regulating the vertical mixing and transport of mass and biogeochemical constituents. Based on year‐long moored ADCP measurements in the southern Yellow Sea (YS), the baroclinic kinetic energy and thermocline shear are investigated in this...

The summertime M2 internal tide in the northern Yellow Sea is investigated with moored current meter observations and numerical current model results. The hydrodynamic model, which is implemented from the Regional Ocean Model System (ROMS) with 1 km horizontal resolution, is capable of resolving the internal tidal dynamics and the results are valid...

The expansion of dissolved inorganic carbon (DIC)-rich water carried by the Pacific inflow creates a DIC maximum layer and exerts important influences on ocean acidification in the subsurface Arctic Ocean. This study analyzed shifts in the DIC distribution of the subsurface Arctic Ocean during 1998–2015 through hindcast simulation using a three-dim...

Identifying the main factors on spatial differences in net growth rate of Yesso scallop (Patinopecten yessoensis) in culture system is the key to effective aquaculture management and development. Coupling a 3D ecosystem model (ROMS-CoSiNE) with a dynamic energy budget model for scallops, a Yesso scallop culture ecosystem (YeSCE) model was establish...

Understanding the responses of air‐sea carbon dioxide (CO2) flux to rapid environmental changes in the highly productive Chukchi Sea is of great significance for the climate prediction in the Arctic Ocean. Through analyzing the 1998–2015 hindcast simulation of a coupled ocean–sea ice–biogeochemical model, this study identifies that the key factors...

The melting of sea ice affects the ocean heat absorption in the form of positive feedback, and plays an important role in the changes of the Arctic environment and economic activities in the Arctic region. Based on the daily sea ice concentration data of the Arctic Ocean from 1979 to 2018, the estimation method of sea ice retreat onset dates in the...

Persistent high primary production during the growing season in the Chukchi Sea (Arctic Ocean) plays a key role in maintaining an efficient biological carbon pump and diverse Arctic ecosystem. We used a three-dimensional ocean-sea ice-biogeochemical model to simulate monthly averaged net primary production from 1998 to 2015. The results show that t...

We developed a dimethylsulfide (DMS) module coupled to an ecological dynamics model studying the annual DMS cycle of the Yellow and East China seas (YECS). The model results showed that surface DMS concentrations ([DMS]) peaked in August along the coast, and there exhibited several DMS peaks offshore annually. In addition, surface [DMS] were higher...

The nutrient flux through Bering Strait has significant impacts on the biomass and community composition of phytoplankton in the western Arctic Ocean. Based on a three-dimensional ocean-sea ice-biogeochemical model, the hindcast simulations from 1998 to 2015 suggest that the nitrate flux through Bering Strait reaches the peak during February–May (~...

In the deep central part of the Bohai Sea off the coast of northern China, long-term observations show significantly lower dissolved oxygen (DO) concentration near the bottom in summer during 2006–2018 than during 1978–2005. The decrease in bottom DO is closely linked to changes in phytoplankton community driven by nutrient structure changes in the...

The sea ice conditions in the Kara Sea have important impacts on Arctic shipping, oil and gas production, and marine environmental changes. In this study, sea ice coverage (CR) less than 30% is considered as open water, its onset and end dates are defined as Topen and Tclose, respectively. The sea ice melt onset (Tmelt) is defined as the date when...

To evaluate the effects of the Hongyanhe Nuclear Power Plant on the zooplankton community in the surrounding seawater during summer, multiple environmental factors and zooplankton distribution along the east coast of Liaodong Bay were investigated in the summer of 2017. In particular, the influences of seawater temperature, salinity, and chlorophyl...

This study reveals that the yearday of open‐water onset (topen) in Bering Strait can be predicted with a lead time of about 4 months using a regression equation topen = 37.45CCN + 125.2 (in Julian days), with an averaged absolute error of 5 days and the maximum error of 12 days, where CCN is the ice concentration averaged from 16th January to 15th...

Four events of distinctly low summer ice coverage in the Beaufort Sea, in 1998, 2008, 2012 and 2016, have been identified from satellite observed concentration between 1979-2017. Previous studies have revealed that these 4 minima were impacted by preconditioning of the ice cover, and specifically the 1998 event was preconditioned toward thinner ice...

Turbulent microstructure and nitrate measurements from one repeated sampling station and two transects were analyzed focusing on the internal-wave (IW) induced turbulence and vertical nitrate flux adjacent to the Changjiang Estuary during fall. The repeated sampling station has a subsurface nitrate maximum zone locating within the stratified interi...

Based on mooring observations carried out in the southern Yellow Sea during late summer 2017, this study focuses on the characteristics of the internal tide-induced turbulent mixing and the influences on the vertical transport of nitrates. We observe clear semidiurnal pycnocline displacements with an amplitude of ∼3.5 m during 25 h. The baroclinic...

The Bohai and Yellow Seas (BYSs) are the marginal seas in the Northwestern Pacific region. Consistent with the general trend of global warming, the BYSs are also changing rapidly which include the change of sea surface temperature (SST), water masses and sea level etc. These parameters are very sensitive to the global warming due to the shallow wat...

Rapid changes in the near-bottom water temperature are important environmental factors that can significantly affect the growth and development of species in the bottom culture. The object of this research is to investigate the mechanism causing these rapid changes within a bottom culture area near the Zhangzi Island. The hydrographic transects obs...

Plain Language Summary The production, consumption, and transformation of dissolved organic matter (DOM) in the ocean play a key role in climate change, since the oceanic DOM stock in terms of carbon is similar to the amount of atmospheric CO2. The majority of oceanic DOM is contained in the deep ocean and resists bacterial degradation, which allow...

Based on measurements from an observing mooring system, the observational evidence of parametric subharmonic instability (PSI) that transfers energy from semidiurnal internal tides (ITs) to the subharmonic waves at the East China Sea continental shelf slope is presented for the first time. Although the mooring station is quite close to the energeti...

Distribution and variation of tidal front in coastal seas are mainly affected by net heat fluxes, wind friction, tide mixing, and buoyancy advection. Based on the observation in the eastern Liaodong Bay in July and August 2017 and the results obtained from ROMS (Regional Ocean Model System), we use the Stigebrandt formula with the effect of buoyanc...

Based on the repeated short-term shipboard Acoustic Doppler Current Profiler (ADCP) surveys of three sections around the coastal area of Hongyanhe Nuclear Power Station, the L-curve method was used to separate tidal and residual current. The relationship between the movement of water masses and the direction of residual currents was analyzed and th...

This study focused on the bloom-developing process of the giant jellyfish, Nemopilema nomurai, on phyto-plankton and microzooplankton communities. Two repeated field observations on the jellyfish bloom were conducted in June 2012 and 2014 in the southern Yellow Sea where blooms of N. nomurai were frequently observed. We demonstrated that the bloom was...

High‐frequency measurements of waves, currents, and turbulence were made using the bottom‐mounted tripod equipped with the Nortek 6‐MHz acoustic Doppler velocimetry at eight mooring stations in the East China Shelf Seas. The observational data are analyzed to estimate the bottom drag coefficient and also the contributions from currents and waves. V...

High-frequency measurements of waves, currents and turbulence were made using the bottom-mounted tripod equipped with the Nortek 6 MHz Acoustic Doppler Velocimetry at 8 mooring stations in the East China Shelf Seas. The observational data are analyzed to estimate the bottom drag coefficient, and also the contributions from currents and waves. V...

Based on hindcast simulation of a fine resolution ocean-sea ice model (NAPA1/12), the seasonal varia�tions of the Pacific Summer Water (PSW) over the northwestern Chukchi shelf, the eastern Chukchi slope and the Canadian Basin are evaluated. The path of PSW in the Arctic Ocean is also analyzed. Results indi�cate that: 1) Over the northwestern shelf...

The currents of the northern shelf of the Yellow Sea are investigated using observations of current and hydrography and numerical current model results. The Regional Ocean Model System (ROMS) with a horizontal resolution about 1km is implemented for the Yellow Sea and the Bohai Sea, and the results are produced for the year 2014 and 2015. Observati...

Coupled ocean and sea-ice models, developed based on Version 3.6 of the Nucleus for European Model�ling of the Ocean (NEMO), with the sea-ice component being Version 3 of Louvain-la-Neuve Sea Ice Model (LIM), are applied for hindcast simulations covering the North Atlantic-North Pacific-Arctic Oceans (NAPA). The two model configurations, NAPA1/4 an...

Eco-dynamics of marine plankton are remarkably sensitive to changes in their environments. The Arctic Ocean is undergoing rapid environmental changes as the global climate change intensifies. Understanding the sea�sonal distribution and variation of low-trophic plankton is a prerequisite for exploring the response of ecosystem to changing environme...

The dynamics of the subinertial response when a typhoon propagates over the ocean with a sloping bottom topography is investigated by carrying out a set of idealized numerical experiments. At least two different topographic Rossby waves (TRWs) are identified at the same along-slope wavenumber and two different subinertial frequencies in the wavenum...

When the Haiyang-2B (HY-2B) was launched into space to form a star network with the Haiyang-2B (HY-2A), it provided new data sources for the sea ice research of the Earth’s polar regions. The ability of altimeter echoes to distinguish sea ice and sea water is usable in operational ice charting. In this research study, the level 1B (L1B) data of HY-...

This study investigated the linkage between winter temperature in the Yellow Sea (YS), China, and atmospheric indices and established this linkage through statistical models. The water temperature was obtained through hindcast simulation using a global–regional nested ocean model for the period of 1958–2007. The interannual variations of the simula...

Ocean surface current (or ocean flow) visualization plays a significant role in the understanding of dynamical processes of ocean. It has been a hot research topic in both computer science and oceanography. Ocean surface current is a turbulent flow field mixing of multi-scale ocean dynamics such as large-scale ocean circulations (\(100\,\hbox {km}\...

High-frequency measurements of wind, waves, tides, suspended sediment concentration (SSC), and turbulence were made using an autonomous meteorological station and optical and acoustic instruments over 34 days during January 20–February 23, 2016, in Heini Bay, Yellow Sea. The responses of SSC on different dynamic processes are analyzed by decomposin...

Although various numerical experiments have been carried out to investigate the cascade of internal tide energy associated with parametric subharmonic instability (PSI), most of them assume idealized oceanic situations, ignoring the existence of background relative vorticity (ζ ). Here we show, for the first time, that the existence of ζ can signif...

During mid-May to early June 2016, a cold eddy and a warm eddy were captured on the continental slope of the northern South China Sea by the in situ measurements. A salty lens-shaped water mass in the subsurface layer existed in these two detected eddies, which indicated they had a Kuroshio water origin. The trajectories of the observed eddies from...

近年来，利用 ADCP 等设备来观测浅海悬沙动力过程成为了研究热点。本 研究组自 2005 年开始了底边界动力过程与悬沙运动关系的研究，并自主研发了 多种海床基观测平台，成功应用于中国近海 10 余年。

本发明涉及一种基于水压力反演海浪波高与周期的方法，包括：用水压式波高仪测量得到水下压力强度；得到水压力强度时间序列数据；通过对水压力强度时间序列数据进行傅里叶变换得到压力频谱；考虑水压力的线性趋势变化和压力波在深度上、水层过滤作用的衰减，计算出表面波浪的压力校正系数，对水压力进行校正；依据谱矩法或者对压力频谱进行傅里叶反变换利用上跨零点分波法，反演出高时空分辨率的海浪波高与周期。

本发明涉及一种基于声学反演悬浮颗粒物浓度的方法，包括：利用声学多普勒海流剖面仪接收水中散射体的后散射信号得到回声强度；根据声呐方程，考虑声波的几何衰减和吸收衰减对回声强度进行校正，得到体积后向散射强度；根据校正后得到的体积后向散射强度，依据瑞利散射原理,最终反演出高时空分辨率的悬浮物颗粒物浓度。本发明可以得到较为精确的悬浮颗粒物浓度。

本发明涉及一种原位测定海洋浮游生物种类与生物量的装置，包括以下三部分：数据采集器、数据管理系统和供电系统，数据采集器包括：原位荧光检测仪、基因芯片、现场激光粒度分析仪；原位荧光检测仪配置有荧光探头，通过荧光测定现场叶绿素浓度，并由叶绿素浓度求浮游植物生物量；基因芯片搭载有DNA分子探针，通过DNA分子探针探测浮游生物的分子序列，确定浮游生物的种类和数量；现场激光粒度分析仪运用基于光学后向散射的粒径测量方法，通过悬浮物粒径谱分析海水中的悬浮物颗粒物的粒级大小和浓度

本发明公开了一种走航ADCP数据质量分析与再处理系统，由信息数据库、可视化数据处理终端、走航ADCP数据再处理功能模块组成；信息数据库存储走航ADCP测定的流速数据、底跟踪数据、GPS经纬度数据、AVISO卫星高度计所测地转流数据、其它定点流速观测数据、高分辨率全球潮模式模拟的潮流数据；可视化数据处理终端具有数据分析和绘图功能；走航ADCP数据再处理功能模块包括浮游生物生态模块、悬浮物研究模块以及谱分析模块。本发明具有直观、简洁明了、易操作、针对性强的特点，可以克服目前走航ADCP数据处理工作中难度大、效率低、错误多和数据质量水平不高的缺点。

本发明涉及一种原位测量海洋湍流与悬浮物的观测装置，包括固定仪器支架(2)，防护仪器碰撞支架(3)，支撑支架(4)，三角底座支架(5)，普通圆盘(6)，铅圆盘(7)和尖角(8)，其中，固定仪器支架(2)固定在防护仪器碰撞支架(3)及支撑支架(4)内，支撑支架(4)固定连接在防护仪器碰撞支架(3)的下部，包括三个支杆，支杆的下部通过三角底座支架(5)相互固定，架防护仪器碰撞支架(3)的下部，每个支杆的下部均固定有较大的普通圆盘和位于普通圆盘下方的较小的配重圆盘，在每个配重圆盘的下部固定有尖角(8)。

本发明涉及一种走航测量海水流速的观测装置，包括三部分：可调节长度的杆件组、分别与其上部和下部相连的与船连接的构件和搭载声学多普勒流速剖面仪ADCP的构件；与船相连的构件包括与船连接夹板，其两侧均设置有预留开孔的加劲肋，一侧用来扣在船舷上，另一侧与可调节长度的杆件组之间用杆件套筒相连；搭载ADCP的构件的上部通过设置有法兰加劲肋的杆件连接法兰与可调节长度的杆件组相连，下部与设置有加劲肋的连接ADCP的法兰相连，搭载ADCP的构件上预留安装ADCP电缆的穿孔。

Based on a coupled physical-biogeochemical model of the Yellow and East China Seas (YECS), the influence of biological activity on the seasonal variation of the air–sea CO2 flux is evaluated. The solution of a sensitivity experiment that excludes biological activity is compared with that of a reference experiment that includes the full processes. T...

Since the beginning of the 21st century, Chinese coastal seas have often suffered from jellyfish blooms, which may relate to global climate change and human activity. There are some economically important Chinese sea areas for people such as beaches for tourism, the water intake area of a power plant, and other industry facilities, where frequent j...

Tidal straining describes the straining effect induced by the vertical shear of oscillatory tidal currents that act on horizontal density gradients. It tends to create tidal periodic stratification and modulate the turbulence in the bottom boundary layer (BBL). Here, we present observations of current, hydrology and turbulence obtained at two moori...

This study evaluates the contribution of sediment oxygen demand (SOD) to hypoxia development off the Changjiang Estuary based on SOD measurements from onboard chamber incubations and numerical experiments. Onboard core incubations were conducted for samples collected from four stations in the Yellow Sea (YS) and the East China Sea (ECS) during crui...

A nested model for the simulation of tides and storm surges in the Bohai Sea, China, has been developed based on the three-dimensional finite-volume coastal ocean model. The larger domain covers the entire Yellow Sea and Bohai Sea with a horizontal resolution of ~10 km, and the smaller domain focuses on the Bohai Sea with a fine resolution up to ~3...

Identifying particle characteristics through in situ observations can be beneficial for understanding local sediment dynamics. This study analyzed the suspended particulate material (SPM) characteristics in the Yellow Sea and East China Sea, as well as the hydrological structure and chlorophyll a (Chl a) concentration in summer during a cruise cond...

Based on observational data from ten cruises carried out in 2012 and 2013, the distribution of dissolved oxygen (DO) and hypoxia (DO < 2.0 mg L−1) evolution in waters adjacent to the Changjiang estuary are studied. The linkage between summer hypoxia and hydrodynamic conditions is explored. The results suggest that hypoxia frequently occurred from J...