Surface Elevation Research Articles

Magnetic nanoparticle loading and application of weak magnetic field to reconstruct the cake layer of coagulation-ultrafiltration process to achieve efficient antifouling: Performance and mechanism analysis

Abandoning the costly development of new membrane materials and instead directly remodeling the naturally occurring cake layer constitutes a dynamic, low-cost, long-lasting, and proactive strategy to "fight fouling with fouling". Several optimization strategies, including coagulation/modified magnetic seed loading and applying a weak magnetic force (0.01T) at the ultrafiltration end, improved the anti-fouling, retention, and sieving performances of conventional ultrafiltration process during the treatment of source water having complex natural organic matter (NOMs) and small molecule micropollutants. Two modified magnetic seeds we prepared were composite nano-seed particles (Fe3O4@SiO2-NH2 (FS) and Fe3O4@SiO2@PAMAM-NH2 (FSP)). Aim of the study was to regulate the formation of cake layer via comprehensive testing of the antifouling properties of optimized processes and related mechanistic studies. It was found to be essential to enhance the interception of xanthate and tryptophan proteins in the cake layer for improving the anti-fouling performance based on the correlation and redundancy analyses, while the use of modified magnetic seeds and magnetic field showed a significant positive impact on water production. Blockage modeling demonstrated the ability to form a mature cake layer during the initial filtration stage swiftly. This mitigated the risk of irreversible fouling caused by pore blockage during the early stage of coagulation-ultrafiltration. Morphologically, the reconstructed cake layer exhibited elevated surface porosity, an internal cavity channel structure, and enhanced roughness that can promote increased water flux and retention of water impurities. These optimized the maturity of the cake layer in both time and space. Density Functional Theory (DFT), Extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory, and Modified Extended Derjaguin-Landau-Verwey-Overbeek (MDLVO) calculations indicated aggregation behavior of matter on the cake layer to be enhanced effectively due to magnetic seed loading. This is mainly due to the strengthening of polar interactions, including hydrogen bonding, π-π* conjugation, etc., which can happen between the cake layer loaded with FSP and the organic matter. Under the influence of a magnetic field, magnetic force energy (VMF) significantly impacts the system by eliminating energy barriers. This research will provide innovative strategies for effectively purifying intricate source water through ultrafiltration while controlling membrane fouling.

Contrasting Changes of Debris-Free Glacier and Debris-Covered Glacier in Southeastern Tibetan Plateau

Debris-free and debris-covered glaciers are both extensively present in the southeastern Tibetan Plateau. High-precision and rigorous comparative observational studies on different types of glaciers help us to accurately understand the overall state of water resource variability and the underlying mechanisms. In this study, we used multi-temporal simultaneous UAV surveys to systematically explore the surface elevation change, surface velocity, and surface mass balance of two representative glaciers. Our findings indicate that the thinning rate in the debris-free Parlung No. 4 glacier UAV survey area was consistently higher than that in the debris-covered 24K glacier in 2020–2021 (−1.16 ± 0.03 cm/d vs. −0.36 ± 0.02 cm/d) and 2021–2022 (−0.69 ± 0.03 cm/d vs. −0.26 ± 0.03 cm/d). Moreover, the surface velocity of the Parlung No. 4 glacier was also consistently higher than that of the 24K glacier across the survey period, suggesting a more dynamic glacial state. The surface mass balance of the Parlung No. 4 glacier (2020–2021: −1.82 ± 0.09 cm/d; 2021–2022: −1.30 ± 0.09 cm/d) likewise outpaced that of the 24K glacier (2020–2021: −0.81 ± 0.07 cm/d; 2021–2022: −0.70 ± 0.07 cm/d) throughout the observation period, which indicates that the debris cover slowed the glacier’s melting. Additionally, we extracted the melt contribution of the ice cliff area in the 24K glacier and found that the melt ratio of this ‘hotspot’ area ranged from 10.4% to 11.6% from 2020 to 2022. This comparative analysis of two representative glaciers provides evidence to support the critical role of debris cover in controlling surface elevation changes, glacier dynamics, and surface mass balance.

The complex basal morphology and ice dynamics of the Nansen Ice Shelf, East Antarctica

Abstract. Ice shelf dynamics and morphology play an important role in the stability of floating bodies of ice by driving fracturing that can lead to calving, in turn impacting the ability of the ice shelf to buttress upstream grounded ice. Following a 2016 calving event at the Nansen Ice Shelf (NIS), East Antarctica, we collected airborne and ground-based radar data to map ice thickness across the shelf. We combine these data with published satellite-derived data to examine the spatial variations in ice shelf draft, the cause and effects of ice shelf strain rates, and the possibility that a suture zone may be channelizing ocean water and altering patterns of sub-ice-shelf melt and freeze-on. We also use our datasets to assess limitations that may arise from relying on hydrostatic-balance equations applied to ice surface elevation to determine ice draft morphology. We find that the Nansen Ice Shelf has a highly variable basal morphology driven primarily by the formation of basal fractures near the onset of the ice shelf suture zone. This morphology is reflected in the ice shelf strain rates but not in the calculated hydrostatic-balance thickness, which underestimates the scale of variability at the ice shelf base. Enhanced melt rates near the ice shelf terminus and in steep regions of the channelized suture zone, along with relatively thin ice in the suture zone, appear to represent vulnerable areas in the NIS. This morphology, combined with ice dynamics, induce strain that has led to the formation of transverse fractures within the suture zone, resulting in large-scale calving events. Similar transverse fractures at other Antarctic ice shelves may also be driven by highly variable morphology, and predicting their formation and evolution could aid projections of ice shelf stability.

The Influence of Vegetation on Climate Elements in Northwestern China

Vegetation plays a crucial role in maintaining the balance between nature, water and soil resources. However, understanding its impact mechanisms in arid and semi-arid areas remains limited. This study aims to analyze the spatial–temporal characteristics of the vegetation leaf area index (LAI) and climate elements in typical regions of northwest China and the correlations between LAI and climate elements; it also aims to explore the influence of regional vegetation growth on climate change. The results reveal significant correlations between LAI and various climate elements. Specifically, within the same region, surface temperature, precipitation, vegetation transpiration, and total evaporation show positive correlations with the LAI, whereas surface albedo shows a negative correlation. Vegetation may affect climate through both heat and water exchange between the land and atmosphere. Increased vegetation leads to the enhanced absorption of solar radiation by the land surface, elevating surface temperature. Increased levels of vegetation also increase vegetation transpiration and total evaporation, increasing the water vapor content in the atmosphere and thus leading to increased surface precipitation. Therefore, vegetation distribution plays a role in climate change, and ecological restoration projects in the northwest region hold significant potential for addressing ecological challenges in its arid and semi-arid areas.

PRMT5 Promotes T follicular helper Cell Differentiation and Germinal Center Responses during Influenza Virus Infection.

Protein arginine methyltransferases (PRMTs) modify diverse protein targets and regulate numerous cellular processes; yet, their contributions to individual effector T cell responses during infections are incompletely understood. In this study, we identify PRMT5 as a critical regulator of CD4+ T follicular helper cell (Tfh) responses during influenza virus infection in mice. Conditional PRMT5 deletion in murine T cells results in an almost complete ablation of both Tfh and T follicular regulatory populations and, consequently, reduced B cell activation and influenza-specific Ab production. Supporting a potential mechanism, we observe elevated surface expression of IL-2Rα on non-T regulatory effector PRMT5-deficient T cells. Notably, IL-2 signaling is known to negatively impact Tfh differentiation. Collectively, our findings identify PRMT5 as a prominent regulator of Tfh programming, with potential causal links to IL-2 signaling.

Memory of HF radar surface-current assimilation on different forecasting variables of ocean circulation models

In this study, using nudging method, the current data from a pair of HF radar along Jiangsu coast was assimilated to unstructured grid models based on FVCOM. Several experiments were conducted to examine the effect of radar data on surface velocity, elevation and sea surface salinity forecast. The results show that the gain of assimilation on surface velocity and elevation forecasts disappeared fast within a few hours, while salinity forecasts can be influenced for more than 10 days. This fast diminishing of the gain of data assimilation on current and elevation can be attributed to the fast wave propagation from elsewhere to the radar coverage area.

Experimental investigation on interaction between extreme waves and a submerged barrier

We present experimental results of a group of focused waves propagating over a submerged barrier positioned in various locations on the bottom of a flume. The study investigates the effect of the relative distance between the fixed focusing position and different barrier installation positions on the characteristics of the wave group. The surface elevation and skewness are observed to approach a crest just on top of the barrier's rear. It can be also suggested that the presence of the barrier may affect the evolution of the wave group for approximately two times of the barrier length, as indicated by the frequency component distribution. In the time domain, a small tail with mildly higher energy is generally observed when the gauge is fixed at the front surface of the barrier. It suggests that long waves at lower frequencies propagate at higher speeds, while short waves at higher frequencies are intercepted due to the barrier.

Impact of temporal beach grain size variability on aeolian sediment transport and topographic evolution in a microtidal environment

While the impact of the spatio/temporal variability of grain size on morphological beach state is reasonably well understood, relatively little is known on its impact at a scale of days/months on aeolian sediment transport. This study focuses on five short intensive wind events during which aeolian sediment transport measurements, beach surface sampling and elevation change surveys were carried out for 1 to 3 days, over a 16-month period on a microtidal beach dominated by offshore winds. Monthly observations show a high temporal variability in beach grain size in relation to the decoupling between hydrodynamic and aeolian processes, from medium sand after a marine storm and inundation of the beach, to very coarse sand after several weeks of storm-force winds. During each wind event, topographic change on the beach ranged from zero, to 0.55 m. The time scale of coarsening depended on the initial beach grain size and could be very fast when the beach was composed of medium sand (e.g. 388 μm sand changed to coarse sand of 547 μm in 40 h). In contrast, it took one month to transition from a coarse median beach grain size of 883 μm to a very coarse one of 1323 μm. This variability in grain size results in dramatically different rates of sediment flux. For example, during average wind speeds of 10 to 14 m/s the sediment flux when the beach was composed of medium sized sand ranged between 21 and 154 kg/m/h compared to 0.4 to 50 kg/m/h when the beach was composed of coarse and very coarse sized grains. Overall, this study highlights the importance of beach grain size variability on aeolian sediment transport and shows that for similar incident wind and climatic conditions aeolian sediment transport rates vary dramatically. The study demonstrates the importance of taking care when using a constant median grain size in the calculation of long-term aeolian sand transport on beaches with heterogeneous spatial and temporal beach grain size variability.

Cystic Bleb Management : A Case Report

ABSTRACT Cystic Bleb Is An Abnormal Bleb Morphology Following Trabeculectomy Procedure. This Type Of Bleb Characterized By An Elevated, Thin, And Avascular Bleb Surface. Post-Operative Bleb Evaluation Needed To Be Done Thoroughly To Recognize And Prevent Further Complication Which Can Be Sight Threatening. Several Options Of Management Include Medical Therapy And Surgical Repair. To Report The Management Of Cystic Bleb. The Study Design Is A Case Report Study, Which Was Conducted At Indonesia National Eye Centre, Cicendo Eye Hospital, Bandung, Indonesia. Subject Of The Study Was A-17-Years-Old Female That Presented With Discomfort Sensation In The Right Eye, Which Previously Has Undergone Trabeculectomy Procedure With Antifibrotic Agent Application. Ophthalmological Examination Revealed A Cystic Bleb On The Right Eye. After Medical Therapy Was Given, The Symptoms Persist, Then The Cystic Bleb Was Surgically Repaired. Follow-Up Examination Showed An Improvement Of The Patient’s Condition, Measured By No Further Complaint Of Discomfort Sensation, A Good Bleb Morphology, And A Stable Intraocular Pressure. Cystic Bleb Is One Of The Complication From Trabeculectomy Which Could Progress To Devastating Condition. Surgical Treatment Is Indicated If Symptoms Persist After Medical Management, Or In The Presence Of A Bleb Leakage. Keywords: Antifibrotic, Cystic Bleb, Trabeculectomy

Spatial and Temporal Variability in Water Quality and Phytoplankton Community Composition in Charleston Harbor

The Charleston Harbor estuary is a dynamic ecosystem draining three rivers that surround the rapidly urbanizing greater Charleston area. Projected climate change impacts include elevated sea surface temperature and local changes in water quality that will likely alter biogeochemical cycling as well as phytoplankton abundance and community composition. Partnering with the local non-profit organization Charleston Waterkeeper, surface water samples were collected from late April through October 2021 at 20 sites in the Charleston Harbor estuary system. Water quality parameters measured included sea surface temperature (SST), salinity, pH, dissolved inorganic carbon, chromophoric dissolved organic matter (CDOM), phytoplankton pigments and nitrate and phosphate concentrations. Relatively high (6—16 μM) nitrate values were observed throughout the year and the nitrate to phosphate (N:P) ratios were consistently elevated (50—200) relative to the Redfield ratio of 16. Analysis of variance indicated that the delivery of nitrate, phosphate, and CDOM into the estuary came from upriver of the Charleston Harbor. For instance, CDOM was significantly impacted by tidal stage (p < 0.05) and was negatively correlated with salinity at low salinity sites, but no correlation was observed at high salinity sites. Seasonal patterns in phytoplankton community abundance and composition were driven by changes in SST, as overall phytoplankton biomass increased with a community shift from diatoms during colder months to flagellated cells such as prasinophytes during the warmer summer months. Phytoplankton diversity was greatest during the early summer and lowest in October. This study provides a reference baseline for water quality parameters and phytoplankton community composition in an estuarine ecosystem that is changing rapidly due to dredging and climate change processes.

Bathymetry Inversion Using a Deep‐Learning‐Based Surrogate for Shallow Water Equations Solvers

AbstractRiver bathymetry is critical for many aspects of water resources management. We propose and demonstrate a bathymetry inversion method using a deep‐learning‐based surrogate for shallow water equations solvers. The surrogate uses the convolutional autoencoder with a shared‐encoder, separate‐decoder architecture. It encodes the input bathymetry and decodes to separate outputs for flow field variables. Utilizing the differentiability of the surrogate, a gradient‐based optimizer is used to perform bathymetry inversion. Two physically based constraints on the ranges of both bed elevation and slope have to be added as inversion loss regularizations to contract the solution space. Using the “L‐curve” criterion, a heuristic approach is proposed to determine the regularization parameters. Both the surrogate model and the inversion algorithm show good performance. The bathymetry inversion progresses in two distinctive stages, which resembles the sculptural process of initial broad‐brush calving and final fine detailing. The inversion loss due to flow prediction error and the two regularizations play dominant roles in the initial and final stages, respectively. The surrogate architecture (whether with both velocity and water surface elevation or velocity only as outputs) does not have significant impact on inversion result. The methodology proposed in this work, an example of differentiable parameter learning, can be similarly used in the inversion of other important distributed parameters such as roughness coefficient.

Wpływ napięcia międzyfazowego między ropą a wodą na stabilność emulsji ropnych

"The stability of crude oil emulsions sourced from wells in two distinct fields distinguished by varying physical-chemical properties was analysed. The oil taken from the wells of Muradkhanli and Balakhani fields of State Oil Company of the Azerbaijan Republic (SOCAR) has been used as the research object. Demulsification of both oils, whose composition differs in the amount of high molecular compounds, has been investigated through the static settling method for 2, 4, 6, 8, 10 and 12 hours, and the amount of residual water in the oil has been recorded. In the same time interval, the oils have been tested by adding n-hexane and phenol to them, respectively. During the experiments, it was discovered that after the addition of n-hexane, which is a saturated hydrocarbon, the surface tension force increased in both oil samples and caused the formation of water in the form of a dispersed phase in the oil, which resulted in an increase in stability. In particular, as the concentration of n-hexane in oil increased, oil emulsions became aggregative and kinetically stable. The experiments conducted involving the addition of phenol to oils revealed that an increase in the volume of phenol in the oil led to a decrease in the surface tension force at the oil-water boundary, thereby accelerating the demulsification process. Subsequently, the research extended to investigating the emulsion stability of the oil samples by adding phenol and n-hexane in varying proportions. It was observed that an increase in the phenol ratio expedited the demulsification process, whereas a higher hexane ratio weakened it. Throughout the experimental tests, fluctuations in demulsification rates were noted upon the addition of organic substances to the oil samples. Furthermore, an increase in the concentration of high molecular compounds in the oil composition resulted in elevated surface tension, posing challenges in separating the water phase from the oil. The demulsification ability of organic substances added to crude oil samples, compositions A, B and C (25% n-hexane and 75% phenol (conditional name A), 50% n-hexane and 50% phenol (conditional name B), 75% n-hexane and 25% phenol (conditional name C)) prepared on the basis of these organic substances was examined depending on the surface tension.

Assessing Chilgoza Pine (Pinus gerardiana) forest fire severity: Remote sensing analysis, correlations, and predictive modeling for enhanced management strategies

Forest fires represent a critical global threat to both humans and ecosystems. This study examines the intensity and impacts of Chilgoza (Pinus gerardiana) Pine Forest fires by using advanced remote sensing techniques comprising Normalized Burn Ratio (NBR) and Difference Normalized Burn Ratio (dNBR) analyses based on Landsat 9 datasets. The study highlights the severe effect of these fires, resulting in noteworthy losses of livestock and private properties and widespread damage to 10,156.53 acres of the Chilgoza Pine Forest. A comprehensive variable correlation analysis is conducted to gain deeper insights into the influencing factors causing forest fires. Spearman's Rank Correlation Coefficient was used to assess the association between burnt and unburnt areas and various independent factors. The analysis reveals compelling evidence of significant correlations with forest fire prevalence. This study found moderate negative (-0.532, p < 0.05) and positive (0.513, p < 0.05) correlations with elevation and Land Surface Temperature (LST), respectively, and a weak positive correlation (0.252, p < 0.05) with a Wind Speed (V). To predict forest fire susceptibility and better understand the contributing factors, three machine learning models, Random Forest (RF), XGBoost, and logistic regression, are applied to assess variable importance scores. Among the considered factors, LST is the most critical variable, with consistently high variable importance scores (100 %, 96 %, and 59 %) across all three models. Wind Speed (V) also proved influential in all models, with variable importance scores of 78 %, 83 %, and 61 % for RF, XGBoost, and logistic regression, respectively. Moreover, elevation significantly influences the frequency of forest fires, as evidenced by variable importance scores ranging from 26 % to 100 %. Comparatively, the Random Forest model outperforms XGBoost and Logistic Regression in predicting forest fire vulnerability. During the training stage, the Random Forest (RF) model achieves an impressive classification accuracy of 99.1 %, followed by XGBoost with 94.5 % and Logistic Regression with 85.6 %. On evaluation with the validation dataset, the accuracies remain promising, with RF at 96.4 %, XGBoost at 91.1 %, and Logistic Regression at 84.6 %. Based on the Random Forest model, the identified high-risk sites offer valuable insights for proactive fire management and prevention strategies. This study provides a robust predictive model and a comprehensive understanding of forest fire severity and impacts. Future research should consider climate change scenarios and account for human activities to enhance fire behavior predictions and risk assessment models.

Laboratory and non-hydrostatic modelling of focused wave group evolution over fringing reef

This paper presents physical experiments and numerical simulations to study the propagation of focused waves group across hypothetical fringing reef profiles. A wave flume is 69 m long and 1.0 m deep, and the reef cross section is made up of a reef face, a reef flat and a vertical wall. A reef crest of 0.085 m is optionally constructed on the outside to replicate the reef crown. By focusing wave trains of the JONSWAP or constant wave amplitude spectrum, the transient wave group is generated on the reef slope. Free surface elevations and flow velocity are measured over time along the flume's centreline. The focused wave process and the development of higher harmonics as a result of the nonlinear interaction over the reef face are clearly visible in the wavelet and FFT analyses of the observed free surface elevation. Low frequency wave is increasing on the reef flat while these short-period wave motions are primarily absorbed by rapid breaking on reef edge and crest. On the flat, it is discovered that reef crest has the effect of reducing short-period wave motion and increasing long-period wave motion. A numerical multi-layer non-hydrostatic wave model is employed and its ability to describe the propagation of focused wave groups over fringing reef profiles is assessed.

A novel framework to investigate wind-driven snow redistribution over an Alpine glacier: combination of high-resolution terrestrial laser scans and large-eddy simulations

Abstract. Wind-driven snow redistribution affects the glacier mass balance by eroding or depositing mass from or to different parts of the glacier’s surface. High-resolution observations are used to test the ability of large-eddy simulations as a tool for distributed mass balance modeling. We present a case study of observed and simulated snow redistribution over Hintereisferner glacier (Ötztal Alps, Austria) between 6 and 9 February 2021. Observations consist of three high-resolution digital elevation models (Δx=1 m) derived from terrestrial laser scans taken shortly before, directly after, and 15 h after snowfall. The scans are complemented by datasets from three on-site weather stations. After the snowfall event, we observed a snowpack decrease of 0.08 m on average over the glacier. The decrease in the snow depth can be attributed to post-snowfall compaction and the wind-driven redistribution of snow. Simulations were performed with the Weather Research and Forecasting (WRF) model at Δx=48 m with a newly implemented snow drift module. The spatial patterns of the simulated snow redistribution agree well with the observed generalized patterns. Snow redistribution contributed −0.026 m to the surface elevation decrease over the glacier surface on 8 February, resulting in a mass loss of −3.9 kg m−2, which is on the same order of magnitude as the observations. With the single case study we cannot yet extrapolate the impact of post-snowfall events on the seasonal glacier mass balance, but the study shows that the snow drift module in WRF is a powerful tool to improve knowledge on wind-driven snow redistribution patterns over glaciers.

The Expanding of Proglacial Lake Amplified the Frontal Ablation of Jiongpu Co Glacier since 1985

In High Mountain Asia, most glaciers and glacial lakes have undergone rapid variations throughout changes in the climate. Unlike land-terminating glaciers, lake-terminating glaciers show rapid shrinkage due to dynamic interactions between proglacial lakes and glacier dynamics. In this study, we conducted a detailed analysis of the changes in the surface elevation, velocity, and especially frontal ablation on Jiongpu Co lake-terminating glacier. The results show that the Jiongpu Co glacier has twice as much negative mass balance compared to other glaciers, and the annual surface velocity has anomalously increased (3.6 m a−1 per decade) while other glaciers show a decreased trend. The frontal ablation fraction in the net mass loss of the Jiongpu Co glacier increased from 26% to 52% with the accelerated expansion of the proglacial lake. All available evidence indicates the presence of positive feedback between the proglacial lake and its host glacier. Our findings highlight the existence of proglacial lake affects the spatial change patterns of the lake-terminating glacier. Furthermore, the ongoing enlargement of the lake area amplifies the changes associated with the evolution of the lake-terminating glacier.

Influence of Wind Flows on Surface O3 Variation over a Coastal Province in Southeast China

Surface ozone (O3) is influenced not only by anthropogenic emissions but also by meteorological factors, with wind direction being one of the most overlooked factors. Here, we combine the observational data of both O3 and wind flow to compare the variation in surface O3 with wind direction between coastal and inland regions of Fujian, a province in the southeast coast of China with complicated topography. We further conduct a numerical simulation using a global chemical transport model, GEOS-Chem, to interpret the observational results, explore the linkages between these O3 variations and wind flows, and identify the dominant processes for the occurrence of high O3 that varies with wind flows. The results from the observations over 2015–2021 suggest that, over coastal regions, surface O3 concentrations show a strong dependence on wind flow changes. On average, during the daytime, when southeasterly winds prevail, the mean of O3 concentrations reaches 83.5 μg/m3, which is 5.0 μg/m3 higher than its baseline values (the mean O3 concentrations), while the northwesterly winds tend to reduce surface O3 by 6.4 μg/m3. The positive O3 anomalies with southeasterly wind are higher in the autumn and summer than in the spring and winter. During the nighttime, the onshore northeasterly winds are associated with enhanced O3 levels, likely due to the airmass containing less NO2, alleviating the titration effects. Over inland regions, however, surface O3 variations are less sensitive to wind flow changes. The GEOS-Chem simulations show that the prevailing southeasterly and southwesterly winds lead to the positive anomaly of chemical reactions of O3 over coastal regions, suggesting enhanced photochemical production rates. Furthermore, southeasterly winds also aid in transporting more O3 from the outer regions into the coastal regions of Fujian, which jointly results in elevated surface O3 when southeasterly winds dominates. When affected by wind flows in different directions, the chemical reaction and transport in the inland regions do not exhibit significant differences regarding their impact on O3. This could be one of the reasons for the difference in O3 distribution between coastal and inland regions. This study could help to deepen our understanding of O3 pollution and aid in providing an effective warning of high-O3 episodes.

The role of extracted Patchouli residue microparticle on the mechanical and microbial properties macroalgae biopolymer

AbstractMacroalgae is extensively being used to develop eco‐friendly biopolymer or biodegradable films, but have inferior mechanical strength. This study aims to enhance the mechanical properties of seaweed films by incorporating Patchouli microparticles (PMP) derived from dried Patchouli plants (DP‐PMP) and extracted residue (ER‐PMP) from Patchouli extraction process widely use in the perfume and cosmetic industry. The PMPs, were incorporated into films forming solution at varying concentrations (1%, 3%, 5%, and 7% wt/wt) respectively. Despite similar thermal properties, the inclusion of ER‐PMP resulted in an increasing ash residue content with an increase in concentration. The optimal tensile strength was achieved with a 3% PMP loading, while higher concentrations resulted in a decline in strength. Notably, the sample containing 1% PMP demonstrated superior elasticity. Moreover, with increasing concentrations of PMPs, all samples displayed elevated surface roughness and enhanced hydrophobicity. All samples display significant antimicrobial activity against E‐coli and Salmonella sp.; however, the sample incorporating ER‐PMP showed less effect. In summary, the study suggests that DP‐PMP and ER‐PMP can serve as effective fillers to enhance the mechanical properties of seaweed biofilms, with an optimal loading of 3%. Their antimicrobial activity renders them suitable biopolymers for active packaging in food applications and other purposes.Highlights Patchouli microparticle (PMP) enhance the properties of seaweed film. Film's surface morphology and hydrophobicity changed with increase in PMP. Introduction of either PMPs increase antimicrobial properties of the film. PMP from extracted residue (ER) provide lower antimicrobial activity. 3% DP‐PMP gave the optimum properties of the film for overall attributes.

The Surface Water and Ocean Topography Mission: A Breakthrough in Radar Remote Sensing of the Ocean and Land Surface Water

AbstractThe elevations of water surfaces hold important information on the earth's oceans and land surface waters. Ocean sea surface height is related to the internal change of the ocean's density and mass associated with ocean circulation and its response to climate change. The flow rates of rivers and volume changes of lakes are crucial to freshwater supplies and the hazards of floods and drought resulting from extreme weather and climate events. The Surface Water and Ocean Topography (SWOT) Mission is a new satellite using advanced radar technology to make headway in observing the variability of the elevation of water surfaces globally, providing fundamentally new information previously not available to the study of earth's waters. Here, we provide the first results of SWOT over oceans, rivers, and lakes. We demonstrate the potential of the mission to address science questions in oceanography and hydrology.

Remotely sensed land‐cover change and floodplain disturbance following upstream‐migrating river avulsions in tropical rainforests

AbstractThe displacement of a river to a new position within its adjacent floodplain is called avulsion, and here we examine how a newly recognized style, called retrogradational avulsion, affects the surrounding floodplain in tropical rainforests using remote sensing. Retrogradational avulsions begin with a channel blockage that causes self‐propagating upstream dechannelization and flooding. While this flooding results in vegetation die‐off and floodplain sedimentation, few quantitative measurements of disturbance by retrogradational avulsions exist. Here, we first focus on land‐cover change following a single retrogradational avulsion in Papua New Guinea from 2012 to 2021. During the avulsion, the river dechannelized 892 m upstream, and the parent channel width doubled. Using maximum likelihood image classification, we observed healthy vegetation fluctuated around 4.3 km2, vegetation regrowth peaked in 2017 at 3.2 km2, dead vegetation peaked in 2013 at 2.1 km2, and visible extent of deposited sediment was greatest in 2015 at 0.44 km2. We also examined 19 other retrogradational avulsions in Papua New Guinea and South America using NDVI. The area of floodplain disturbance (i.e., vegetation die‐off and possible sedimentation) for each avulsion ranged from &lt;1 to &gt;13 km2 and scaled with the dechannelization area. Comparing our plan‐view disturbance results with FABDEM digital‐elevation data and ICESat‐2 surface elevation measurements, we hypothesize floodplain disturbance extent is a function of topographic relief. Our results also suggest that retrogradational avulsions, on average, perturb larger areas of forest compared to blowdowns, suggesting this might be an important disturbance regime that influences gap‐filling regeneration in tropical rainforests.