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An attention U-Net was proposed to reconstruct the missing chlorophyll-a concentration (Cchla) data. The U-Net is a lightweight full convolution neural network architecture consisting of an enccoder-decoder (i.e., down-sampling and up-sampling). The attention gates (AGs) were integrated into the U-Net. Training the U-Net with AGs could implicitly teach it to suppress irrelevant areas and highlight the salient features in the missing data areas, which would increase the network sensitivity and reconstruction accuracy. The neural network uses the satellite-derived Cchla anomalies and its variance as the input, and the reconstructed fields along with their variances as outputs. The trained network was applied to long-term daily MODIS/Aqua Cchla products in the Pearl River estuary (PRE) and adjacent continental shelf area. The model performance was evaluated by using an independent test dataset from both satellite-derived and in-situ measurements. The results showed that the proposed neural network not only had good performance in the reconstruction of valid pixels, but also provided a more reasonable reconstruction compared to the standard U-Net without AGs. This study provided a feasible method for the reconstruction task in the field of ocean color, which should be helpful in producing a creditable dataset to study the ecological effects of extreme weather conditions such as typhoons on the upper ocean in the PRE waters. Based on the reconstructed Cchla products, the footprints of the typhoons were studied. An increase in surface Cchla near the typhoons' track and a decrease in estuary were found. The composite results illustrated that the Cchla increases occurred for almost the entire area within a radius of 100 km. The time series analysis showed that the Cchla peak appeared on the fifth day after the typhoon's passage. [ABSTRACT FROM AUTHOR]

High-intensity focused ultrasound (HIFU) has been reported to be a minimally invasive effective method for the treatment of secondary hypersplenism. However, neither the short-term efficacy nor the indications and/or contraindications have been described in patients with cirrhosis. From October 2019 to May 2021, eleven cases of patients with cirrhotic secondary hypersplenism were enrolled. The blood counts, liver function tests and abdominal ultrasound and/or MRI scans of all patients were closely evaluated. Among these 11 patients, eight (72.7%) patients were classified as Child–Pugh A, and the other 3 (27.3%) patients were Child–Pugh B; Five (45%) patients were diagnosed with gallstone, including multiple small stones in 2 patients and single stone in 3 patients. HIFU was performed successfully in all 11 patients. After HIFU, hematologic parameters and liver function were significantly improved in all 11 patients (p < 0.05). The HIFU ablated volume to spleen volume rate was 35–61%. Complications were ecchymosis of the waist in 7 (63.3%) patients, ablated area pain in 3 (27.3%) patients, and choledocholithiasis in 2 (18.2%) patients with multiple small gallstones. All of them recovered smoothly without additional treatment except for 2 patients with choledocholithiasis recovered with risky endoscopic retrograde cholangiopancreatography (ERCP) treatment. This series suggested that HIFU is an effective and safe treatment for cirrhotic secondary hypersplenism in patients classified as Child–Pugh A or B. However, multiple small gallstones could be a relative contraindication for it. [ABSTRACT FROM AUTHOR]

The China‐France ocean satellite (CFOSAT) has obtained synchronized observations of sea winds and sea waves for the first time in the world, providing accurate data support for the study of swells. In this paper, the accuracy of key parameters and the wave spectrum of CFOSAT surface waves investigation and monitoring (SWIM) L2 data are analyzed and evaluated using a spatial‐temporal matching criterion. The accuracies of the significant wave height (SWH), spectrum peak period (Tp) and dominant azimuth (Azi) are 0.76 m, 2.89 s and −24.02°, respectively, in the coastal area of the South China Sea (SCS) and 0.30 m, 0.97 s and 13.02° in the offshore area of the SCS. Calculated based on CFOSAT SWIM data, the annual average SWH of mixed waves in the SCS is 1.47 m, and 80% of them are between 0.5 and 3 m. There are high value areas in the central, northeastern and southwestern parts of the SCS. The average annual SWH of swells is 0.93 m, and 99% of swells are less than 2 m. A high swell SWH also exists in the central part of the SCS. Plain Language Summary: Swells are an important marine resource. Due to their long propagation distance and fast propagation speed, they can effectively forecast storm surge. They also have large energy and good stability, which are conducive to acquisition and conversion, and they have become a new method for offshore power generation. China‐France ocean satellite provides a convenient means to observe waves and to verify the accuracy of wave parameters, which is an important step for wave detection. The South China Sea, with its vast sea area and abundant swell energy reserves, is an ideal area for offshore power generation. Understanding the distribution of swell energy in the South China Sea (SCS) provides an opportunity to explore a sustainable and reliable renewable energy source. The SCS is also important and significant to the development and utilization of swell energy and for the site selection of offshore power stations. Key Points: Precision valuation of surface waves investigation and monitoring L2 data such as significant wave height (SWH), spectrum peak period (Tp), dominant azimuth (Azi) were carried out and it was determined that the data were stableThe annual average SWH in the South China Sea is 1.47 m and 80% of them are between 0.5 and 3 mWind‐swell separation was carried out, and the distribution of swell SWH shows a high value in the central part of the South China Sea [ABSTRACT FROM AUTHOR]

The accurate initial background of the high heterogeneity of particle size distributions (PSDs) is crucial for modeling the carbon cycle across the continental shelf. However, the lack of field measurements and constraints on PSDs has made this task challenging. In particular, different power-law models have been used to fit field PSDs, which can introduce bias in the calculated PSD slopes (ξ s) and mislead subsequent biogeochemical modeling. This study analyzes the characteristics and variabilities of PSDs across the continental shelf of the northern South China Sea (NSCS) using field data and evaluates the stability of common power-law models for calculating ξ. The first-order variations of most regional PSDs follow the power-law distributions. However, the second-order variations of these PSDs lead to fluctuations in ξ values calculated by the different-reference-point power-law model, which lacks a correction parameter. A power-law model with a correction factor can be used to calculate ξ stably, regardless of the second-order variations of these PSDs. We recommend using this power-law model to calculate ξ , and it can be extended to describe other oceanic field PSDs. Our results also highlight the high spatial heterogeneity of ξ across the NSCS continental shelf, which should be considered in regional biogeochemical modeling. Our study provides important insights into which power-law model can be used to derive stable and comparable ξ -field datasets for the purpose of initializing and constraining of biogeochemical models. • The first-order variations of most PSDs across the continental shelf of the northern South China Sea follow the power-law distributions. • The power-law model with a correction parameter is recommended for calculation of particle-size-distribution slope (ξ). • The spatial heterogeneity of ξ should not be ignored in the study of the biogeochemical processes and modeling across the continental shelf of the northern South China Sea. [ABSTRACT FROM AUTHOR]

Accurate estimation of the near-surface chlorophyll-a (Chl-a) concentration in turbid estuaries via remote sensing is an ongoing challenge. Recently, with the successful launch of the third satellite of the China Ocean Colour Satellite Series, HY-1 C, equipped with the Coastal Zone Imager (CZI) with a 3-day revisit period and 50-m resolution in four bands, this study constructed a Chl-a inversion model via symbolic regression (SR) in the Pearl River Estuary (PRE) considering 60 in situ samples to explore the current ocean colour monitoring potential of the CZI. Compared to five state-of-the-art algorithms, the SR model attained a lower mean absolute percentage error (MAPE, 35.51%), mean absolute error (MAE, 1.56) and root-mean-square error (RMSE, 0.24). Additionally, the Chl-a spatial distributions determined with the SR model also better coincided with those determined with synchronous satellite products. The above results indicate that the SR model performed better than the five state-of-the-art models and could be effectively applied to turbid PRE waters. This research may provide a reference regarding the practicality and feasibility of the CZI in water environment monitoring in coastal and estuarial waters at a high temporal-spatial resolution. [ABSTRACT FROM AUTHOR]

The duration of a single satellite deployment is insufficient to detect long-term trends in phytoplankton biomass. By integrating data from different platforms, we quantified the phytoplankton trends in the South China Sea (SCS) from the early-to-mid 1980s to the present. We focused on winter data because the sea surface temperature (SST) in winter has been increasing over the past three decades. We included data from three different eras: (1) the Coastal Zone Colour Scanner (CZCS) period (1979–1983), (2) the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) period (1998–2002), and (3) the Moderate Resolution Imaging Spectroradiometer (MODIS) period (2010–2014). There was a decline in phytoplankton (approximately 0.15 mg m−3) over the entire SCS from the CZCS period to the SeaWiFS period. The largest reduction (over 0.3 mg m−3) occurred in the northern and western SCS. After the SeaWiFS period, the phytoplankton increased by approximately 0.05 mg m−3. The largest increase was observed to the west of Luzon Strait, extending towards the east coast of Hainan Island. The fluctuations in phytoplankton from the early-to-mid 1980s to the present were consistent with the variation in the wind field rather than with the continued increase in SST. The wind speed decreased from the CZCS period to the SeaWiFS period and increased from the SeaWiFS period to the MODIS period. Moreover, the nutrient variations induced by the mixed-layer depth also contributed to the fluctuations in phytoplankton. [ABSTRACT FROM AUTHOR]

An algorithm of the red-peak envelop area (PEA) near 700 nm was evaluated using in situ data during nine cruises in the Pearl River estuary and compared with other algorithms using the reflectance peak (RP) near 700 nm, including the fluorescence line height (FLH), maximum chlorophyll index (MCI), and MCI2 algorithms. Of all algorithms, the PEA algorithm presented the most accurate performance [ $R^{2}= 0.74$ , root-mean-square error RMSE = 0.12] and provided a more rational spatial distribution of phytoplankton blooms when both Sentinel 3 Ocean and Land Color Instrument (OLCI) and Hyperion data were used because the PEA integrates information from both the moving peak and the asymmetric curve on each side of the peak due to the high correlation relationship ($R^{2}= 0.7$) of chlorophyll and the ratio of the peak area between the left and right halves. Moreover, compared with other algorithms, the PEA algorithm developed using the Hyperion (higher spectral resolution) and OLCI band settings presented similar retrieval accuracies. These results demonstrated that the PEA algorithm is less dependent on the band settings, and the spectral band settings of OLCI from 650 to 750 nm are reasonable and can be used to detect phytoplankton blooms if the PEA algorithm is applied. The OLCI PEA algorithm was applied to determine the variations in phytoplankton blooms under the influences of strong precipitation events. The most obvious increases in chlorophyll concentration (from 20 to 30 mg $\text{m}^{-3}$) were observed in the middle river channel upstream of the Pearl River estuary after strong precipitation events. [ABSTRACT FROM AUTHOR]

To obtain dual active near-infrared (NIR) nanomaterial with strong absorption and emission properties, we report herein a novel precursor reactivity differentiation strategy, i.e., utilizing 1-octadecene (ODE)-Se having the ability to react with Ag salts much stronger and faster than ODE-thiourea, for single-step preparation of Ag2Se@Ag2S nanocrystals (NCs). With this strategy, we were able to synthesize high-quality Ag2Se@Ag2S NCs with both excellent NIR absorption and emission properties. Particularly, these nanocrystals possess a rather strong and sharp excitonic absorption peak with a full width at half maximum less than 70 nm and a maximum fluorescence quantum yield as high as 24.3%. Their appealing optical properties and structural features were founded to be highly dependent on the Se to S precursor ratio in the reaction solutions, owing to such a ratio exerting a direct influence on the core sizes and shell thicknesses of the as-formed NCs. Taking advantage of their remarkable NIR absorption properties, self-powered photoelectrochemical-type photodetectors based on the as-prepared Ag2Se@Ag2S NCs were successfully fabricated, which demonstrate a much better response performance and photostability in comparison with those based on Ag2Se NCs. [ABSTRACT FROM AUTHOR]

An anticyclonic eddy's periphery is characterized by large horizontal density gradients, strain and vertical velocity. In this paper we document the asymmetric distribution of phytoplankton around the periphery of anticyclonic eddies in the western South China Sea based on 432 eddies detected from satellite data. The high level of phytoplankton occurs consistently at the northwestern periphery of eddies, with a maximum positive chlorophyll anomaly greater than 0.01 mg m −3 . The asymmetric distribution of phytoplankton primarily tags the non-uniform surface velocity field varying from 0.15 m s −1 to 0.3 m s −1 along the eddy's periphery. The coastal boundary and off-coast jet may be the primary cause of the non-uniform flow. Associated with the non-uniform flow speed, the combined effects of the velocity convergence and steepened northwestern part of the eddies act to sharpen the density fronts and tend to result in an ageostrophic secondary circulation at the northwestern edge of the eddy. The upward component of the ageostrophic secondary circulation can enhance the nutrient flux into the euphotic layer, thereby increasing phytoplankton productivity. Anticyclonic eddy-induced ageostrophic secondary circulation appears to be an important mechanism for increasing phytoplankton productivity in the oligotrophic waters of the South China Sea. [ABSTRACT FROM AUTHOR]

The Finite Time Lyapunov Exponent technique is a highly effective way to visualize and analyze flow fields. Its ridges are referred to as Lagrangian Coherent Structures which reveal the transport barriers of fluid systems, or their hidden skeletons. This allows us to investigate the complex mesoscale and submesoscale ocean processes on a Lagrangian view. In this article, we use the Lagrangian technique to investigate one chlorophyll bloom event in the northeastern South China Sea and discuss the impact of horizontal transport on the distribution of surface chlorophyll. Our results demonstrate that horizontal transport barriers uncovered by Lagrangian Coherent Structures can shape the vortex and filament in a simple and distinct way. [ABSTRACT FROM PUBLISHER]

The present study aims to investigate the temporal variability of chromophoric dissolved organic matter through remote sensing and to determine its influence factors in the Pearl River Estuary. A medium resolution imaging spectrometer, chromophoric dissolved organic matter product was evaluated with in situ absorption coefficient (R2= 0.9605, RMS = 0.1672 and MRE = 0.3930). L2 daily products were then averaged into monthly data to analyze variability in the specified area from January 2003 to December 2009. Accumulated anomaly analysis and the wavelet analysis showed that the variability had a significant period of one year from 2003 to 2009, accompanied with 3 and 6 month periods in 2004 and 2008 separately. Cross wavelet transform was used to analyze the relationships between chromophoric dissolved organic matter and its influence factors including rainfall and phytoplankton in time frequency space. Relationships with salinity and light were also analyzed. It was found that photobleaching induces lower dissolved organic matter in summer even though there is greater discharge due to large rainfall intensity during this season. However, the anomalous strong precipitation may cause significantly higher findings in the study area. An example was a heavy flood caused by strong precipitation in 2008 induced higher findings for the period for less than half a year. [ABSTRACT FROM AUTHOR]

Seasonal and intraseasonal variability of surface chlorophyllaconcentration in the South China Sea is explored using the NASA standard Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) monthly and 8-day level-3 products from 1997 to 2007. The link between the seasonal and intraseasonal variability of the chlorophyll and physical forcing is revealed. Continuous wavelet transform indicates that chlorophyll in the South China Sea presents pronounced seasonal, as well as intraseasonal, variability. Chlorophyllavariability shows significant correlation with wind speed in all five sub-regions, while significant correlation with sea surface temperature only appears in the northern Sea. Intraseasonal variability of chlorophyll appears mainly in the winter, with spectral peaks around 32–64 days. It shows high commonalities for some periods in the intraseasonal cycle between chlorophyllaand sea surface temperature, wind stress curl or wind speed using cross wavelet transform. [ABSTRACT FROM AUTHOR]

The wave spectrometer operated by the China–France Oceanography Satellite (CFOSAT) can provide global ocean wave observation data. Although a lot of work on calibration and verification has been carried out in the open oceans dominated by swells, the quality of the data in the relatively enclosed sea area with complex terrain still lacks sufficient examination. The objective of this study is to assess the performance of the significant wave height data of the CFOSAT in the South China Sea (SCS), a unique sea area characterized by semi-enclosed basin and multi-reef terrain, and to recognize the environmental factors affecting the data quality. Compared against the long-term observations from five mooring or buoy sites, we find that the data is well performed in the relatively open and deep areas of the SCS, with an average correlation coefficient as high as 0.87, and a low average root-mean-square error of 0.47 m. However, the combined effects of complex topography, monsoons, and swell proportion variation will affect the performance of data. In the southern deep areas, the waves may be affected by a large number of dotted reefs, leading to wave deformations and energy dissipation in different seasons. In the northern nearshore areas, waves tend to be sheltered by the land or distorted by the shallow topography effects. These processes make it difficult for the swell to fully develop as in the open oceans. The low proportion of swell is a disadvantage for the CFOSAT to correctly observe the wave data and may lead to possible errors. Our results emphasize the importance of more verification when applying the CFOSAT data in certain local seas, and the necessity to adjust the algorithm of inverting wave spectra according to specific environmental factors. [ABSTRACT FROM AUTHOR]

The large and variable riverine inflow to Arctic continental shelves strongly influences their chemical, biological, and optical properties. The Beaufort Sea receives the largest amount of suspended sediments amongst all Arctic shelves, with sediment-laden Mackenzie river waters strongly influencing bio-optical properties on the shelf. Here, we developed two regional algorithms for the estimation of total suspended matter (TSM) concentration using Medium Resolution Imaging Spectrometer (MERIS) spectral bands, based onin situoptical and suspended particulate data collected in the summer during the Canadian Arctic Shelf Exchange Study (CASES) in 2004 and during the Arctic Coastal Ecosystem Study (ACES) in 2010. The band ratio (whereRrsis remote-sensing reflectance)Rrs,560/Rrs,490was best correlated with low TSM concentrations (less than 3.0 g m−3), while higher TSM concentrations were well correlated toRrs,681/Rrs,560. An empirical piecewise algorithm is thus proposed with the switch between the ratios being triggered byRrs,681/Rrs,560at a threshold value of 0.6. The second algorithm made use of support vector machines (SVMs) as a nonlinear transfer function between TSM concentrations and remote-sensing reflectance ratiosRrs,681/Rrs,560,Rrs,665/Rrs,560, andRrs,560/Rrs,490. Results show that both algorithms perform better (31% and 25%, respectively) than other published TSM algorithms including the MERIS Case 2 water processor (C2R) neural network algorithm in the study area. [ABSTRACT FROM AUTHOR]

Marine heavy metals in the particulate phase are considered to be undetectable from remote sensing since their minor spectral signal is masked by marine optical constitutes. However, over 80% of heavy metals adsorb to and complex with the suspended sediment and the quantity of adsorbed heavy metals strongly depends on suspended sediment load and size. Thus, the suspended sediment load and size could be useful information to estimate heavy metal levels through remote-sensing techniques. We investigate the potential to derive heavy metal concentration, using zinc as an example. Eight cruises in the Pearl River Estuary were carried out to measure zinc concentrations in the particulate phase (Czn) and remote-sensing reflectance (Rrs) data from 2009 to 2010. The relationship ofRrsratio in the near infrared bands and the scattering spectral slope (which indicates particle size distribution (PSD)) is first proposed. According to a previously established suspended sediment algorithm for the study area and the newly proposed relationship of remote-sensing reflectance and suspended sediment size, a piecewise algorithm is developed to retrieveCzn. The accuracies of the algorithm developed here (correlation coefficient (r) = 0.88, mean relative error (MRE) = 24.7% and root mean square error (RMSE) = 5.51) are higher than those algorithms only considering suspended sediment load (r = 0.79, MRE = 35.3% and RMSE = 8.93) or size (r = 0.78, MRE = 30.0% and RMSE = 7.19). The algorithm is applied to Medium Resolution Imaging Spectrometer (MERIS) full resolution data to obtainCzndistribution in the Pearl River Estuary. TheCznfrom image is mainly in the range from 10 to 63 μg l−1, which is consistent with thein situdata ranges (5.67–86.62 μg l−1). [ABSTRACT FROM AUTHOR]

Abstract: Approximately thirteen years of mean sea level anomaly (MSLA) and chlorophyll (Chl) data in the northern South China Sea (NSCS) were analysed to investigate the influence of a nonlinear, mesoscale eddy on ecological and biogeochemical processes. Over two thousand mesoscale eddies were identified and tracked using a new sea surface height-based method and approximately 40% of these eddies were nonlinear. A westward co-propagation of Chl and MSLA signals at a speed of approximately 0.07ms−1 was found to correspond well with the variability of Chl within cyclonic and anticyclonic eddies. The covariability relationships were different depending on the season. The results of a lagged cross correlation between MSLA and Chl, as well as Chl composite averaging within mesoscale eddies, showed that eddy advection dominates the Chl dipole structure within mesoscale eddies. This mechanism was further confirmed by the significant correlations of the west-to-east Chl difference with background Chl gradient (R=0.32 for cyclonic eddies and R=−0.20 for anticyclonic eddies) and eddy scale (R=0.33 for cyclonic eddies and R=−0.21 for anticyclonic eddies). Moreover, the strong correlation (0.44) between the in-to-out Chl difference and amplitude for the cyclonic eddy implied that eddy pumping contributes to the high Chl levels near the centre of cyclonic eddy. [Copyright &y& Elsevier]

In the original article Fig. 3 [ABSTRACT FROM AUTHOR]

The abundance of phytoplankton is generally estimated by measuring the chlorophyll-a concentration (Cchla), which is an important factor in photosynthesis and can be used to analyze the density and biomass of phytoplankton in the ecosystem. The band-ratio-based empirical or semi-analytical algorithms are operationally applied to retrieve Cchla in global oceans, which generally experience difficulties from the diversity of optical properties and the complexity of the radiative transfer equations in analytical analyses, respectively. With an attempt to develop an accurate Cchla retrieval model for the optically complex coastal and estuarine waters, this study aimed to explore the deep learning (DL) methods in satellite retrieval of Cchla. A two-stage convolutional neural network (CNN), named Cchla-Net, was proposed, which utilized the spectral information of remote sensing reflectances at MODIS/Aqua's visible bands. In the first-stage phase, the Cchla-Net was pretrained by a set of remote sensing patches, in which the Cchla was generated from an existing model (OC3M). The pretrained results were than used as the initial values to refine the network with the synthetic oversampled in-situ dataset in the second-stage training phase. Using in-situ samples for training with the new initial values has a higher probability to reach the global optimum. The quantitative analyses showed that the two-stage training was more likely to achieve a global optimum in the optimization than the one-stage training. Matchups of the in-situ Cchla measurements were used to evaluate the retrieval models. Results showed that the proposed Cchla-Net produced obvious better performance than the empirical and semi-analytical algorithms, implying the DL method was more effective for optically complex waters with extremely high Cchla. This study provided an applicable method for remote sensing retrieval of Cchla, which should be helpful for studying the spatial distribution and temporal variability in the productive Pearl River estuary (PRE) waters. [ABSTRACT FROM AUTHOR]

The oceanic Kármán vortex street is an important hydrokinetic phenomenon caused by the unsteady separation of sea currents in the wake of an obstacle. This study quantitatively analyzed the characteristics of the small-scale vortex street of Didicas Island in the Luzon Strait based on multimission satellite data. Five groups of vortex streets were captured, and each group was observed by two satellite images within one hour. Based on the displacement and change in the vortex street within one hour, we found that the formation time of a single vortex is longer than 40 min. The vortex propagation speed behind the island is approximately 0.98 m s−1 (ranging from 0.66–1.22 m s−1). The incoming velocity was calculated using the vortex propagation speed and the aspect ratio based on a vortex propagation model, which ranges from 0.72 to 1.47 m s−1 The incoming speed is 1.6–2.3 times the geostrophic speed extracted from AVISO data, implying that the contribution of non-geostrophic flow to the total flow field is comparable to that of geostrophic flow in this region. [ABSTRACT FROM AUTHOR]

Transcription factors, as the convergence points of multiple signaling pathways in eukaryotic cells, are closely involved in disease development. Pax‐8, an important transcription factor belonging to the Pax family, exerts a crucial influence on the regulation of gene expression required for both physiological conditions and pathological processes. Pax‐8 contributes to the pathogenesis of many human diseases, ranging from cardiovascular disease to many cancers, and therefore, it can be imagined that Pax‐8 holds great therapeutic potential. In this review, we summarize the structure, distribution, function, and regulatory mechanisms of Pax‐8 to provide a new research direction for Pax‐8. [ABSTRACT FROM AUTHOR]

Purpose: The research objective of this study is to use finite element analysis to investigate the impact of anterior cruciate ligament (ACL) injury on medial unicompartmental knee arthroplasty (UKA) and explore whether patients with ACL injuries can undergo UKA. Methods: Based on the morphology of the ACL, models of ACL with diameters ranging from 1 to 10mm are created. Finite element models of UKA include ACL absence and ACLs with different diameters. After creating a complete finite element model and validating it, four different types of loads are applied to the knee joint. Statistical analysis is conducted to assess the stress variations in the knee joint structure. Results: A total of 11 finite element models of UKA were established. Regarding the stress on the ACL, as the diameter of the ACL increased, when a vertical load of 750N was applied to the femur, combined with an anterior tibial load of 105N, the stress on the ACL increased from 2.61 MPa to 4.62 MPa, representing a 77.05% increase. Regarding the equivalent stress on the polyethylene gasket, a notable high stress change was observed. The stress on the gasket remained between 12.68 MPa and 14.33 MPa in all models. the stress on the gasket demonstrated a decreasing trend. The equivalent stress in the lateral meniscus and lateral femoral cartilage decreases, reducing from the maximum stress of 4.71 MPa to 2.61 MPa, with a mean value of 3.73 MPa. This represents a reduction of 44.72%, and the statistical significance is (P < 0.05). However, under the other three loads, there was no significant statistical significance (P > 0.05). Conclusion: This study suggests that the integrity of the ACL plays a protective role in performing medial UKA. However, this protective effect is limited when performing medial UKA. When the knee joint only has varying degrees of ACL injury, even ACL rupture, and the remaining structures of the knee joint are intact with anterior-posterior stability in the knee joint, it should not be considered a contraindication for medial UKA. [ABSTRACT FROM AUTHOR]

Background: Coronary heart disease (CHD) has become a worldwide public health problem. Genetic factors are considered important risk factors for CHD. The aim of this study was to explore the correlation between CYP4A22 gene polymorphism and CHD susceptibility in the Chinese Han population. Methods: We used SNPStats online software to complete the association analysis among 962 volunteers. False-positive report probability analysis was used to confirm whether a positive result is noteworthy. Haploview software and SNPStats were used for haplotype analysis and linkage disequilibrium. Multi-factor dimensionality reduction was applied to evaluate the interaction between candidate SNPs. Results: In overall and some stratified analyses (male, age ≤ 60 years or CHD patients complicated with hypertension), CYP4A22-rs12564525 (overall, OR = 0.83, p-value is 0.042) and CYP4A22-rs2056900 (overall, OR = 1.22, p-value is 0.032) were associated with the risk of CHD. CYP4A22-4926581 was associated with increased CHD risk only in some stratified analyses. FPRP indicated that all positive results in our study are noteworthy findings. In addition, MDR showed that the single-locus model composed of rs2056900 is the best model for predicting susceptibility to CHD. Conclusion: There are significant associations between susceptibility to CHD and CYP4A22 rs12564525, and rs2056900. [ABSTRACT FROM AUTHOR]

Purpose: The research aimed to detect the association between single nucleotide polymorphisms (SNPs) in CYP4V2 gene and coronary heart disease (CHD) risk. Methods: This case–control study included 487 CHD subjects and 487 healthy individuals. Logistic regression was performed to analyze the connection between five SNPs in CYP4V2 (rs1398007, rs13146272, rs3736455, rs1053094, and rs56413992) and CHD risk, and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to evaluate the connection. Results: As a result, we found that rs56413992 T allele (OR = 1.36, 95% CI = 1.09–1.70, p = 0.007) and CT genotype (OR = 1.40, 95% CI = 1.06–1.83, p = 0.017) were significantly associated with an increased risk of CHD in the overall analysis. Precisely, rs56413992 was linked to an elevated risk of CHD in people aged > 60, males, smokers and drinkers. The study also indicated that rs1398007 was linked to an increased CHD risk in drinkers. In addition, rs1053094 was correlated with a decreased risk of CHD complicated with diabetes mellitus (DM), and rs1398007 was correlated with a decreased risk of CHD complicated with hypertension (HTN). Conclusion: This study was the first to experimentally demonstrate that CYP4V2 rs56413992 was associated with the risk of CHD, which will provide a certain reference for revealing the pathogenesis of CHD. [ABSTRACT FROM AUTHOR]

The hydrocarbon-bearing Baiyinchagan sag is located in the west of the Erlian Basin in the Inner Mongolia, Northern China. Its potential source rocks include the Lower Cretaceous Aershan, Tenggeer and Duhongmu 1 Formations. The former two formations are major source rocks. They are dominated by dark mudstone with the largest thickness of 560-600 m, and mainly distributed in the western sub-sag. In this study, temperature data from three wells used to calculate the present-day geothermal gradient in the sag, and used 144 vitrinite reflectance measurements from 35 wells together with seven apatite fission track data from seven wells to reconstruct the Mesozoic and Cenozoic thermal history. The results show that the present-day geothermal gradient is 35.1 °C/km. In the Early Cretaceous, the geothermal gradient was 40.0–42.1 °C/km during the early deposition of the Aershan Formation (135–110 Ma), and then increased to 49.9–56.4 °C/km at the end deposition of the Saihantala Formation (100–95 Ma). The geothermal gradient decreased to a present-day value of 32.0–35.4 °C/km. Using this model of thermal history, combined with the source rock geochemistry, the maturation histories of three source rock intervals, including the Aershan, Tenggeer and Duhongmu 1 Formations, were modeled. The modeled results suggest that source rock maturation was controlled by palaeo geothermal gradient, and that source rocks in the eastern sub-sag have not reached hydrocarbon generation threshold (0.5% R o ). In the western sub-sag, Aershan Formation source rocks reached a high mature (1.0%

A MODIS-based algorithm was developed to investigate the impact of Typhoon Vicente on the total suspended solid concentration in the Pearl River Estuary. This algorithm used two high resolution bands at 645 nm and 555 nm to map the concentrations. Regression between the remote sensing reflectance and in situ total suspended solid concentration showed good correlation (R2= 0.91), indicating that the algorithm was valid for the high turbid waters in the Pearl River Estuary. MODIS-derived maps showed different total suspended solid concentration anomalies in different sub-regions of the estuary during the passage of Typhoon Vicente. In western inlets, the increase of total suspended solids (maximum values of 22.20 g m−3before and 55.71 g m−3after the typhoon) was possibly related to the larger rainfall discharge from the Pearl River. In Lingdingyang, the increase of total suspended solids (maximum values of 19.60 g m−3before and 44.59 g m−3after the typhoon) might be the result of typhoon-induced resuspension. In the southeastern portion of the Estuary, due to the typhoon-induced current, a significant decrease of total suspended solid area (decreased by 10 g m−3) was observed. Different changes were observed in different sub-regions under the influence of the typhoon, implying the complicated hydrological environment is an important feature in the Pearl River Estuary. [ABSTRACT FROM AUTHOR]

Coronary artery disease (CAD) is a common comorbidity of gastroesophageal reflux disease. Since the distal esophagus and heart share a common afferent vagal supply, the delivery of radiofrequency in the distal esophagus can stimulate the coronary artery and induce acute myocardial infarction in a patient with CAD. Acute myocardial infarction may occur after esophageal radiofrequency (RF) therapy on patients with gastroesophageal reflux disease (GERD). Coronary artery disease and related risk factors should be reasonably excluded before treating GERD with esophageal RF therapy (Stretta procedure). [ABSTRACT FROM AUTHOR]

The health and safety of marine ecosystems are directly related to the health and well-being of all mankind. Factors such as insufficient effective monitoring data and lack of scientific decision-making information have affected the smooth implementation of the marine sustainable development goals (SDG 14) to a certain extent. Big Earth Data possesses macroscopic, dynamic and objective monitoring capabilities, and can play an important role in supporting the realization of the sustainable development goals of the ocean. With the support of the Strategic Priority Research Program of Chinese Academy of Sciences, and based on technologies and methods related to Big Earth Data, China has effectively carried out specific practices such as the production of missing ocean data sets and the construction of target localization models. Based on the above analysis, the study puts forward suggestions such as actively participating in the sharing of Big Earth Data in the international community, strengthening the drive of scientific and technological innovation in the realization of sustainable marine development goals, and deep participation in the United Nations Ocean Governance Plan. [ABSTRACT FROM AUTHOR]

A support vector machine (SVM) regression algorithm was developed for estimating the chlorophyll-a concentration (C chla) in the turbid estuarine waters of the Pearl River estuary (PRE) based on visible infrared imaging radiometer suite (VIIRS) ocean color data. The proposed SVM algorithm outperformed the OC3 algorithm in the turbid waters. The temporal variation and spatial distribution of SVM-based monthly C chla products were determined during 2012 and 2018. By analyzing the monthly average C chla products and ancillary data, the underlying mechanisms of the C chla coastal summer plume jet and winter bloom were revealed. The C chla coastal plume jet was often observed in June, when the zonal wind direction changed from westward to eastward and the river runoff reached its maximum value of the year. The winter bloom in the ocean area was attributed to strong mixing in the upper layer, which resulted from cooling-induced buoyancy changes. • A SVM model was developed for the estimation of chlorophyll-a concentration. • Spatial distribution and temporal variation of chlorophyll-a concentration was reveal. • The underlying mechanisms of the summer plume jet and winter bloom were discussed. [ABSTRACT FROM AUTHOR]

New evidences provided that the tropical cyclone (TC) Linfa in 2015 induced looping path of Kuroshio invasion into the northeastern South China Sea (NESCS) through the northwestern Luzon Strait (LS), based on the in-situ measurements, satellite data and model output data. This TC-enhanced Kuroshio invasion with low nutrients and denser waters suppressed the TC "Wind Pump" induced upwelling and nutrients uptake, and therefore inhibited the Chlorophyll a concentration (Chl-a) increase from surface to ~50 m in the open ocean of the NESCS. The TC-induced Kuroshio invasion promoted the generation of the strong cyclonic eddy to its left side where weak Ekman Pumping Velocity was observed. This enhancing cyclonic eddy then dominated the nutrients uplift and increased the surface and subsurface (0–50 m) Chl-a through eddy pumping rather than Ekman Pumping. The TC-declined anti-cyclonic eddy, which shoaled the Mixed Layer Depth (MLD), benefited to the nutrient uptake through TC-induced upwelling and thereby increased the surface Chl-a and raised the Chl-a Maximum Layer (CML) to ~20 m over the southwestern LS. The temporal Chl-a variations were also influenced by TC intensities and biochemical processes. The air-sea heat budget analysis indicated that, the air-sea heat exchange contributed to nearly 80% of the sea surface cooling (SST cooling) over the northwestern LS with Kuroshio invasion, while eddy-induced upwelling dominated the SST cooling over the western LS, and the wind-driven upwelling (and mixing) controlled the SST cooling over the southwestern LS. These different formations of SST cooling then played important role in Chl-a variations. This study is the first case of TC "Wind Pump" induced Chl-a variations considering air-sea heat exchange, Kuroshio invasion and mesoscale eddies over LS, which would help to evaluate the influence of TCs over the other major heat transport arteries of the world ocean: The Gulf Stream area. Unlabelled Image • TC "Wind Pump" enhanced Kuroshio invasion which then inhibited the surface Chl-a. • Eddy-induced upwelling dominated Chl-a increase rather than wind-driven upwelling. • TC-enhanced Kuroshio invasion reduced a cyclonic eddy which right on its way. • TC-enhanced Kuroshio conduced to a cyclonic eddy generation in its left side. • Air-sea heat exchange dominated SST cooling which then inhibited Chl-a increase. [ABSTRACT FROM AUTHOR]

We evaluated six empirical and semianalytical models of the diffuse attenuation coefficient at 490 nm (Kd(490)) using an in situ dataset collected in the Pearl River estuary (PRE). A combined model with the most accurate performance (correlation coefficient, R2 = 0.92) was selected and applied for long-term estimation from 2003 to 2017. Physical and biological processes in the PRE over the 14-year period were investigated by applying satellite observations (MODIS/Aqua data) and season-reliant empirical orthogonal function analysis (S-EOF). In winter, the average Kd(490) was significantly higher than in the other three seasons. A slight increasing trend was observed in spring and summer, whereas a decreasing trend was observed in winter. In summer, a tongue with a relatively high Kd(490) was found in southeastern Lingdingyang Bay. In Eastern Guangdong province (GDP), the relatively higher Kd(490) value was found in autumn and winter. Based on the second mode of S-EOF, we found that the higher values in the eastern GDP extended westward and formed a distinguishable tongue in winter. The grey relational analysis revealed that chlorophyll-a concentration (Cchla) and total suspended sediment concentration (Ctsm) were two dominant contributors determining the magnitude of Kd(490) values. The Ctsm-dominated waters were generally located in coastal and estuarine turbid waters; the Cchla-dominated waters were observed in open clear ocean. The distribution of constituents-dominated area was different in the four seasons, which was affected by physical forces, including wind field, river runoff, and sea surface temperature. [ABSTRACT FROM AUTHOR]

The Bermuda Testbed Mooring (BTM) and Bay of Bengal Ocean Acidification (BOBOA) mooring measurements were used to identify changes in the partial pressure of CO2 at the sea surface (pCO2sea) and air-sea CO2 fluxes (FCO2) associated with passage of two tropical cyclones (TCs), Florence and Hudhud. TC Florence passed about 165 km off the BTM mooring site with strong wind speeds of 24.8 m s–1 and translation speed of 7.23 m s–1. TC Hudhud passed about 178 km off the BOBOA mooring site with wind speeds of 14.0 m s–1 and translation speed of 2.58 m s–1. The present study examined the effect of temperature, salinity, dissolved inorganic carbon (DIC), total alkalinity (TA), air-sea CO2 flux, and phytoplankton chlorophyll a change on pCO2sea as a response to TCs. Enhanced mixed layer depths were observed due to TCs-induced vertical mixing at both mooring sites. Decreased pCO2sea (–15.16±5.60 μatm) at the BTM mooring site and enhanced pCO2sea (14.81±7.03 μatm) at the BOBOA mooring site were observed after the passage of Florence and Hudhud, respectively. Both DIC and TA are strongly correlated with salinity in the upper layer of the isothermal layer depth (ILD). Strong (weak) vertical gradient in salinity is accompanied by strong (weak) vertical gradients in DIC and TA. Strong vertical salinity gradient in the upper layer of the ILD (0.031 psu m–1), that supply much salinity, dissolved inorganic carbon and total alkalinity from the thermocline was the cause of the increased pCO2sea in the BOBOA mooring water. Weak vertical salinity gradient in the upper layer of the ILD (0.003 psu m–1) was responsible for decreasing pCO2sea in the BTM mooring water. The results of this study showed that the vertical salinity gradient in the upper layer of the ILD is a good indicator of the pCO2sea variation after the passages of TCs. [ABSTRACT FROM AUTHOR]

Abstract Spatio-temporal variability of the suspended sediment concentration (SSC) in the Pearl River Estuary (PRE) is analyzed over 13 years (2003–2015) using MODIS-Aqua Level-1B data. A unique seasonal SSC variability was found. During the wet season, the SSC in the northwestern estuary (NWE) is high, which could reach up to 100 mg/L, while during the dry season it suffers from a markedly decrease. Over the southeastern estuary (SEE), however, the pattern is reversed. This seasonality is mainly affected by freshwater discharge, winds and water column stratification. During the wet season, freshwater discharge dominates the SSC in the NWE while stratification and water discharge control the SSC variation in the SEE. During the dry season, freshwater discharge also plays a more important role in changing the SSC in the NWE, while the combined effect of wind mixing and tidal mixing dominates the SSC in the SEE. The interannual variability of the SSC is revealed by an EOF analysis. The first mode is highly related to water discharge of the Pearl River, indicating that the interannual variability is mainly subject to the rainfall over the Pearl River basin. The long-term SSC trend is characterized by a general decrease across the entire estuary and proved to be closely related to human activity. The reduction rate of the SSC varies spatially and seasonally. Spatially, the northern West Shoal and upper eastern part of the PRE suffer from a much greater SSC decrease, while the rest of the estuary, especially the southern West Shoal, is relatively less influenced. Seasonally, the decreasing rate in the dry season (49.3%) is higher than that in the wet season (30.1%). Highlights • Seasonal variability of the SSC in the NWE and SEE are controlled by different factors. • Interannual variability of the SSC is subject to the freshwater discharge. • A significant decreasing trend of the SSC is detected, presumably due to dam constructions. • The reduction rate of the SSC in the dry season is higher than that in the wet season. [ABSTRACT FROM AUTHOR]

The influence of oceanic mesoscale eddies on their internal phytoplankton levels varies at different developmental stages. Based on 12 years of satellite ocean color observations, we investigated the variability of phytoplankton inside 4564 anticyclonic eddies and 3675 cyclonic eddies off eastern Australia in different development stages using the method of composited average analysis. The results indicated that the lowest level of chlorophyll was observed in the forth (decay) development stage for anticyclonic eddies, which was associated with the warmest SST, largest eddies amplitude, rotation speeds, angular velocities and surface water convergence. It is indicated that downwelling induced by anticyclonic eddies dominates the chlorophyll variations. Because the convergence induced by the ageostrophic velocity components occurred throughout the eddy's development stage, relaxation of the density perturbations (upwelling) associated with eddy decay was not observed in this study. Chlorophyll concentration near the center of cyclonic eddies decreased from the first to the middle stage, and then increased to the largest levels at the last stage. Although vertical motions induced by the ageostrophic velocity components varied from divergence to convergence during the development of an eddy, a higher eddy-ambient water exchange occurred and dominated the increases in total divergence and chlorophyll concentration in the last stage. [ABSTRACT FROM AUTHOR]

To obtain cheap, low-toxic, efficient and robust visible-light photocatalyst, a controlled calcination strategy is proposed for converting unstable ZnX (X=Se, Te) nanospheres (NSs) to ZnX-ZnO hybrid nanospheres (HNSs) with an appropriate composition and structure. Under such a conception, ZnSe-ZnO HNSs with various compositions were prepared by calcining ZnSe NSs under different conditions. Their morphology, composition, crystal structure, and optical absorption property were found to be highly dependent on their calcination condition. When serving as the catalyst for photodegrading organic dyes, they exhibited an attractive composition/structure-dependent photocatalytic activity and enhanced photostability. Particularly, the HNSs prepared by calcining at 500 °C for 4.0 h demonstrated the highest photocatalytic activity and excellent photostability, only taking 4.5 and 5.5 h to degrade 97.3 % methylene blue (MB) and 93 % ethyl violet (EV), respectively, under visible irradiation. The reason why such HNSs possessed the best photocatalytic performance was then intensively explored from different points of view. Moreover, we also extended this calcination protocol to prepare ZnTe-ZnO HNSs, whose photocatalytic performance was proven to be much better than that of pure ZnTe NSs as expected. We believe the strategy for fabricating such hybrid nanospheres and the exploration on their excellent photocatalytic performance will definitely benefit the preparation of high-efficient visible-light catalyst as well as the better understanding of its composition/structure-dependent photocatalytic activity. [ABSTRACT FROM AUTHOR]

The flux and seasonality of planktonic foraminifera were studied through a time-series sediment trap deployed in the Xisha Trough, South China Sea from June 2009 to August 2011. The general flux pattern for planktonic foraminifera showed high values during the winter half-year/season (from late September/October to February) and low flux during the rest of the year. This flux pattern contrasts with the bimodal pattern in the central and southern South China Sea, which shows two high flux peaks corresponding to the prevailing summer and winter monsoon periods, respectively. Apparent interannual flux differences, which may be related to the climate change from an El Niño year to a La Niña year, were observed. Monsoonal driven seasonality is most prominent inPulleniatina obliquiloculata, Neogloboquadrina dutertreiandGlobigerina bulloides, with over 80% of their species-specific fluxes (93% forG. bulloides) occurring from late September/October to February.Globigerinoides sacculiferandGlobigerinoides rubershow similar seasonality, generally following the trend of the total flux of planktonic foraminifer.G. bulloidesmay have the potential to be developed as a winter proxy-species.Globigerinoides conglobatusmostly appears in June to August and can be developed as a summer proxy-species. [ABSTRACT FROM PUBLISHER]

The wave data measured by CFOSAT (China France Oceanography Satellite) have been validated mainly based on numerical model outputs and altimetry products on a global scale. It is still necessary to further calibrate the data for specific regions, e.g., the southern South China Sea. This study analyses the practicability of calibrating the dominant wavelength by using artificial neural networks and mean impact value analysis based on two sets of buoy data with a 2-year observation period and contemporaneous ERA5 reanalysis data. The artificial neural network modeling experiments are repeated 1000 times randomly by Monte Carlo methods to avoid sampling uncertainty. Both experimental results based on the random sampling method and chronological sampling method are performed. Independent buoy observations are used to validate the calibration model. The results show that although there are obvious differences between the CFOSAT wavelength data and the field observations, the parameters observed by the satellite itself can effectively calibrate the data. In addition to the wavelength, nadir significant wave height, nadir wind speed, and the distance between the calibration point and satellite observation point are the most important parameters for the calibration. Accurate data from other sources, such as ERA5, would be helpful to further improve the calibration results. The variable contributing the most to the calibration effect is the mean wave period, which virtually provides relatively accurate wavelength information for the calibration network. These results verify the possibility of synchronous self-calibration for the CFOSAT wavelength data and provide a reference for the further calibration of the satellite products in other regions. [ABSTRACT FROM AUTHOR]

The China-France Oceanography SATellite (CFOSAT), launched on 29 October 2018, is a joint mission developed by China and France. To evaluate the CFOSAT wind product, L2B swath data with a spatial resolution of 25 × 25 km were compared with in situ measurements between December 2018 and December 2020. The in situ measurements were collected from 217 buoys. All buoy winds were adjusted to 10 m height using a simple logarithmic correction method. The temporal and spatial separations between the CFOSAT and in situ measurements were restricted to less than 30 min and 0.25°. The results indicate that the CFOSAT wind retrievals agree well with the buoy measurements. The root mean square errors (RMSEs) of wind vectors were 1.39 m s−1 and 34.32° and negligible biases were found. In the near shore under rain-free conditions, the RMSEs were enhanced to 1.42 m s−1 and 33.43°. Similarly, the RMSEs were reduced to 1.16 m s−1 and 30.41° offshore after the rain effect was removed. After winds less than 4 m s−1 were removed, the RMSE of wind directions was reduced to 19.69°. The effects of significant wave height, air-sea temperature difference, sea surface temperature, atmospheric pressure and ocean surface current on the wind residuals were assessed. The performance of wind retrievals under the passage of tropical cyclones was evaluated. The evaluation results show that the CFOSAT wind retrievals satisfy the accuracy requirements of scientific research, although some improvements are needed to enhance the performance. [ABSTRACT FROM AUTHOR]

• A satellite concept Ocean Surface Current multiscale Observation Mission is proposed. • OSCOM will directly measure surface currents with a resolution of ~10 km. • OSCOM will observe ocean surface current, vector wind, and temperature simultaneously. • OSCOM will help the study on non-equilibrium ocean state and air-sea interaction. • OSCOM will provide an improved pathway to data assimilation for ocean prediction. Ocean current is one of the major drivers of water mass, energy, and biogeochemical cycles in the global ocean–atmosphere boundary layer and also a key variable in the formation of extreme climate events (e.g., El Niño). Direct measurement of the global ocean surface current is of great scientific interest and application value for understanding multiscale ocean dynamics, air-sea interaction, ocean mass and energy balance, and ocean carbon budget, as well as their variabilities under climate change. This paper reviews the state-of-the-art developments of ocean dynamics and technology on the observation of multiscale ocean circulation and related scientific frontiers. Presently, measurements of global ocean surface currents, which are mainly geostrophically derived from satellite altimeter data, are only available to resolve quasi-geostrophic current at large- to meso-scale in the off-equatorial open ocean. This becomes a bottleneck impeding the application and the development of ocean circulation dynamics. With the ambition of breaking the bottleneck, Ocean Surface Current multiscale Observation Mission (OSCOM) will launch a satellite equipped with a Doppler Scatterometer to directly measure ocean surface currents for the first time with a very high horizontal resolution of 5–10 km and a 3-day global coverage. Through carrying a Surface Temperature Infrared Radiometer and a Surface Temperature Microwave Radiometer, the OSCOM satellite is supposed to have the capability of observing ocean surface current, ocean surface vector wind, and sea surface temperature simultaneously. With a cutting-edge design, OSCOM will provide an in-depth picture of non-equilibrium ocean state and air-sea interaction from mesoscale to submesoscale, and helps to construct the fine structure of deep ocean current through a combination with Array for Real-time Geostrophic Oceanography profiling. Those direct measurements and derived dynamic parameters will further facilitate analyses of ocean carbon budget and ocean biogeochemical cycle, and provide a novel and improved pathway to data assimilation, coupling of General Circulation Models, and the Earth System Modelling for ocean prediction and climate change. [ABSTRACT FROM AUTHOR]

Hangzhou Bay (HZB) is the largest macro-tidal bay in China, where suspended sediment concentrations are significantly modulated by tidal oscillations. This makes it an ideal area for the study of the impact of tide on temporal–spatial variation in suspended sediment. The GaoFen-4 (GF-4) satellite is the first high-resolution geosynchronous orbiting satellite of China. It exhibits the unique advantages of capturing minute variations and finer details of total suspended matter (TSM) due to the enhancement in spatial resolution (50 m) and observation time interval (20 s). In this study, TSM concentration of the HZB was retrieved based on the GF-4 satellite. The spatial distribution and minute variations of TSM concentration under the ebb tide from 7:30 to 7:40 a.m. on 28 August 2017, were analyzed. The results showed that the average TSM concentration inside HZB was (371.8 ± 1.8) mg/L. There was a linearly increasing trend of TSM concentration at ebb tide, with an increment of (3.96 ± 0.31) (mg/L)/min, and a more significant increase was observed in the high TSM areas. This increase in TSM concentration was associated with both the bottom topography and tide processes. The tidal potential energy generated by the tidal range and the strong shear stress generated by the high current velocity both led to the re-suspension of the sedimentary particles, which affected the variation of TSM concentration. In addition, the influence of bottom topography changed the intensity of re-suspension and also affected the distribution of TSM concentration in HZB. [ABSTRACT FROM AUTHOR]

Water transparency, measured with Secchi disk depth (SDD), is an important parameter for describing the optical properties of a water body. This study evaluates variations of SDD and related impact factors in the Bohai and Yellow Seas (BYS). Based on a new mechanistic model proposed by Lee et al. (2015) applied to MODIS remote sensing reflectance data, climatological SDD variation from 2003 to 2019 was estimated. The annual mean images showed an increasing trend from the coastal zone to the deep ocean. Lower values were found in the Bohai Sea (BHS), while higher values observed in the center of the southern Yellow Sea (SYS). Additionally, the entire sea has shown a decreasing temporal tend, with the variation rate lowest in the BHS at 0.003 m y−1, and highest in the SYS at 0.015 m y−1. However, the weak increasing trend that appeared since 2017 suggests that water quality seems to have improved. Further, it displayed seasonal patterns of low in winter and spring and high in summer and autumn. The empirical orthogonal function (EOF) analysis of SDD variations over the BYS, shows that the first SDD EOF mode is the highest, strongly correlated with total suspended matter. With the high correlation coefficients of chromophoric dissolved organic matter, it illustrates that the SDD variation is mainly dominated by the optical components in the seawater, although correlation with chlorophyll-a is the weakest. The second and third EOF modes show that photosynthetically available radiation, sea surface temperature, sea surface salinity, and wind speed are the main covariates that cause SDD changes. Water transparency evaluation on a long-term scale is essential for water quality monitoring and marine ecosystem protection. [ABSTRACT FROM AUTHOR]

More than 1100 lakes covering an area greater than 4500 km2 are located on the Tibetan Plateau, and these lakes are important regulators of several large and famous rivers in Asia. The determination of hydrological changes that have occurred in these lakes can reflect climate change and supply scientific data to plateau environmental research. Data from high frequency (moderate-resolution imaging spectro-radiometer) MODIS images, altimetry, and the Hydroweb database collected during 2000–2015 were integrated in this study to delineate the detailed hydrological changes of 15 lakes in three basins—Inner Basin, Indus Basin, and Brahmaputra Basin—on the southern Tibetan Plateau. Seven of the 10 lakes in the Inner Basin presented increasing trends with various intensities, and the increasing rates in the area of four lakes (Nam Co, Selin Co, Zhari-namco, and Ngangze) were 1.62, 28.81, 2.27, and 3.70 km2/yr, respectively. The yearly increases in volume of the four lakes were 3.6, 9.44, 6, and 2.36 km3, respectively. A water balance equation was established for the four lakes based on lake volume changes to illustrate the contributions of precipitation, ground runoff, evaporation, and other factors. The results revealed that surface runoff was the major contributor to expansion, and lake surface evaporation was almost 2.76–3.86 times that of lake surface precipitation. The two lakes in Indus Basin, Rakshastal and Mapam Yumco, presented a slight retreat. As a representative of Brahmaputra Basin, Yamzho Yumco underwent a retreat of –3.49 km2/yr in area, –0.39 m/yr in level, and –0.19 km3/yr in volume. Decreasing precipitation, increasing evaporation, and the operation of a hydrological project were the main causes of its constant retreat. [ABSTRACT FROM AUTHOR]