Variations In Water Temperature Research Articles

Concrete with clinker‐efficient cements ‐ Robustness to variations in water content and temperature

AbstractThe use of multi‐component cements (CEM II‐CEM VI), which contain main constituents other than Portland cement clinker in significant quantities, can significantly help to reduce the CO2 footprint of the cement or concrete industry. Clinker‐efficient cements (CEM II/C‐M) have been standardized in the current version of DIN EN 197‐5. In a systematic experimental program, the influence of water content variations and temperature on the robustness of concrete with clinker‐efficient cements with high contents of granulated blast furnace slag or fly ash and limestone (CEM II/C‐M (S‐LL) and CEM II/C‐M (V‐LL)) was studied. As a reference, concretes representative for construction elements used indoor (XC1) or in protected outdoor environment (XC3) with standard Portland composite cement (CEM II/A‐M) and blast furnace slag cement (CEM III/A) were investigated. The influence of variations in water content and temperature on fresh (rheological properties, bleeding) and mechanical concrete properties (compressive strength, elastic modulus) were investigated. The results obtained show similar performance and robustness of such concretes with clinker‐efficient cements compared to the reference concretes.

Gene expression patterns of Salpa thompsoni reveal remarkable differences in metabolism and reproduction near the Antarctic Polar Front.

Salpa thompsoni is an important grazer in the Southern Ocean and most abundant in the Antarctic Polar Front (APF) region. During recent decades, their distribution expanded southwards. However, it is unclear whether salps can maintain their populations in the high Antarctic regions throughout the year owing to a poor understanding of their physiological responses to changing environmental conditions. We examined gene expression signatures of salps collected in two geographically close regions south of the APF that differed in water mass composition and productivity. The observed differences in the expression of genes related to reproductive, cellular and metabolic processes reflect variations in water temperature and food supply between the two regions studied here. Our study contributes to a better understanding of the physiological responses of S. thompsoni to changing environmental conditions, and how the species may adapt to a changing environment through potential geographical population shifts under future climate change scenarios.

Seasonal and Inter-Annual Variability of Water Temperature in Petrozavodsk Bay of Lake Onega

Abstract—Based on year-round measurements of water temperature at an autonomous station (an anchored chain equipped with temperature sensors), the features of the temperature and ice regimes of the Petrozavodsk Bay of Onega Lake in modern climatic conditions were studied; the dates and duration of the main hydrological phenomena in the water area of the bay were specified. In the abnormally warm winter of 2019–2020, the water area of the Petrozavodsk Bay was not completely covered with ice for the first time in a long period of observations; in the area of the measurement station, ice fields were observed from late January to mid-March. The duration of ice-covered period in the next two winters was 3.5 and 5 months. Data were obtained on the timing of the onset and duration of the spring under-ice convection, a phenomenon that plays an important role in the thermal regime of the lake at the end of winter. It is shown that 2016, 2021 and 2022 spring under-ice convective mixing lasted 4–6.5 weeks, covering the entire water column by the end of ice period. Mixing of the water column after breaking the ice (spring homothermy) continued for another 3–4 weeks. In the spring of 2020, under-ice convection was not observed; spring overturn continued for two months from mid-March to mid-May. The dates of the upward transition of water temperature through 4°C in the years of measurements (5–19 May) were ahead of the long-term average by 2–3 weeks (end of May). Thermal stratification was established from 12 to 27 May and existed for 3–3.5 months. Complete mixing of the water mass of the bay took place in late August–early September, and then, until ice settling, the water column cooled in a state of homothermy. Immediately before ice formation, the water temperature dropped to very low values and did not exceed 0.1°С in the water column. The period with an average daily water temperature of the surface layer of the Petrozavodsk Bay above 10°C lasted from 121 to 144 days during the years of measurements.

Resolution and trade-offs in global anelastic full-waveform inversion

Summary Improving the resolution of seismic anelastic models is critical for a better understanding of the Earth’s subsurface structure and dynamics. Seismic attenuation plays a crucial role in estimating water content, partial melting, and temperature variations in the Earth’s crust and mantle. However, compared to seismic wavespeed models, seismic attenuation tomography models tend to be less resolved. This is due to the complexity of amplitude measurements and the challenge of isolating the effect of attenuation in the data from other parameters. Physical dispersion caused by attenuation also affects seismic wavespeeds, and neglecting scattering/defocusing effects in classical anelastic models can lead to biased results. To overcome these challenges, it is essential to account for the full 3D complexity of seismic wave propagation. Although various synthetic tests have been conducted to validate anelastic Full-Waveform Inversion (FWI), there is still a lack of understanding regarding the trade-off between elastic and anelastic parameters, as well as the variable influence of different parameter classes on the data. In this context, we present a synthetic study to explore different strategies for global anelastic inversions. To assess the resolution and sensitivity for different misfit functions, we first perform mono-parameter inversions by inverting only for attenuation. Then, to study trade-offs between parameters and resolution, we test two different inversion strategies (simultaneous and sequential) to jointly constrain the elastic and anelastic parameters. We found that a sequential inversion strategy performs better for imaging attenuation than a simultaneous inversion. We also demonstrate the dominance of seismic wavespeeds over attenuation, underscoring the importance of determining a good approximation of the Hessian matrix and suitable damping factors for each parameter class.

Surface Measure to Depth (SMeTD): a new low-budget system for 3D water temperature measurements for combining with UAV-based thermal infrared imagery

Characterising spatial patterns in water temperature is important for monitoring aquatic habitats and understanding physical and biogeochemical processes to support environmental management decisions. As freshwater bodies exhibit high spatial and temporal variability, high-resolution 3D temperature data are essential to understand local anomalies. The acquisition of simultaneously high spatial and temporal datasets in the field has so far been limited by costs and/or workload associated with commonly used monitoring systems.We present a new, low-cost, spatially and temporally flexible 3D water temperature monitoring system, Surface Measures to Depth (SMeTD). SMeTD can be used to provide information on the relation of water surface temperature to changes with depth, characterise water temperature in 3D and ground truth remotely sensed thermal infrared data. The systems performance was tested under laboratory conditions and under controlled conditions in the field. This revealed an accuracy comparable to established but more expensive monitoring systems. Field testing of SMeTD involved 1-min data collection of 3D water temperature for a full diurnal cycle in a lake. The 3D temperature patterns were supported by a thermal infrared image of the lakes surface. The field dataset demonstrated higher water temperatures and higher water temperature variation at the surface compared to deeper layers. SMeTD can be used to observe a broad range of hydrological processes in natural and artificial aquatic environments and help to understand processes involved with energy budgets, infiltration, limnology, or groundwater surface water exchange.

Energy Modeling of an Aquaculture Raceway

Abstract Large seasonal temperature variations in aquaculture source water leave aquaculture ponds and raceways susceptible to temperature variations leading to nonoptimal growing conditions. Such conditions may slow down the growth rate and make aquatic species vulnerable to disease and potential death, leading to economic setback for aquaculture farmers. Therefore, it is advantageous to predict the temperature of aquaculture raceways under the influence of seasonal variations and study the parameters that contribute to these variations. This allows one to develop strategies and processes to better regulate the raceway temperature to maximize its productivity. A numerical energy model was developed to simulate the temperature of water inside an aquaculture raceway, and a parametric study was conducted to investigate the influence of various key parameters on the raceway temperature. It was found that surface area and flowrate have a large effect on the raceway temperature, while depth of raceway had little effect. The largest surface area tested produced outlet temperatures and heat transfer values that were 6.2% and 76% higher, respectively, than the smallest surface area tested. Decreasing flowrate from the reference value of 43 L/s to 1 L/s resulted in an 83% increase in average outlet temperature. It was also observed that the variations in the ambient air temperature alone have negligible effect on the raceway temperature. The model was further implemented to simulate the temperature of raceways located at different geographical locations.

Species–environment relationships, clusters, and thermal ranges of fish species inhabiting boreal rivers

Understanding how key environmental factors affect fish communities is necessary for sound environmental management. Accordingly, we studied fish species–environment relationships in Finnish boreal rivers. A self-organizing map (SOM) analysis showed strong relationships between the occurrence of 18 fish species and 10 environmental variables (variance explained: 43.4%). In our logistic regression models run for each fish species, the predictive power varied from poor (AUC = 0.67–0.68) to excellent (AUC = 0.96), indicating that the responses were species-specific. The overall best predictors of the species occurrence were the local variables water depth and water temperature, and the regional variables stream size, altitude and annual mean temperature. Our results on fish assemblage types (clusters), identified by SOM, and co-occurrence of fish species, discovered by a hierarchical cluster analysis, reveal insights into the structure of the river fish assemblages. Moreover, our results suggest that the stream size contributes to thermal ranges in which each species is able to occur, which has relevance to predicting the impacts of climate change on riverine fish.

Effects of the Last Deglaciation climate warming on hydrate dissociation in the northern South China Sea

Sea level and bottom water temperature variations caused by the Last Deglaciation climate warming impacted the stability of marine hydrates. In order to examine their influence on hydrate dissociation in the northern South China Sea (SCS), we conducted simulations to track the evolution of hydrate saturation and hydrate occurrence zone since the Last Deglaciation in the Dongsha Area, Shenhu Area, Xisha Area and Qiongdongnan Area. The amount of methane generated and subsequently released into seawater and atmosphere was also evaluated within the four areas. The simulation revealed the following results: (1) Hydrate dissociation induced by variations in sea level and bottom water temperature was observed in the Dongsha Area, Xisha Area and Qiongdongnan Area, but not in the Shenhu Area. (2) The water depth at which hydrate dissociation occurred ranged between 480 and 720 m, encompassing a hydrate dissociation area of approximately 1.54 × 1010 m2. This accounted for 6.68% of the northern South China Sea Area. (3) Since the Last Deglaciation, an estimation of 3.08 × 108–1.48 × 1010 m3 hydrates have dissociated, resulting in the release of 5.05 × 1010–2.43 × 1012 m3 methane. The generated methane migrated through the overlying sediments by means of central migration mode. 9.9 × 109–4.76 × 1011 m3 methane entered into the seawater, which will result in the formation of a weak acid affecting the marine environment. Meanwhile, 2.02 × 108–9.72 × 109 m3 methane entered into the atmosphere, which leads to an increase in greenhouse gas concentrations.

Seasonal Evolution of Stable Thermal Stratification in Central Area of Lake Ladoga

The complete climatic courses of the parameters of stable thermal stratification for the central part of Lake Ladoga, the largest European lake, are presented on the basis of empirical relationships, taking into account the physical processes governing water temperature variations. For the first time, the seasonal cycle of the surface water temperature, the temperature and the depth of the thermocline, and the hypolimnion temperature are calculated using the vertical profiles of the temperature obtained from the central area of Lake Ladoga. Temperature data are used for the period of in situ observations from 1897 to the present. The proposed functional forms of the temporal temperature cycle and the course of thermocline’s boundaries deepening are useful for examination and simulation of the heat vertical transport from air to water. Approximation curves for the parameters of heating and cooling periods were developed with high significant determination coefficients. Time dependencies of the climatic rates of change in water temperature and the depth of the thermocline boundaries were determined from the onset of stable stratification to its dissipation. The highest rate of water temperature change in the heating stage takes place in late June–early July, which at the water surface, is 0.32 °C/day, while in the thermocline layer, it is 0.18 °C/day. The peak velocity during the cooling stage at the surface occurs in late August–early September and is 0.14 °C/day, whereas in the thermocline, it is 0.08 °C/day and takes place between September and early October. During the period of heating, the deepening parameters of the thermocline layer do not fluctuate very much, only within the range of 0.1–0.3 m/day. During the cooling period, under the influence of free convection, rates increase drastically. The maximum rates of deepening during the period of full autumn mixing reach 1.8 m/day. When the autumn overturn occurs, the epilimnion thickness equals the bottom depth, and the bottom temperature reaches its maximum during the annual cycle. Climatic norms of the stratification parameters against which it is necessary to assess climate change are calculated.

The Present-Day Structure of the Temperature and Current Fields in Lake Sevan

Long-term features of the vertical and horizontal structure of water temperature field in Lake Sevan are discussed. It is shown that the climate warming has led to an increase in epilimnion temperature in Bol’shoi Sevan in July by 2.0‒3.0°C. The increase in water temperature in hypolimnion was not greater than 1.1°C. In autumn (October), the epilimnion became 1.2°C warmer, while hypolimnion temperature practically has not changed on the average over years. Temperature fields were used to calculate the density currents in summer and autumn periods. A dominating cyclonic water circulation was revealed all over the lake, confirmed by chlorophyll distribution by satellite image data. In the case of large horizontal gradients of water density, the flow velocity can reach 50 cm/s. Autonomous buoy stations revealed a wide range of water temperature variations due to internal waves of different nature. The reversible vertical mixing of water mass by internal waves plays an important role in the distribution of nutrients and plankton within the water mass. The water level rise by ~3 m, unlike it drop by 1981 by 18.48, has not caused any significant changes in lake hydrological regime.

Two centuries of southwest Iceland annually-resolved marine temperature reconstructed from Arctica islandica shells

Iceland's exposure to major ocean current pathways of the central North Atlantic makes it a useful location for developing long-term proxy records of past marine climate. Such records provide more detailed understanding of the full range of past variability which is necessary to improve predictions of future changes. We constructed a 225-year (1791–2015 CE) master shell growth chronology from 29 shells of Arctica islandica collected at 100 m water depth in southwest Iceland (Faxaflói). The growth chronology provides a robust age model for shell oxygen isotope (δ18Oshell) data produced at annual resolution for 251 years (1765–2015 CE). The temperature reconstruction derived from δ18Oshell shows coherence with May–October local surface temperature records and sea surface temperatures in the North Atlantic region, suggesting it is a useful proxy indicator of water temperature variability at 100 m depth within Faxaflói. Field correlations between the shell-based records and gridded sea surface temperature data reveal strong positive correlations between the 1-year lagged shell growth and temperatures within the subpolar gyre post-1972, suggesting a delayed influence of subpolar gyre dynamics on ecological indicators in southwest Iceland in recent decades. However, the shell growth chronology and δ18Oshell record generally show relatively weak and insignificant correlations with larger region climate indices including the Atlantic Multidecadal Variability, North Atlantic Oscillation, and East Atlantic pattern. Therefore the interannual variations in the newly produced shell-based records appear to reflect more local to regional dynamics around southwest Iceland than large-scale modes of climate variability.

基于热传输与水混合的持续监测和数值模拟的泉水温度变异性解释: 以波兰南部Pieniny山脉Czarny Potok泉水为例

AbstractA numerical model of heat conduction and water mixing was developed, enabling a quantitative description of water temperature variability at a spring outflow. The study examined the Czarny Potok spring, located in the Pieniny Mountains of southern Poland, which was the subject of a 4-year series of water temperature observations. The presented model describes the soil and water environment in the immediate vicinity of the spring, assuming that the spring water temperature is shaped by the mixing of water flowing through the shallow zone that experiences seasonal fluctuation and the deeper neutral zone. It was also assumed that the conductive heat flow in the tested medium is conditioned by seasonal heating and cooling of the land surface. The thermal diffusivity of the bedrock was calculated on the basis of the phase shift and the attenuation of thermal amplitude at different depths, based on long-term monitoring of soil temperature. The heat conduction and water mixing models enabled calculation of the water temperature at the outflow. The obtained results are close to the empirical spring water temperatures. The estimated mean error was 0.075 °C and the mean absolute error was 0.188 °C. The results of the calculations suggest that the tested spring is recharged primarily by water flowing through the seasonal fluctuation zone (75%), while the remaining 25% captures a deeper circulation system associated with the neutral zone.

Reconstruction of annual and seasonal variations in water temperature in the Haute-Dronne River of southwest France based on δ18O records of freshwater pearl mussel shells (M. margaritifera), and its palaeoenvironmental implications

The aragonitic shells of freshwater pearl mussels (Margaritifera margaritifera) contain annual growth increments, whose composition reflect the geochemistry of the river water and bivalve metabolism. The wide geographic distribution and the long lifespan of M. margaritifera coupled with a previously established relationship between the δ18O values of their shells and river temperature means this taxon is a potentially important environmental archive; such freshwater proxies are currently limited in both space and time. In this paper, we investigate the relationship between δ18O values and both in situ and modeled river temperature (2007–2015) for a population of M. margaritifera living in the Haute-Dronne River (southwest France). Our δ18O data permit the reconstruction of seasonal temperature variations in the river. Sclerochronology reveals that shells also record seasonal patterns and produce winter growth increments, contrary to other investigations carried out on the same mussel species from northern Europe where low winter temperatures (below 5 °C) interrupt shell growth. The presented calibration for M. margaritifera and host river temperature offers the potential for reconstructing palaeoenvironmental conditions based on fossil specimens of the same species. Such reconstructions may improve our understanding of past continental climate and help calibrate regional palaeoclimate models.

A Comparison of Fish Ponds in the Lailan, Daqoq, Yayji, and Sarkaran Areas in Terms of Temperature and Ph

Food security and increased fish production are critical issues for many countries, including Iraq, where many rely on fish as a primary source of protein and nutrition. To achieve this goal efficiently and sustainably, it is essential to understand and monitor the environmental factors that affect the success of fish farming. This study analyzed water temperature and pH levels in several fish ponds in the Lailan, Daqoq, Yayji, and Sarkaran regions of Iraq. Monthly and spatial variations in these environmental factors were studied over several months in the year, allowing an understanding of their impact on the aquatic environment and fish health. The results showed monthly and spatial variations in water temperature and pH levels among the studied regions. These results were compared with international standards for fish water quality, and it was concluded that most of the ponds met these standards, suggesting the potential for improving fish farming practices and increasing production. Furthermore, the study highlighted the importance of achieving a balance in water temperature and pH levels to maintain fish health and enhance the success of farming operations. These findings can contribute to agricultural sustainability, provide food resources for local communities, and achieve food security in the region. Understanding the relationship between water temperature and pH levels and fish health and productivity is a crucial step towards enhancing the fish farming sector in Iraq and meeting the increasing food needs of the population [1].

A Comparison of Fish Ponds in the Lailan, Daqoq, Yayji, and Sarkaran Areas in Terms of Temperature and Ph

Food security and increased fish production are critical issues for many countries, including Iraq, where many rely on fish as a primary source of protein and nutrition. To achieve this goal efficiently and sustainably, it is essential to understand and monitor the environmental factors that affect the success of fish farming. This study analyzed water temperature and pH levels in several fish ponds in the Lailan, Daqoq, Yayji, and Sarkaran regions of Iraq. Monthly and spatial variations in these environmental factors were studied over several months in the year, allowing an understanding of their impact on the aquatic environment and fish health. The results showed monthly and spatial variations in water temperature and pH levels among the studied regions. These results were compared with international standards for fish water quality, and it was concluded that most of the ponds met these standards, suggesting the potential for improving fish farming practices and increasing production. Furthermore, the study highlighted the importance of achieving a balance in water temperature and pH levels to maintain fish health and enhance the success of farming operations. These findings can contribute to agricultural sustainability, provide food resources for local communities, and achieve food security in the region. Understanding the relationship between water temperature and pH levels and fish health and productivity is a crucial step towards enhancing the fish farming sector in Iraq and meeting the increasing food needs of the population [1].

Influence of Some Abiotic Factors on the Diatom Densities in the Mezam River (Bamenda, North-West Cameroon)

Wetlands of the city of Bamenda are characterized by intense agricultural activities. The resulting consequences are aquatic pollution. The management of these wetlands requires the study of the animal and plant communities found there. Diatoms are known to be good markers of environmental change. The aim of the study was to determine the influence of some abiotic parameters on the diatom densities of the Mezam river. The study was conducted from January to December 2022. Some physicochemical parameters were measured in situ. Water samples were collected and transported to the laboratory for the measurement of nitrates, total phosphorus, carbon dioxide and biological oxygen demand. The diatoms were sampled and analyzed in the laboratory. Factorial axis 2 (0.47%) of correspondence factor analysis opposed the positive variables (conductivity, total dissolved solids and salinity) to the negative variables (water temperature, pH, nitrates, total phosphorus, oxidability, carbon dioxide and alkalinity). Study sites showed a mineralization gradient going from upstream (Site 1) to downstream (Site 3). Total species richness amounted to 4 classes divided in 18 families, 21 genera and 43 species. The most dominating family was Naviculaceae with 10 species. Multiple component analysis showed, in different study sites, the correlation between chemical parameters and density of different genera. The more the site was polluted, the more the density of Navicula, Tabellaria, Melosira and Coscinodiscus increased. On the contrary, the less the site was polluted, the more the density of Cyclotella, Gomphonema, Cocconeis, Gyrosigma, Synedra increased. These results showed that the distribution of diatoms in the different study sites was influenced by a set of conditions related to physicochemical parameters, but more on their densities.

Application of a soil temperature model for simulating the effect of dis-trict heating pipes on drinking water pipelines

According to Dutch legislation the drinking water temperature is required to be below 25°C at the tap to meet legionella prevention [1]. This requirement possibly limits the storage of heat in the subsoil and the transport of heat through pipelines. In order to asses the impact of heat transport pipelines on the drinking water temperature in adjacent drinking water pipelines, a soil temperature model was developed. This coupled micro-climate [2] and heat transport model relates atmospheric conditions to the temperature distribution in the sub-surface [3]. The subsurface part of the model is based on a finite element discretization of the transient heat conduction equation in a single phase material. The coupling of the subsurface part of the model with atmospherical part of the model requires that the sensible heat flux, the latent heat flux, net radiation and the subsurface heat flux are in equilibrium at the land surface. Simulation periods of a number of years are discritized in time steps of one hour. The model is validated by comparing the model results with a large number of field measurements in the Dutch city Rotterdam-Kralingen [3].
 The validated model is used to predict the drinking water temperature in transport, primary and secondary pipeline networks. The transport networks supply heat and water to the primary networks. Primary networks distribute their heat and water to secondary networks that transport it to buildings.
 with and without heating pipelines parallel to drinking water pipelines, with a limited flow of drinking water. The inner diameter of the heat supply and return pipelines, which are usually located close to each other, is 160.3 mm. The heat supply temperature is 90°C and the return temperature is 70°C. The inner diameter of the drinking water pipelines is 152 mm. The heat transport pipelines consist of an inner steel pipe with a wall thickness of 4 mm, a PUR isolation of 56 mm and a PE sleeve of 4 mm. The finite element discretization captures the geometry of the insulated pipeline and associated effective thermal properties. Drinking water pipelines have a PVC wall with a thickness of 4 mm. The drinking water pipeline cover depth is 1.00 m, the distance in between the drinking water pipeline and heat return pipeline is 0.75 m and the soil cover of the heat supply pipelines is 1.00 m. Tiles cover a dry sandy soil for which the specific heat capacity is 800 J/kgK, the thermal conductivity is 1.6 W/mK and the density of the soil is 1600 kg/m3. The figure shows a seasonal variation of the drinking water temperature of 13.8°C and an increase of the drinking water temperature due to the presence of the heat transport pipelines of 2.0°C, which is almost constant throughout the year. The maximum drinking water temperature is found in August and amounts to 23.8°C if the heat pipelines are absent and 25.8°C if they are present.
 Table 1 presents the results of a study with variation of the drinking water pipeline soil cover, the distance in between drinking water pipeline and heat return pipeline and the soil cover of the heat supply pipelines. Based on this table decisions can be made on the type of construction and the effect of the heat transport pipelines on adjacent drinking water pipelines.
 The table shows that the cover depth of the drinking water pipeline strongly influences the increase of the drinking water temperature due to atmospheric conditions. A decrease of the soil cover from 2.00 m to 0.75 m raises the maximal temperature by 4.2°C. The presence of the heat transport pipelines increases the temperature of the drinking water by 1.7°C for the case of a small cover depth and 2.1°C for a large cover depth. A decrease of the distance in between the drinking water pipeline and the heat return pipeline from 2.5 m to 0.25 m raises the maximal drinking water temperature by 2.6 °C. The calculation results show that the drinking water temperature is not sensitive to the proposed cover depth variation of the heat supply pipelines. The computational results for all networks considered, are collected in an expert tool that can be accessed via: https://www.tkiwatertechnologie.nl/projecten/opwarming-van-drinkwater/.

Predicting micropollutant fate during wastewater treatment using refined classical kinetic model based on quantitative monitoring in multi-metropolitan regions of South Korea

This study aimed to implement an extensive prediction model for the fate of micropollutants (MPs) in wastewater treatment plants (WWTPs). Five WWTPs equipped with seven different biological treatment processes were monitored from 2020 to 2022 with three to four sampling events in each year, and 27 datasets for 20 MPs were collected. Among these datasets, 12 were used to investigate the behavior and fate of MPs in WWTPs in South Korea. Metformin, acetaminophen, caffeine, naproxen, and ibuprofen were the MPs with the highest influent concentrations (ranging from 3,933.3–187,637.0 ng L−1) at all WWTPs. More than 90% of MPs were removed by biological treatment processes in all WWTPs. The Kruskal-Wallis test verified that their efficacy did not differ statistically (p-value > 0.05). Meanwhile, to refine the performance of the prediction model, this study optimized the biodegradation rate constants (kbio) of each MP according to the variation of seasonal water temperature. As a result, compared to the original prediction model, the mean difference between the actual data and predicted results (MEAN) decreased by 6.77%, while the Nash-Sutcliffe efficiency (NSE) increased by 0.226. The final MEAN and NSE for the refined prediction model were calculated to be 5.09% and 0.964, respectively. The prediction model made accurate predictions, even for MPs exhibiting behaviors different from other cases, such as estriol and atrazine. Consequently, the optimization strategy proposed in this study was determined to be effective because the overall removal efficiencies of MPs were successfully predicted even with limited reference datasets.

Hymenaea stignocarpa Mart. ex Hayne growth–climate relationships are regulated by soil water saturation in Cerrado-Pantanal ecotone

The expected intensification of the dry season, and concentration of rainfall during the wet season, can disrupt tree growth and regional biodiversity in the Cerrado-Pantanal transition zone. Thus, this study aims to assess the climatic responses of Hymenaea stigonocarpa tree growth, a common tree species in this region. Incremental cores were collected at breast height (ca. 1.3 m) from 67 trees to construct a dendrochronological series to correlate annual growth with local meteorological variables and large-scale atmospheric circulation indices from the Pacific and Atlantic Oceans. Significant positive correlations were observed between tree growth and the Pacific Ocean indices. Maximum and average air temperatures of the previous dry season negatively influenced growth, while precipitation at the beginning of the growth season (November) positively influenced growth. Tree growth was not correlated with temperature or rainfall during the wet season. However, at the end of the wet season (February), tree growth was negatively correlated with air temperature and positively correlated with rainfall, but the relationship shifted in the next month (March) suggesting that soil water saturation reduced growth. Our results indicate that dendrochronological studies of H. stignocarpa are useful for assessing the environmental change on the Cerrado-Pantanal ecotone. Furthermore, variations in water availability and temperature associated with changes in large-scale oceanic circulation and local meteorological conditions will impact the growth dynamics of this important Cerrado tree species.

Feasibility of aquaculture cultivation of elkhorn sea moss (Kappaphycus alvarezii) in a horizontal long line in the Tropical Eastern Pacific

Seaweed aquaculture has become a profitable and an attractive alternative of cultivation thanks to its quick biomass production for food, feed, and other non-food applications. In addition, the ecosystem services generated by seaweed cultivation towards carbon fixation represents a more sustainable solution to the ocean’s acidification. The growth of elkhorn sea moss (Kappaphycus alvarezii) was evaluated in three plots with 200 propagules during a period of 70 days in a floating raft system covered by a fishing net underneath. Initial weight of propagules was 159.3 ± 12.74 g in wet biomass and 15.3 ± 1.43 g in dry biomass and were sampled up to 19 days (in the lag growth phase; period I), up to 33 days (in the exponential growth phase; period II) and up to 70 days (in the stationarity growth phase; period III). The variations of sea surface water temperature, salinity, turbidity (Secchi depth), total ammonium, nitrites, nitrates, and phosphate were determined. The growth increase was more evident in the exponential phase II when a dry biomass of 28.0 ± 2.48 (1153.3 ± 6.25 g in wet mass) was reached, more than 7 times the biomass of propagules with an average daily growth rate of 15.2% g.day–1. The carrying capacity of the zone was estimated at 86.2% in the area where 53 cultivation units would be projected. The economic analysis presented a financial feasibility with a net profit of 19% over the projected income and an IRR of 16.5%, recovering the investment in an estimated period of 4.3 years. We recommend to continue with larger-scale studies to optimize the cultivation of K. alvarezii in the study area.