Mass Redistribution Research Articles

Interdecadal variations and causes of the relationship between the winter East Asian monsoon and interhemispheric atmospheric mass oscillation

The East Asian winter monsoon (EAWM) intensifies in the early twenty-first century and links with frequent impacts of large-scale persistent extreme cold events in winter in East Asia in recent years. We found that there has been a significant positive correlation between the EAWM and Interhemispheric Oscillation (IHO). However, conspicuous interdecadal variations have occurred in the relationship between the EAWM and IHO. The relationship between the IHO and EAWM was most significant during 1979–2020, but this relationship was weak and insignificant during 1962–1978. During 1979–2020, the atmospheric mass (surface pressure) difference between the Northern Hemisphere (NH) and Southern Hemisphere (SH) during 1979–2020 was significantly reduced by 7.85% (0.75 × 1015 kg) compared with that during 1962–1978. Such interhemispheric redistribution of atmospheric mass (AM) has had a distinct impact on the land-sea pressure contrast in East Asia and has intensified the connection between the EAWM and IHO. A strengthened EAWM has resulted in notable cooling and more severe winters in China. The apparent exportation of AM in the Antarctic region is an important driving factor for this interhemispheric change. The accompanying anomalous accumulation of AM in the NH is linked with an increase in the pressure difference between land and sea in East Asia, resulting in intensifying correlation between IHO and the EAWM. The decadal enhancement of the IHO during 1979–2020 was closely connected with conspicuous warming in the tropical troposphere/lower stratosphere (UTLS). A seesaw pattern of anomalous air temperature and ozone between tropical and Antarctic UTLS has induced a decrease in Antarctic ozone masses and air temperature and has strengthened the polar vortex, corresponding to a decadal enhancement of interhemispheric AM imbalance.

Designing Satellite Constellations to Observe Earth’s Time-Varying Gravity from Clock Frequency Comparisons

The nondominated sorting genetic algorithm III (NSGA-III) is used to design nonsymmetric satellite constellations to observe large-scale high-frequency gravity variations that would serve as complementary systems to other dedicated gravity field mapping missions such as the Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On missions. The functionality of the NSGA-III method is validated by reproducing optimal surface-coverage satellite constellations from the literature. Then, NSGA-III is used to generate nondominated constellations tuned to detect short-term long-wavelength gravity field variations. The constellations are used to generate subweekly gravity field solutions from clock frequency comparison measurements. The effectiveness of NSGA-III for optimizing nonsymmetric constellations was demonstrated because the constellations obtained from NSGA-III were consistently superior in performance than traditional symmetric constellations. Furthermore, the results showed that the time-varying signals of interest (that is, gravity coefficients through the spherical harmonic degree and order of seven at daily intervals) can be unambiguously resolved by assuming an optical clock with a fractional frequency uncertainty representative of current technology. The ability to monitor these short-term long-wavelength signals on a global scale would observe a spectrum of the gravity field inherently undetectable by GRACE-like missions, and it would provide new insight to the understanding of global mass redistribution processes.

Constraining the Venus Interior Structure with Future VERITAS Measurements of the Gravitational Atmospheric Loading

The complex dynamics of the Venus atmosphere produces a periodic mass redistribution pattern that creates a time-variable modulation of the gravity field of Venus. This gravity signal depends on the net transport of mass across the globe and on the response of the solid body to the normal loading of its crust imparted by the atmosphere. In this work, we explore the possibility of measuring this phenomenon with VERITAS, a NASA Discovery-class mission. By simulating the gravity science experiment, we explore the possibility of measuring the response of Venus to the atmospheric loading, parametrized by the loading Love numbers (), and assess the dependence of these parameters on fundamental interior structure properties. Using the most recent models of Venus’ interior, we compute the Venus Love numbers in a compressible viscoelastic setting and compare them with the predicted uncertainty of the VERITAS measurements. We show that VERITAS will measure at the 4% level and that this measurement could possibly help to distinguish between different equally plausible interior structure models, especially allowing us to distinguish different rheological laws. We also show that a measurement campaign such as the VERITAS gravity science investigation has the potential of measuring not only at the loading forcing frequency, but also at the tidal frequency, ultimately providing a way to probe the response of the planet at different forcing periods.

Sea-level trend variability in the Mediterranean during the 1993–2019 period

Sea-level change is one of the most concerning climate change and global warming consequences, especially impacting coastal societies and environments. The spatial and temporal variability of sea level is neither linear nor globally uniform, especially in semi-enclosed basins such as the Mediterranean Sea, which is considered a hot spot regarding expected impacts related to climate change. This study investigates sea-level trends and their variability over the Mediterranean Sea from 1993 to 2019. We use gridded sea-level anomaly products from satellite altimetry for the total observed sea level, whereas ocean temperature and salinity profiles from reanalysis were used to compute the thermosteric and halosteric effects, respectively, and the steric component of the sea level. We perform a statistical change point detection to assess the spatial and temporal significance of each trend change. The linear trend provides a clear indication of the non-steric effects as the dominant drivers over the entire period at the Mediterranean Sea scale, except for the Levantine and Aegean sub-basins, where the steric component explains the majority of the sea-level trend. The main changes in sea-level trends are detected around 1997, 2006, 2010, and 2016, associated with Northern Ionian Gyre reversal episodes, which changed the thermohaline properties and water mass redistribution over the sub-basins.

The influence of duct wall shape on mass redistribution in supercritical water-cooled reactor fuel assembly

Based on the fuel assembly of supercritical water-cooled reactor, a 19-rod bundle with triangular arrangement is established and different shapes of duct wall are used to adjust the hydraulic diameter of the external sub-channel. The Reynolds stress model (RSM) and enhanced wall treatment were employed to simulate the fluid flow and heat transfer phenomena of supercritical water and the mass redistribution in fuel assembly. The result shows that the hydraulic diameter difference between internal and external sub-channels and the physical properties of supercritical water are the main factors affecting the mass redistribution phenomenon. The mass redistribution can be effectively controlled by adjusting the hydraulic diameter of the external sub-channel. As the hydraulic diameter of the external sub-channel decreases, the fluid accumulation to the external sub-channel gradually weakens and then reverses to the internal sub-channel accumulation. Meantime, comparing with the primary model, the overall heat transfer effect of internal and external sub-channel can be balanced and kept at a high level by weakening the mass redistribution. Besides, the circumferential non-uniformity of the outermost fuel rod is affected by the local hydraulic diameter and the mass redistribution. Mass redistribution is the dominant factor and the local hydraulic diameter can only start to affect the circumferential wall temperature until the mass redistribution is weakened to a certain extent.

Vibration analysis on newly designed painting supports for the Cranach exhibition 2022 at Herzogin Anna Amalia Bibliothek

AbstractThe effect of vibration on the condition of sensitive works of art continues to be of great importance to museums. Vibrations contribute to irreversible changes in the complex materiality of art and cultural heritage. In cooperation with the Klassik Stiftung Weimar, the Institute of Engineering and Computational Mechanics at the University of Stuttgart accompanied an exhibition setup. The museum and partners designed free‐standing columns in the exhibition hall to support valuable works of art. Due to their original design, these are susceptible to vibrations. Thus, the question arises as to what extent these columns should be modified in order to reduce these vibrations. In this study, measurements were taken on the floor and on the columns using a variety of measuring techniques. It was investigated which excitations from the environment propagate to the artwork. It was confirmed that vibrations from the environment, such as road traffic and museum visitors in the exhibition room, are sources of excitation.Experimental modal analysis was used to identify the characteristic vibration behaviour of these columns. By using finite element methods, a simulation model was set up allowing to investigate modifications to the columns in order to predict the change in vibration behaviour. Based on the simulation modifications, structural changes were made to the system through stiffening of individual components and redistribution of masses.

Key Role of Subdaily Wind Variability for Tropical Surface Wind Stress

Abstract High-frequency observations of surface winds over the open ocean are available only at limited locations. However, these observations are essential for assessing atmospheric influences on the ocean, validating reanalysis products, and building parameterization schemes. By analyzing high-frequency measurements from the Global Tropical Moored Buoy Array, the effects of subdaily winds on the mean surface wind stress magnitude are systematically examined. Subdaily winds account for 12.4% of the total stress magnitude on average. The contribution is enhanced over the intertropical convergence zone and reaches a maximum (28.5%) in the equatorial western Pacific. The magnitude of the contribution is primarily determined by the kinetic energy of subdaily winds. Compared to the buoy observations, the ERA5 and MERRA2 subdaily winds underestimate this contribution by 51% and 63% due to underestimations of subdaily kinetic energy, leading to 7% and 8% underestimations in the total stress magnitude, respectively. Two new gustiness parameterization schemes related to precipitation are developed to account for the effect of subdaily winds, explaining ∼80% of the contribution from subdaily winds. Considering the importance of wind stress for ocean–atmosphere interactions, the inclusion of these parameterization schemes in climate models is expected to substantially improve simulations of large-scale climate variability. Significance Statement Surface wind stress drives upper-ocean circulation, which is critical for the redistribution of mass, momentum, and energy in the ocean. Moreover, it is one of the key factors controlling oceanic turbulent mixing and therefore has significant impacts on the distribution of temperature, salinity, and associated ocean variability. Using high-resolution buoy observations, this study highlights the importance of subdaily winds for integrated wind stress estimates. In addition, it finds that current state-of-the-art and widely used reanalysis products largely underestimate the effect of subdaily winds. Two new parameterization schemes are developed, leading to a better representation of the effect of subdaily winds. Including the proposed parameterization schemes in climate models is expected to substantially improve their simulations of large-scale climate variability.

The prospects of integrated use of high-precision geometric and GNSS leveling for studying neotectonic processes at geodynamic polygons

This article presents the development of a methodology for determining the deviation of straight lines using high-precision leveling and GNSS measurements, its estimated accuracy, and the justification of technological parameters for constructing geodynamic testing grounds. This problem is essential in the geodetic and geophysical fields since changes in the shape of the equipotential surface may indicate a redistribution of mass in the Earth's crust and other natural phenomena. Studying this problem using the proposed methodology can provide insight into the main geological processes, gravitational potentials, and neotectonic processes. Monitoring of changes and deformation of the Earth's surface is of great importance for understanding solid processes on the Earth, especially those caused or intensified by anthropogenic activities, which currently pose global challenges to humanity. The study presents the analysis of the existing methods for determining the change in the shape of the equipotential surface. It substantiates the advantages of using high-precision leveling and GNSS measurements to ensure the accuracy and reliability of the results. The calculation formulas for estimating the accuracy of determining the deviation of straight lines with the possibility of studying the shape of equipotential surfaces with millimeter accuracy are proposed. The methodology and technological parameters have been developed, which can be used to determine the change in the deviation of a straight line on geodynamic polygons with an accuracy of 0.1-0.2". Also, the possibility of using the research results to determine changes in the shape of equipotential surfaces is theoretically substantiated. Namely, changes in their radii of curvature are associated with the possibility of predicting neotectonic processes according to modern scientific hypotheses. Keywords: deviation of straight lines; global navigation satellite systems; geometric leveling; orthometric excesses; geoid, geodetic heights.

Novel atomizer concept for CCS applications: Impinging effervescent atomizer

The concept design, testing of spray characteristics, and performance comparison of an original type of atomizer, the impinging effervescent atomizer (IEA), are introduced in this study. The liquid impinging is beneficially deployed in plain-orifice and external mixing twin fluid atomizers. IEA uses a collision of two or more effervescent liquid streams to improve the atomization and alter the spray characteristics. The Phase Doppler Anemometry (PDA) measurement technique and high-speed visualization of the liquid discharge and spray structure were used. The discharge coefficient (Cd), atomization efficiency (ηa), spray characteristics as a spray cone angle (SCA), integral Sauter mean diameter (ISMD), integral relative span factor (IRSF), and droplet size and velocity distribution inside the spray were investigated. The correlations for Cd, SCA, ISMD and IRSF are provided for a fast and reliable atomizer design to fit any application and operating conditions. The IEA provides a controllable SCA governed mainly by the exit orifice geometry. The ISMD is primarily controlled by the gas to liquid ratio (GLR) and the inlet pressure (pin). The impinging angle (β) has little effect on ISMD. A narrower droplet size distribution, mass redistribution within the spray, and a more uniform droplet size spatial distribution were observed for the IEA in comparison to other tested atomizers. The IEA spray covers 116% more area than single-orifice effervescent sprays, and the area coverage can be controlled by β. This coverage increases by 177% if β changes from 15 to 45°. Spray eccentricity (e) decreases with the increase of the number of the exit orifices (No) resulting in a more uniform droplet spatial distribution. The β, GLR and pin have no effect on e. The ηa of the IEA is equivalent to other internally mixing twin-fluid atomizers; the atomization air contains more than 90% of the delivered energy. The favourable IEA spray characteristics, such as IRSF, ISMD, spray coverage, SCA and ηa, enable the potential use of IEA in mass-transfer related processes and especially in CO2 capture columns.

Body composition in patients with heart failure

The redistribution of body composition components in heart failure (CHF) is an urgent and poorly understood issue. Despite the significant impact of a decrease in muscle mass, redistribution of fat mass on the course and prognosis of HF, body composition is rarely taken into account in the treatment of this disease. In this regard, the purpose of this review was to systematize the available data and draw the attention of clinicians to this problem. The data presented in the review make it possible to consider the components of body composition as controllable factors, the normalization of which improves the prognosis in patients with HF. The study of pathophysiological mechanisms for the development of body composition anomalies in HF will make it possible to search for new therapeutic targets. Assessment of body composition will make it possible to develop an individual strategy for the treatment of HF, including a set of non-drug measures.

Regionalizing the sea-level budget with machine learning techniques

Abstract. Attribution of sea-level change to its different drivers is typically done using a sea-level budget approach. While the global mean sea-level budget is considered closed, closing the budget on a finer spatial scale is more complicated due to, for instance, limitations in our observational system and the spatial processes contributing to regional sea-level change. Consequently, the regional budget has been mainly analysed on a basin-wide scale. Here we investigate the sea-level budget at sub-basin scales, using two machine learning techniques to extract domains of coherent sea-level variability: a neural network approach (self-organizing map, SOM) and a network detection approach (δ-MAPS). The extracted domains provide more spatial detail within the ocean basins and indicate how sea-level variability is connected among different regions. Using these domains we can close, within 1σ uncertainty, the sub-basin regional sea-level budget from 1993–2016 in 100 % and 76 % of the SOM and δ-MAPS regions, respectively. Steric variations dominate the temporal sea-level variability and determine a significant part of the total regional change. Sea-level change due to mass exchange between ocean and land has a relatively homogeneous contribution to all regions. In highly dynamic regions (e.g. the Gulf Stream region) the dynamic mass redistribution is significant. Regions where the budget cannot be closed highlight processes that are affecting sea level but are not well captured by the observations, such as the influence of western boundary currents. The use of the budget approach in combination with machine learning techniques leads to new insights into regional sea-level variability and its drivers.

High resolution modeling of aluminium transport in a fjord estuary with focus on mean circulation and irregular flow events

Environmental impact assessments of trace metals and radionuclides in estuarine waters will benefit from numerical transport models that can provide detailed and accurate predictions of concentrations of harmful physico-chemical forms of contaminants at adequate spatial and temporal resolution. Aiming to study the potential of aluminium (Al) exposure to biota, a transport model (OpenDrift) including dynamic speciation and transformation processes was improved and applied, using three-dimensional hydrodynamic flow fields from a numerical ocean model (ROMS) at high horizontal resolution (32 m). Al transport and concentration was computed along the Sandnesfjorden Fjord, south-eastern Norway, from river outlet to open coastal waters. Validation of the circulation model with 29 hydrographic profiles from Sandnesfjorden showed substantial improvements compared to previous studies due to optimized model configuration (salinity overestimation decreased from >7 psu to <4 psu). Modeled Al data compared well with observed surface Al concentration from 12 locations and the along-fjord decreasing trend in Al-concentration was well reproduced (error ratios were <2 in Sandnesfjorden). Except in the channel area, both salinity and Al concentration estimates lie well within the expected variability. However, the transport modeling gave a more detailed site-specific picture of the Al concentration, suggesting more scattered and variable fields than indicated by observational data (variations of a factor 3–4 over short spatiotemporal scales). Reversed flow events (surface flow into the fjord) caused considerable mixing and redistribution of water masses, affecting both horizontal mixing of river discharges with coastal water as well as vertically as surface water mixed with deeper water masses. These blocking events strongly changed properties and distribution of the water masses giving rise to local and short-term high Al-exposure episodes (variations of a factor of 10 over a 12 h period) in the fjord that may pose risks to biota and therefore should be taken into account in impact and risk assessments.

Sea level response to late Pliocene-Quaternary erosion and deposition in Scandinavia

Erosion and deposition can perturb regional sea level significantly by altering the Earth's surface and by redistributing mass. However, no studies have investigated the importance of these geomorphic processes for glacial settings on glacial-interglacial time scales, despite large erosion rates and the inherent importance of sea-level changes for ice-sheet dynamics and stability. Here we quantify how glacial erosion and depositional processes have affected relative sea level in western Scandinavia where glacial activity has reoccured periodically throughout the late Pliocene-Quaternary. By comparing offshore sediment volumes with onshore topographic relief, we quantify erosion and deposition for the last two glacial cycles as well as the entire late Pliocene-Quaternary. Specifically, we develop a history of erosion and deposition for the last two glacial cycles by scaling the erosion rate with the normalised global ice volume through time. We use the ice model ICE6G_C as a global ice history and calculate sea-level changes through time as a result of ice, water, and sediment loading using a global gravitationally self-consistent sea-level model. Our results show that geomorphic mass redistribution, excluding direct changes in ocean depth owing to erosion and deposition, has caused a sea-level fall of ≈50–100 m along the southern coast of Norway during the last two glacial cycles reaching ≈120 m in the offshore Skagerak region. During the late Pliocene-Quaternary, the total sea-level fall reach as much as ≈ 310 m in Skagerak. These results showcase the importance of erosion and deposition for the relative sea-level history of Scandinavia with implications for studies of ice-sheet history and regional glacial rebound in this region and elsewhere.

Mass transfer and element redistribution during chloritization of metamorphic biotite in a metapelite: insights from compositional mapping

Abstract Fluid-driven reactions are common in the upper crust, leading to mineral replacement and element redistribution on a kilometer to a micron scale. One common fluid-induced reaction is the chloritization of biotite. Chloritization can lead to the production of multiple phases, such as K-feldspar, titanite, and rutile, depending on local chemistry and fluid composition. Here, we compare different approaches to mass balance calculations using an altered garnet-bearing metapelite collected from Ny Friesland, Svalbard Archipelago, Norway. In the outcrop, amphibolite facies schists are cut by joints that acted as fluid pathways that led to the development of a narrow (~5 cm) alteration zone. Alteration involved the replacement of biotite by chlorite + K-feldspar ± rutile ± titanite. Mass balance calculations based on whole-rock composition and assuming immobile Zr indicate the addition of H2O, Si, Ti, Fe, or Mg and the removal of K or Ca. In contrast, mass balance calculated for the pseudomorphic replacement of Bt by Chl + Kfs ± Rt ± Ttn using X-Ray maps for three focused areas indicates the removal of Si or Ti rather than addition. Moles of product phase and elements gained or lost during this reaction varies between individual areas. This variation suggests that fluid heterogeneity and local chemistry governed the progression of the replacement reaction. All the product phases involved in the biotite breakdown are geochronometers and/or geothermometers, providing new opportunities for the petrochronology of fluid-induced reactions.

Vertical redistribution of principle water masses on the Northeast Greenland Shelf

The Northeast Greenland shelf (NEGS) is a recipient of Polar Water (PW) from the Arctic Ocean, Greenland Ice Sheet melt, and Atlantic Water (AW). Here, we compile hydrographical measurements to quantify long-term changes in fjords and coastal waters. We find a profound change in the vertical distribution of water masses, with AW shoaling >60 m and PW thinning >50 m since early 2000's. The properties of these waters have also changed. AWis now 1 °C warmer and the salinity ofsurface waters and PW are1.8 and 0.68 lower, respectively. The AW changes have substantially weakened stratification south of ~74°N, indicating increased accessibility of heat and potentially nutrients associated with AW. The Atlantification earlier reported for the eastern Fram Strait and Barents Sea region has also propagated to the NEGS. The increased presence of AW, is an important driver for regional change leading to a likely shift in ecosystem structure and function.

Gravity yearly transient change around the epicenter of 2022 MS 6.9 Menyuan earthquake, China and seismotectonic implications

The MS 6.9 Menyuan earthquake occurred in the northeastern Tibetan Plateau on 8 January 2022. High-precision absolute gravity observations provide a unique perspective on seismotectonic feature of strong continental earthquakes. An obvious and coincident gravity increase about 5 years before the Menyuan earthquake with the rate up to 3.94 μGal/yr is observed at four absolute gravity stations within 350 km away from the epicenter. These four stations have been carried out repeat gravity observations by the Crustal Movement Observation Network of China (CMONOC) for more than a decade. The observed gravity changes could not be reasonably explained by the land water storage change nor crustal vertical deformation and thus might be related to the processes in the crust. A disc-shaped equivalent source region with a radius of 175 km is then modeled, based on the residual gravity rates. We find that the seismicity increases gradually in the modeled source region from about 2017 to 2021, similar to the pattern of absolute gravity change. Furthermore, the spatiotemporal distribution of epicenters is consistent with the fluids diffusion model, indicating that this could be related to the redistribution of deep fluid mass. With consideration of the near-surface processes, regional crustal structure, and seismicity, multiple lines of evidence consistently refer to the presence of deep fluids migration before the Menyuan earthquake. Our results suggest that high-precision absolute gravimetry can be used to monitor crustal fluid environment and determine mass changes in the source regions of potential large earthquakes.

ESMGFZ Products for Earth Rotation Prediction

Abstract The Earth System Modelling Group of GeoForschungsZentrum Potsdam (ESMGFZ) provides geodetic products for gravity variations, Earth rotation excitations, and Earth surface deformations related to mass redistributions and mass loads in the atmosphere, ocean, and terrestrial water storage. Earth rotation excitation compiled as effective angular momentum (EAM) functions for each Earth subsystem (atmosphere, ocean, continental hydrology) are important for Earth rotation prediction. Especially the 6-day forecasts extending the model analysis runs offer essential information for the improvement of ultra-short-term Earth rotation predictions. In addition to the individual effective angular momentum function of each subsystem, ESMGFZ calculates a combined EAM prediction product. Adjusted to the official Earth orientation parameter (EOP) products IERS 14C04 and Bulletin A, this EAM prediction product allows to extrapolate the polar motion and Length-of-Day parameter time series for 90 days into the future via the Liouville equation. ESMGFZ submits such an EOP prediction to the 2nd EOPPCC campaign.

Examination of the Effects of Circular Ring on the Developing Region of Axisymmetric Round Jet Flow

The influence of circular ring on the dynamics of the flow on the developing region of axisymmetric round jet is examined. The jet is produced from a smoothly contracting round nozzle and the flow structure is controlled by varying the air blower speed in order to obtain various Reynolds numbers. Ring made of 0.5 mm diameter and positioned at x/d=0.12 is used to perturb the shear layer of round nozzle of diameter 25.4 mm. Hot wire measurement is carried out at the near and intermediate fields (0.5≤x/d≤30) for both perturbed (disturbed) and unperturbed (undisturbed) jet. Measurements were also made in the confined flow for both cases. The results show increase in potential core and further reduction in centerline velocity at the end of potential core for disturbed jet when compared with undisturbed jet for the Reynolds numbers considered (5210, 7000 and 9117). Spread rate reduces in perturbed jet due to the shear layer compression in the developing region. However, velocity profile seems not to be affected by the perturbation in the near field but a compression of the profile is noticed further away from near field. Also, the flow measured in the pipe attached to the nozzle for both cases show almost constant value of normalized centerline velocity and has reduced values when compared with undisturbed jet. The foregoing clearly indicates mass redistribution in the confined region. Overall, while the wavelength of the oscillation is unchanged, the magnitude is altered suggesting a change in the dynamics of the layer.

On Theoretical Foundations of Aerolimnology: Study of Fresh Water Bodies and Coastal Territories Using Air Robot Equipment

The integration of the methodological basis of several different sciences in interdisciplinary research is a characteristic feature of new mechanisms for solving modern applied problems. The emerging theoretical foundations of aerolimnology, as a new scientific direction, are considered from the point of view of the contribution of three key sciences to it: limnology, informatics and robotics. Classifications of methods and approaches of limnological research, airborne robotic means, and information technologies that are promising for solving problems in the field of aerolimnology are given. The task of the scientific direction of aerolimnology is formulated as the study of the possibilities and limitations of combined methods of remote sensory measurement, robotic sampling and analytical study of the parameters of freshwater ecosystems to monitor and predict the dynamics of their development. Among the main areas of aerolimnological research, the following are distinguished: the construction of orthophotomaps and photogrammetric spatial models of the bottom topography and individual elements of the bottom landscape and coastal zone of various scales; geological and geophysical mapping of the underwater part of the coastal zone; the study of phytoplankton, in particular, the "bloom" of water caused by cyanobacteria; study of distribution and migration of large representatives of hydrofauna; study of temperature fields and processes of redistribution of water masses. The limitations imposed on the use of unmanned aerial vehicles (UAVs) in sampling and monitoring coastal water areas are discussed, primarily weather-climatic, temporal, spatial, and technical. The advantage of using unmanned aerial vehicles in aerolimnology is justified by an increase in the speed of data acquisition, the possibility of approaching hard-to-reach and territorially remote objects, and a decrease in the influence of the human factor. The scientific novelty of the presented research consists in an attempt to integrate interdisciplinary knowledge when using unmanned aerial vehicles and processing the obtained data based on artificial intelligence technologies in the study of limnological objects and processes. The important role of geoinformation systems is noted and examples of maps of shore typification and geomorphology of Lake Ladoga are given, posted on the website of the Center for the Collective Use of Scientific Equipment "North-Western Center for Monitoring and Forecasting the Development of Territories" of the St. Petersburg Federal Research Center of the Russian Academy of Sciences. The main stages of the methodology for conducting aerolimnological studies using interdisciplinary approaches based on limnology, informatics and robotic tools operating in different environments are considered.

Spatial variability in winter mass balance on Storglaciären modelled with a terrain-based approach

AbstractAlthough most processes governing the surface mass balance on mountain glaciers are well understood, the causes and extent of spatial variability in accumulation remain poorly constrained. In the present study, we couple an energy balance–snow and firn mass-balance model to terrain-based modelling routines estimating mass redistribution by snowdrift, preferential deposition and avalanching. We find this newly coupled model improves the spatial accuracy of winter balance simulations on Storglaciären, Sweden, while retaining versatility and a low computational cost. Accumulation on Storglaciären is primarily driven by direct precipitation, which is locally increased due to small-scale orographic effects. Wind-driven snow transport leads to substantial deposition in the accumulation zone and slight erosion in the ablation zone. Avalanching is the smallest contributor to winter balance, but cannot be neglected. The role of mass transporting processes in maintaining the current mass equilibrium on Storglaciären highlights the necessity to understand the links between climatic predictors and accumulation in order to accurately assess climate sensitivity.