Internal Cycling Research Articles

Simulating the effects of aquatic avifauna on the Phosphorus dynamics of aquatic systems

Many freshwater ecosystems throughout the world support a high number of waterbirds. Nutrient from droppings of these waterbirds may serve as an important source of nutrients to those systems. Previous works suggest that excess nutrients from waterbirds may lead to eutrophication. The excess nutrients also may induce nuisance growth of aquatic weeds in shallow lakes. However, the aquatic weeds serve as an important food for some avian species. The main objective of this work is to study how the waterbirds affect the dynamics of the aquatic ecosystem through a process-based modelling approach.To understand this, a lake with negligible anthropogenic nutrient influx and the high winter-avian congregation is taken as study site. A process-based dynamic ecological model with six state variables has been developed. Phosphorus (P) is taken as model currency since it is the limiting nutrient in most shallow and present in high concentration in the dropping of waterbirds. Before the model calibration, sensitivity analysis is performed with the data collected during the first year of study. Model is validated with the data collected during the second year of study.As per the model, P from the waterbird guano comprises 98.32% of P input to the lake. Parameters affecting the water-sediment exchange of P are most sensitive. P content in zooplankton is the most sensitive state variable. Nutrient budget analysis reveals that internal cycling of the nutrient is the main pathway to sustain productivity in the system. So far, no process-based modelling has been done on the impact of dropping of waterbird on nutrient dynamics of the aquatic system. This kind of model will be helpful to handle problems like eutrophication and macrophyte overgrowth due to eutrophication.

Моделирование замкнутого внутреннего топливного цикла ядерного реактора

Моделирование замкнутого внутреннего топливного цикла ядерного реактора

Complex dynamics of water quality mixing in a warm mono-mictic reservoir.

Cycling of water quality constituents in lakes is affected by thermal stratification and homo-thermal conditions and other factors such as oligotrophication, eutrophication, and microbial activities. In addition, hydrological variability can cause greater differences in water residence time and cycling of constituents in man-made lakes (reservoirs) than in natural lakes. Thus, investigations are needed on vertical mixing of constituents in new impounded reservoirs, especially those constructed to supply domestic water. In this study, sampling campaigns were conducted in the Sabalan reservoir, Iran, to investigate vertical changes in constituent concentrations during the year in periods with thermal stratification and homo-thermal conditions. The results revealed incomplete mixing of constituents, even during cold months when the reservoir was homo-thermal. These conditions interacted to create a bottom-up regulated reservoir with sediment that released settled pollutants, impairing water quality in the Sabalan reservoir during both thermal stratification and homo-thermal conditions. Analysis of total nitrogen and total phosphorus concentrations revealed that the reservoir was eutrophic. External pollution loads, internal cycling of pollutants diffusing out from bottom sediments, reductions in inflow to the reservoir, and reservoir operations regulated vertical mixing and concentrations of constituents in the Sabalan reservoir throughout the year.

Circadian Rhythms of the Hypothalamus: From Function to Physiology.

The nearly ubiquitous expression of endogenous 24 h oscillations known as circadian rhythms regulate the timing of physiological functions in the body. These intrinsic rhythms are sensitive to external cues, known as zeitgebers, which entrain the internal biological processes to the daily environmental changes in light, temperature, and food availability. Light directly entrains the master clock, the suprachiasmatic nucleus (SCN) which lies in the hypothalamus of the brain and is responsible for synchronizing internal rhythms. However, recent evidence underscores the importance of other hypothalamic nuclei in regulating several essential rhythmic biological functions. These extra-SCN hypothalamic nuclei also express circadian rhythms, suggesting distinct regions that oscillate either semi-autonomously or independent of SCN innervation. Concurrently, the extra-SCN hypothalamic nuclei are also sensitized to fluctuations in nutrient and hormonal signals. Thus, food intake acts as another powerful entrainer for the hypothalamic oscillators’ mediation of energy homeostasis. Ablation studies and genetic mouse models with perturbed extra-SCN hypothalamic nuclei function reveal their critical downstream involvement in an array of functions including metabolism, thermogenesis, food consumption, thirst, mood and sleep. Large epidemiological studies of individuals whose internal circadian cycle is chronically disrupted reveal that disruption of our internal clock is associated with an increased risk of obesity and several neurological diseases and disorders. In this review, we discuss the profound role of the extra-SCN hypothalamic nuclei in rhythmically regulating and coordinating body wide functions.

Responses of soil gross nitrogen transformations to three vegetation restoration strategies in a subtropical karst region

AbstractInvestigation of soil internal nitrogen cycles is useful for unravelling the mechanisms responsible for soil nitrogen availability change. Here, gross nitrogen transformations were investigated in a subtropical karst area after 16 years of vegetation restoration. The experiment included four treatments with one control and three restoration strategies, that is: (i) maize‐soybean rotation field (CR, control); (ii) restoration with Toona sinensis (TS); (iii) restoration with Guimu‐1 hybrid elephant grass (GG, Pennisetum americanum (L.) Leeke × Pennisetum purpureum Schumach); and (iv) restoration with Guimu‐1 hybrid elephant grass and Zenia insignis as a mixture (ZG). Soil NH4+ and NO3− responded differentially to three restoration strategies, resulting in no significant change of total inorganic N content following vegetation restoration. Gross nitrogen mineralization (GNM) rate increased by 124.0%, 96.8%, and 60.3% in TS, GG, and ZG, respectively, relative to CR (2.88 ± 0.05 mg N kg−1 d−1). The strongest explanatory variable was microbial biomass carbon for both GNM (R2 = 0.82) and gross nitrification (R2 = 0.66). Dissimilatory NO3− reduction to NH4+ (DNRA) rate in TS or ZG, which was significantly greater than that in CR, was significantly correlated with SOC: NO3− ratio (R2 = 0.61), implying that DNRA was limited by SOC availability. Gross NH4+ immobilization rate, which was highest in GG, and lowest in CR, was best predicted by carbon to nitrogen ratio (R2 = 0.65). However, gross NO3− immobilization rate could not be well predicted by the measured soil properties. Our results suggest that vegetation restoration especially TS significantly enhanced soil N availability as reflected by gross N mineralization rate.

Contributions of external nutrient loading and internal cycling to cyanobacterial bloom dynamics in Lake Taihu, China: Implications for nutrient management

AbstractHarmful cyanobacterial blooms (CyanoHABs) are linked to increasing anthropogenic nitrogen (N) and phosphorus (P) inputs. However, CyanoHABs in many large lakes continue despite extensive abatement efforts, mostly focused on external P loading. Internal nutrient cycling can modify nutrient availability and limitation; thus, understanding the relative importance of external vs. internal nutrient loading is essential for developing effective mitigation strategies for CyanoHABs. We estimated long‐term nutrient budgets for Lake Taihu, China, from mass balance models using extensive monitoring of input and output nutrient data from 2005 to 2018 to quantify contributions from internal nutrient loading. The nutrient mass balance showed that 9% and 63% of annual external N and P inputs, respectively, were retained in the lake. Denitrification removed 54% of external N loading and can thus help explain rapid decreases in lake N concentrations and summer N limitation. Water columnregeneration can help sustain CyanoHABs over the short term and contributed 38–58% of potentialdemand for summer‐fall,Microcystis‐dominated blooms. Internal P release contributed 23–90% of CyanoHABs P demand, although Taihu was a net P sink on an annual scale. Our results show that internal nutrient cycling helps sustain CyanoHABs in Taihu, despite reductions in external nutrient inputs. Furthermore, N is leaving the lake faster than P, thereby creating persistent N limitation. Therefore, parallel reductions in external N loading, along with P, will be most effective in reducing CyanoHABs and accelerate the recovery process in this and other large, shallow lakes.

Anthropogenic Iron Deposition Alters the Ecosystem and Carbon Balance of the Indian Ocean Over a Centennial Timescale

AbstractPhytoplankton growth in the Indian Ocean is generally limited by macronutrients (nitrogen: N and phosphorus: P) in the north and by micronutrient (iron: Fe) in the south. Increasing atmospheric deposition of N and dissolved Fe (dFe) into the ocean due to human activities can thus lead to significant responses from both the northern and southern Indian Ocean ecosystems. Previous modeling studies investigated the impacts of anthropogenic nutrient deposition on the ocean, but their results are uncertain due to incomplete representations of the Fe cycling. This study uses a state‐of‐the‐art ocean ecosystem and Fe cycling model to evaluate the transient responses of ocean productivity and carbon uptake in the Indian Ocean, focusing on the centennial time scale. The model includes three major dFe sources and represents an internal Fe cycling modulated by scavenging, desorption, and complexation with multiple, spatially varying ligand classes. Sensitivity simulations show that after a century of anthropogenic deposition, ecosystem responses in the Indian Ocean are not uniform due to a competition between the phytoplankton community. In particular, the competition between diatom, coccolithophore, and picoplankton alters the balance between the organic and carbonate pumps in the Indian Ocean, increasing the carbon uptake along 50°S and the southeastern tropics while decreasing it in the Arabian Sea. Our results reveal the important role of ecosystem dynamics in controlling the sensitivity of carbon fluxes in the Indian Ocean under the impact of anthropogenic nutrient deposition over a centennial timescale.

Nitrogen -addition accelerates phosphorus cycling and changes phosphorus use strategy in a subtropical Moso bamboo forest

Ecosystem-level effects of increasing atmospheric nitrogen (N) deposition on the phosphorus (P) cycle and P use strategy are poorly understood. Here, we conducted a seven year N-addition experiment to comprehensively evaluate the effects of N deposition on P limitation, cycling, and use strategy in a subtropical Moso bamboo forest. N addition significantly increased foliar litterfall by 4.7%–21.7% and subsequent P return to the soil by 49.0%–70.1%. It also increased soil acidity, acid phosphatase activity, and soil microbial biomass P, which substantially contributed to a significantly increased soil P availability and largely alleviated the P limitation. This resulted in a significant decrease in the foliar P-resorption efficiency and the abundance and colonization of arbuscular mycorrhizal fungi. Our results indicate that N deposition can reduce plant internal cycling while enhancing ecosystem-scale cycling of P in Moso bamboo forests. This suggests a shift in P use from a ‘conservative consumption’ strategy to a ‘resource spending’ strategy. Our findings shed new light on N deposition effects on P cycle processes and P use strategy at the ecosystem scale under increasing atmospheric N deposition.

Transboundary air pollution reduction rapidly reflected in stream water chemistry in forested catchment on the sea of Japan coast in central Japan

Since the 1980s, Japan has been affected by transboundary air pollution from the Asian continent due to northwesterly seasonal winds in the winter. However, after peaks in 2006 and 2011/2012, sulfur dioxide (SO2) and nitrogen oxide (NOx) emissions began decreasing, respectively. To assess the biogeochemical response of forest ecosystems to the changing atmospheric deposition, flux observations of rainfall outside forest canopies (RF), throughfall and stemflow (TF + SF), and stream water (SW) chemistry were conducted in a Japanese cedar plantation in Kajikawa (KJK) on the Sea of Japan coast in central Japan. Fluxes of S and N by RF and TF + SF at KJK significantly decreased during the observation period (2002–2018). The non-sea salt sulfate (SO42−) flux by TF + SF peaked in 2006/2007 and decreased thereafter, which likely reflected the S emission trends. Accordingly, SO42− concentrations in SW at KJK decreased with increasing alkalinity. Similar decreases in SO42− concentrations beginning in 2006, 2007, and 2008 were observed at eight monitoring lakes in Japan. Thus, the SW chemistry at KJK and possibly that of Japanese lakes were sensitive to atmospheric S deposition reductions. However, as of late, the net S export at KJK has been increasing, exhibiting budget discrepancies in 2014/2015 and 2017/2018. Sulfur isotopic analysis suggested that the S deposited from the atmosphere was retained/cycled in the forest before it was gradually discharged into SW. Thus, a slightly weakened reaction of the output due to the internal cycle and residual effects of previous years may have caused the S budget discrepancies. The nitrate (NO3−) concentration in the SW at KJK has also been continuously increasing. N deposition and other factors, such as the maturation of the planted trees, may play an important role in NO3− leaching in plantations.

Responses and drivers of leaf nutrients and resorption to nitrogen enrichment across northern China’s grasslands: A meta-analysis

A meta-analysis was preformed to reveal how environmental and experimental factors alter the effects of N enrichment on the concentrations and stoichiometry of N and P in both mature and senesced foliage and nutrient resorption, with published studies from Chinese grasslands. N enrichment, when averaged across the studies, significantly increased the mature leaf N, P and N:P by 27.89%, 2.55% and 20.85%, respectively. The N, P and N:P ratio for senesced foliage under N enrichment increased by 41.35%, 3.28% and 20.11%, respectively, but N enrichment significantly decreased the leaf N resorption efficiency (NRE) and P resorption efficiency (PRE) by 6.85% and 3.41%, respectively. They were significantly controlled by the rates of addition of N, humidity index and the ratio of N addition rates to ambient N deposition, which suggested that ambient N deposition can indirectly influence plant internal nutrient cycling in this system. The effects of N enrichment on the N, P, stoichiometry and nutrient resorption in plants varied greatly among the types of grassland. In addition, the rates of N addition, forms of N application, experimental duration and application frequency of N had different effects on the leaf nutrient status. Specifically, the response of a critical threshold value of leaf P to N addition is 50–100 kg N ha−1 year−1, at which range with a shift from negative to positive impacts. Moreover, the addition of N significantly changed N and P coupling in mature leaves but not of senesced leaves, which were primarily regulated by N enrichment impacts on nutrient resorption. Our findings suggest that N enrichment significantly affected the status of leaf nutrients and then altered plant internal nutrient cycling across the grasslands of northern China.

Decoupling of nitrogen and phosphorus in dominant grass species in response to long-term nitrogen addition in an Alpine Grassland in Central Asia

Increased nitrogen (N) availability induced by fertilizer use, rapid urbanization, and livestock cultivation has important effects on the biogeochemical cycles of plant N and phosphorus (P). Knowledge of the long-term N enrichment effects on the biogeochemical cycling of N and P via plant ecological stoichiometry and nutrient resorption remains limited. Nutrient resorption plays an important role in the plant nutrient economy and nutrient cycling. A three-year field experiment was performed to test the effects of N addition on leaf nutrient resorption of two dominant grass species (Leymus tiansecalinus and Festuca ovina) from an 11-year grassland experiment involving four N levels (0, 30, 90, and 150 kg N ha−1 year−1) in an alpine grassland of Tianshan Mountains in northwestern China. Nitrogen addition significantly increased aboveground biomass (AGB) and soil N availability. The N concentrations and N:P ratio in mature and senesced leaves consistently increased with increasing N across all three years. The P concentrations in mature and senesced leaves notably decreased with increasing N. The N addition resulted in decreased N resorption efficiency (NRE) and increased P resorption efficiency (PRE). The divergent responses of plant N and P resorption and N:P ratios resulted in the decoupling of the plant internal nutrient cycles for both grass species, attributed to increased soil N availability and nonsignificant effects on soil available P caused by N addition. In addition, the N:P resorption ratios were negatively correlated with increasing N levels, suggesting different sensitivities of plant N and P to N addition. The aboveground production of both grass species was positively correlated with PRE and negatively correlated with NRE. Under the background of the currently high and steadily increasing atmospheric N deposition, the imbalance of plant nutrient cycling will likely alter plant community compositions and subsequent litter decomposition, ultimately affecting ecosystem stability and function.

Financial, Absorption and Business Cycles in Selected African Countries

This study examines the relationship between internal absorption, financial and business cycles in selected African countries. Using Markov’s regime change model on data for the period 1960-2018. The data was obtained from the online version of the World Bank’s World Development Indicators. The results show that the Keynesian or monetary effects on each phase of the business cycle is different in the various countries. During the phase of economic expansion, the rate of evolution of consumption and gross fixed capital formation accelerate the expansion trend. During the phase of recession, these variables play a stabiliser role by moderating the fall in real GDP. Liquidity ratio and nominal exchange rate affect the behaviour of real GDP in a mixed manner in both the phase of economic expansion and economic recession. These results show that economic policies should focus on household consumption and gross fixed capital formation to regulate the dynamics of the economy.

Under the Background of Internal Economic Cycle, Wuhan Cultural and Creative Industry Financial Support for Innovation Research

The rise of the tertiary industry has played a great role in the development of the Chinese economy. As the pillar industry, the cultural and creative industry can realize the upgrading and transformation through strengthening the support of new technologies and financial resources, thus bringing higher economic benefits. Focusing on the background of the internal economic circulation, this paper analyzes the financial support status and existing problems of the cultural and creative industry in Wuhan, puts forward the innovative ideas of the financial support of the Wuhan cultural and creative industry in the future, and provides reference for the rapid development of the Chinese cultural and creative industry in the future.

Editorial

We are truly excited to announce that the first issue in 2021 of Focus on ELT Journal brings together six contributions, five of which report valuable insights into the process of teaching and learning. In this issue, we also publish a book review, featuring one of the recently published books in the field.We are happy that our journal is steadily gaining recognition in the field of ELT since we have started receiving a higher number of submissions from different contexts, which simply makes our editorial tasks more challenging. Yet, not only does this help us understand the significance of our efforts in making our journal one of the resourceful and reliable venues for people of academic interest, but also it makes us much more motivated to pursue our goal to be recognized by the specialists in the field. To do this, we ensure that during the manuscript decision processes, we follow stringent publication ethics and rigorous external and internal reviewing cycles with the help of our editorial team and dedicated reviewers. Here, we cordially would like to express our gratitude to our esteemed editorial board members and eleven respected reviewers of this issue as featured above in ‘Reviewers of the current issue’ section.

ФОРМУЛИРОВКА МЕТОДА ОЦЕНКИ ВЕРОЯТНОСТИ БЕЗОТКАЗНОЙ РАБОТЫ КОНСТРУКЦИЙ НА ОСНОВЕ СОЧЕТАНИЯ СТАТИСТИЧЕСКОГО МОДЕЛИРОВАНИЯ И ЧИСЛЕННЫХ МЕТОДОВ ОЦЕНКИ НАПРЯЖЕНИЙ

In this paper, methods for estimating the reliability of constructions are considered. The formulation of a method for estimating the reliability of the design based on a combination of statistical modeling and numerical methods for evaluating stresses is given. The method is based on a "load – bearing capacity" model, which takes into account both stochasticity of mechanical properties of construction materials, randomness of geometric characteristics, and loads of a probabilistic nature. This new method is a system of n nested cycles. The number of governing parameters n depends on the design. The load variation series is calculated in the body of the internal cycle. The load is calculated numerically in terms of stresses using the finite element method. Any commercial solver such as Nastran, Ansys, or Abaqus can be used for this purpose. The probability of failure-free operation (reliability) is calculated involving the variational series of loads and load-carrying ability. For this purpose, the formalized estimation method based on empirical distributions is used. Fundamentals of the latter are available in the monograph "Reliability in Engineering Design" written by Kapur K.C. and Lamberson L.R.. A primary function of the proposed method is to evaluate the probability of failure-free operation of constructions under stationary or quasi-stationary random loads.

Contributions of external nutrient loading and internal cycling to cyanobacterial bloom dynamics in Lake Taihu, China: Implications for nutrient management

Contributions of external nutrient loading and internal cycling to cyanobacterial bloom dynamics in Lake Taihu, China: Implications for nutrient management

Вейвлет-анализ динамики волн заражения коронавирусом во Франции, Швеции и Китае.

In this work, the wavelet spectra were calculated and studied for time series representing the dynamics of the new cases of coronavirus infection in France, Sweden and China. It was found that the Wavelet spectra for these countries have characteristic different-scale internal cycles, the number of which depends on the nature of the quarantine activities. It was detected that structure of the Wavelet spectra, their duration is practically independent of the geographic location, density and population size.

氮磷肥对茶树锌硒等中微量元素吸收与分配的影响

锌（Zn）和硒（Se）及其他中微量元素（铝Al，钙Ca，铁Fe，铜Cu，锰Mn）是茶叶品质的重要指标，但茶树吸收Zn、Se能力及氮（N）磷（P）肥影响中微量元素吸收与分配的过程尚不清楚。以红壤丘陵区福鼎大白茶树为研究对象，开展Zn+Se、Zn+Se+N、Zn+Se+P、Zn+Se+N+P和对照共5种处理3次重复随机化区组试验，处理第3年春季分茶叶、成熟叶、吸收根、运输根和储藏根采集植物样品，测定其元素含量。结果表明，茶树地上和地下器官Zn和Se及其他中微量元素对N、P、Zn、Se添加的响应具分异性。与对照相比，茶树地上和地下器官Zn和Se含量均显著增加，与Zn+Se相比，施N和/或P肥仅显著提高茶叶和成熟叶Se含量（P<0.05）；与对照相比，施肥处理均显著提高吸收根和运输根Al、Fe含量以及储藏根Cu含量；运输根Mn含量表现为Zn+Se+N、Zn+Se+P、Zn+Se+N+P显著高于对照，储藏根Mn含量为Zn+Se+N+P显著高于其他处理；茶树各器官Ca含量对施肥处理无显著响应。此外，茶叶和成熟叶的Zn含量与吸收根显著正相关，而Se含量则与储藏根显著正相关。茶树具有吸收和积累Zn和Se的能力，而施N、P肥有助于提高茶叶Se含量，研究结果为红壤丘陵区培育高品质锌硒茶及营建生态高值茶园提供了依据。;Zinc (Zn), selenium (Se), and other trace elements, such as aluminum (Al), calcium (Ca), iron (Fe), copper (Cu), and manganese (Mn), are important indexes of tea quality. In Camellia sinensis the uptake mechanism of Zn and Se and the internal cycles of trace elements in response to nitrogen (N) and phosphorus (P) fertilizers are unclear. The tea plant Fudingdabai, located in the red-soil hilly region of China, was selected for a randomized block experiment with three replications of five treatments: Zn+Se, Zn+Se+N, Zn+Se+P, Zn+Se+N+P, and a control (CK). After three years of fertilization, trace element concentrations were measured in the tea and mature leaves and the absorptive, transportive, and storative roots. The concentrations of Zn, Se, and other trace elements in the above- and below-ground organs exhibited divergent responses to the treatments. In all of the organs, Zn and Se were significantly elevated in the fertilized plots. In the tea and mature leaves, Se concentrations significantly increased in the Zn+Se treated plots with N and/or P. Al and Fe (in the absorptive and transportive roots) and Cu (in the storative roots) were significantly elevated in the fertilized plots. Mn was more prevalent in the transportive roots of the Zn+Se+N, Zn+Se+P, and Zn+Se+N+P treated plots. In the storative roots, Mn increased only in the Zn+Se+N+P treatment. Ca did not differ. There was a positive correlation between Zn in the tea and mature leaves and Zn in the absorptive roots, while Se in the tea and mature leaves was positively correlated with Se in the storative roots. These results suggest that tea plants can absorb and accumulate Zn and Se, and N and P fertilizers increase Se levels in tea leaves. This study provides a basis for cultivating high-quality tea with abundant Zn and Se and for establishing tea gardens in the red-soil hilly region of China.

The influence of the hydrogen injection timing on the internal combustion engine working cycle

From an ecological aspect, the hydrogen has all properties to be a very good fuel for internal combustion engines. However the high combustion speed, as well as the possibility of backfire, is inconvenient properties of port injection. In this paper, the influence of the injection timing on the internal combustion engine working cycle parameters (pressure and temperature) was investigated deeply. The investigation, of the injection timing influence on the internal combustion engine working cycle parameters, was performed numerically by application of ANSYS software. It was observed the geometry of the real engine with added pre chamber, in order of layer mixture formation and pressure damping, because of high combustion speed. The results are presented for four cases with different injection timing and the same spark timing. By earlier injection, the time for mixing rise as well as the possibility of homogenization and uniform mixture creation, in pre chamber and cylinder. This claim it is confirmed on the basis of obtaining pressure and pressure rise gradient, which are growing with earlier injection, because of hydrogen combustion characteristics in stoichiometric mixture. The higher pressures as well as the surface under the diagram are positive from the aspect of the engine efficiency. However, with the earlier injection, the values of the pressure rise gradient are higher than for the classic Diesel engine. This means that this phenomena can cause brutal engine work from the aspect of mechanical stresses. However the value of the maximum pressure is smaller than this in a Diesel engine, this is due to added pre chamber, which has decreased the compression ratio.

Internal Tide Cycle and Topographic Scattering Over the North Mid‐Atlantic Ridge

AbstractInternal tides are a predominant source of high‐frequency variability and diapycnal mixing in the ocean. Understanding their dynamics and lifecycle is necessary to better understand their role in the ocean circulation. In this study, we describe and quantify internal tide generation, propagation, and dissipation in a sector of the North Mid‐Atlantic Ridge, using high‐resolution numerical simulations with realistic bathymetry and stratification. We show that the generation and dissipation of internal tides, as well as the distribution of internal tides among vertical modes, exhibit high spatial variability. We find that topographic scattering leads to a significant transfer of energy toward high vertical modes and thereby enhances internal tide dissipation. On average, and especially on the ridge, this mechanism is dominant over the conversion from the barotropic tide for transferring energy to high (7) vertical modes. The magnitude of the scattering of the first baroclinic internal mode is found to be in good agreement with theoretical predictions.