Location via proxy:   [ UP ]  
[Report a bug]   [Manage cookies]                
 
 
Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

Article Types

Countries / Regions

Search Results (39)

Search Parameters:
Keywords = Terra-i

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
23 pages, 10461 KiB  
Article
Effects of Anthropic Structures on Morphodynamic Beach Evolution along the Gulf of Roses (Northwestern Mediterranean, Spain)
by Antoni Calafat, Manel Salvador, Marta Guinau and José L. Casamor
Geosciences 2024, 14(10), 265; https://doi.org/10.3390/geosciences14100265 - 10 Oct 2024
Viewed by 515
Abstract
This study conducts a morphodynamic analysis of beaches located in the northern sector of the Gulf of Roses (NW Mediterranean, Spain). The primary objective is to investigate mid-short (2004–2020) term spatial and temporal variations in shoreline position and sedimentological behaviour. The study area [...] Read more.
This study conducts a morphodynamic analysis of beaches located in the northern sector of the Gulf of Roses (NW Mediterranean, Spain). The primary objective is to investigate mid-short (2004–2020) term spatial and temporal variations in shoreline position and sedimentological behaviour. The study area covers the northern part of the gulf, spanning 9.86 km, and includes both natural beaches and heavily anthropized ones. The following GIS methodologies were employed to study the variations in the coastline: QGIS for areas and DSAS-ArcGIS for transects, quantifying coastal changes from 2004 to 2020. Sediment samples were collected from both the dry beach and swash areas for each profile. The results reveal minor discrepancies in shoreline evolution data, depending on the method used (transects or areas). Profile-based analysis shows an average annual rate of −0.11 m·y−1 (ranging between 0.53 and −0.55 m·y−1), while areal-based results (2004–2020) indicate a total loss of −20,810 m2 (−1300 m2·y−1). Sediment grain size decreases northward (from 745 to 264 µm in the swash zone). Changes in shoreline position and grain size illustrate the impact of various anthropogenic structures on morphodynamic behaviour. These structures preferentially deposit specific grain sizes and impede sediment transport, which will cause an advance in the position of the shoreline and sediment grain sizes upstream and a reverse process downstream. This study underscores the influence of coastal anthropization on beach morphology and sedimentology, generating distinct morphodynamic behaviour. Full article
(This article belongs to the Section Sedimentology, Stratigraphy and Palaeontology)
Show Figures

Figure 1

24 pages, 11277 KiB  
Article
Trawling-Induced Sedimentary Dynamics in Submarine Canyons of the Gulf of Palermo (SW Mediterranean Sea)
by Marta Arjona-Camas, Claudio Lo Iacono, Pere Puig, Tommaso Russo and Albert Palanques
J. Mar. Sci. Eng. 2024, 12(7), 1050; https://doi.org/10.3390/jmse12071050 - 22 Jun 2024
Viewed by 917
Abstract
Bottom trawling in submarine canyons can affect their sedimentary dynamics, but studies addressing this topic are still scarce. In the Gulf of Palermo (NW Sicily, SW Mediterranean Sea), bottom trawling occurs on the continental slope, but principally concentrates within Oreto Canyon. Hydrographic profiles [...] Read more.
Bottom trawling in submarine canyons can affect their sedimentary dynamics, but studies addressing this topic are still scarce. In the Gulf of Palermo (NW Sicily, SW Mediterranean Sea), bottom trawling occurs on the continental slope, but principally concentrates within Oreto Canyon. Hydrographic profiles and time series data of temperature, turbidity, and currents obtained by a CTD probe and by moored instruments, respectively, revealed increased turbidity values and the presence of bottom and intermediate nepheloid layers coinciding with periods of bottom trawling activity. The delay between the onset of trawling activities along the Oreto canyon axis and the increase in water turbidity at the mooring location indicate that trawling resuspended particles are progressively advected down-canyon by hydrodynamic processes. Topographic waves and near-inertial currents seem to contribute to the sediment transport of resuspended particles as bottom and intermediate nepheloid layers. Results presented in this paper highlight the complex relationship between hydrodynamic processes and sediment resuspension by trawling in submarine canyons. Full article
Show Figures

Figure 1

19 pages, 3227 KiB  
Article
Hyperspectral Leaf Area Index and Chlorophyll Retrieval over Forest and Row-Structured Vineyard Canopies
by Luke A. Brown, Harry Morris, Andrew MacLachlan, Francesco D’Adamo, Jennifer Adams, Ernesto Lopez-Baeza, Erika Albero, Beatriz Martínez, Sergio Sánchez-Ruiz, Manuel Campos-Taberner, Antonio Lidón, Cristina Lull, Inmaculada Bautista, Daniel Clewley, Gary Llewellyn, Qiaoyun Xie, Fernando Camacho, Julio Pastor-Guzman, Rosalinda Morrone, Morven Sinclair, Owen Williams, Merryn Hunt, Andreas Hueni, Valentina Boccia, Steffen Dransfeld and Jadunandan Dashadd Show full author list remove Hide full author list
Remote Sens. 2024, 16(12), 2066; https://doi.org/10.3390/rs16122066 - 7 Jun 2024
Viewed by 1700
Abstract
As an unprecedented stream of decametric hyperspectral observations becomes available from recent and upcoming spaceborne missions, effective algorithms are required to retrieve vegetation biophysical and biochemical variables such as leaf area index (LAI) and canopy chlorophyll content (CCC). In the context of missions [...] Read more.
As an unprecedented stream of decametric hyperspectral observations becomes available from recent and upcoming spaceborne missions, effective algorithms are required to retrieve vegetation biophysical and biochemical variables such as leaf area index (LAI) and canopy chlorophyll content (CCC). In the context of missions such as the Environmental Mapping and Analysis Program (EnMAP), Precursore Iperspettrale della Missione Applicativa (PRISMA), Copernicus Hyperspectral Imaging Mission for the Environment (CHIME), and Surface Biology Geology (SBG), several retrieval algorithms have been developed based upon the turbid medium Scattering by Arbitrarily Inclined Leaves (SAIL) radiative transfer model. Whilst well suited to cereal crops, SAIL is known to perform comparatively poorly over more heterogeneous canopies (including forests and row-structured crops). In this paper, we investigate the application of hybrid radiative transfer models, including a modified version of SAIL (rowSAIL) and the Invertible Forest Reflectance Model (INFORM), to such canopies. Unlike SAIL, which assumes a horizontally homogeneous canopy, such models partition the canopy into geometric objects, which are themselves treated as turbid media. By enabling crown transmittance, foliage clumping, and shadowing to be represented, they provide a more realistic representation of heterogeneous vegetation. Using airborne hyperspectral data to simulate EnMAP observations over vineyard and deciduous broadleaf forest sites, we demonstrate that SAIL-based algorithms provide moderate retrieval accuracy for LAI (RMSD = 0.92–2.15, NRMSD = 40–67%, bias = −0.64–0.96) and CCC (RMSD = 0.27–1.27 g m−2, NRMSD = 64–84%, bias = −0.17–0.89 g m−2). The use of hybrid radiative transfer models (rowSAIL and INFORM) reduces bias in LAI (RMSD = 0.88–1.64, NRMSD = 27–64%, bias = −0.78–−0.13) and CCC (RMSD = 0.30–0.87 g m−2, NRMSD = 52–73%, bias = 0.03–0.42 g m−2) retrievals. Based on our results, at the canopy level, we recommend that hybrid radiative transfer models such as rowSAIL and INFORM are further adopted for hyperspectral biophysical and biochemical variable retrieval over heterogeneous vegetation. Full article
(This article belongs to the Section Environmental Remote Sensing)
Show Figures

Graphical abstract

55 pages, 29220 KiB  
Article
Vision System for the Mars Sample Return Capture Containment and Return System (CCRS)
by Brent J. Bos, David L. Donovan, John I. Capone, Chen Wang, Terra C. Hardwick, Dylan E. Bell, Yuqing Zhu, Robert Podgurski, Bashar Rizk, Ireneusz Orlowski, Rachel A. Edison, David A. Harvey, Brianna Dizon, Lindsay Haseltine, Kristoffer C. Olsen, Chad Sheng, Robert R. Bousquet, Luan Q. Vo, Georgi T. Georgiev, Kristen A. Washington, Michael J. Singer, Stefan Ioana, Anloc H. Le, Elena M. Georgieva, Michael T. Hackett, Michael A. Ravine, Michael Caplinger, Phillip Coulter, Erin Percy, Charles Torisky, Jean-Marie Lauenstein, Kaitlyn L. Ryder, Michael J. Campola, Dillon E. Johnstone, William J. Thomes, Richard G. Schnurr, John C. McCloskey, Eugenia L. De Marco, Ellen Lee, Calinda M. Yew, Bo Yang, Mingyu Han and Bartosz Blonskiadd Show full author list remove Hide full author list
Aerospace 2024, 11(6), 456; https://doi.org/10.3390/aerospace11060456 - 5 Jun 2024
Viewed by 1173
Abstract
The successful 2020 launch and 2021 landing of the National Aeronautics and Space Administration’s (NASA) Perseverance Mars rover initiated the first phase of the NASA and European Space Agency (ESA) Mars Sample Return (MSR) campaign. The goal of the MSR campaign is to [...] Read more.
The successful 2020 launch and 2021 landing of the National Aeronautics and Space Administration’s (NASA) Perseverance Mars rover initiated the first phase of the NASA and European Space Agency (ESA) Mars Sample Return (MSR) campaign. The goal of the MSR campaign is to collect scientifically interesting samples from the Martian surface and return them to Earth for further study in terrestrial laboratories. The MSR campaign consists of three major spacecraft components to accomplish this objective: the Perseverance Mars rover, the Sample Retrieval Lander (SRL) and the Earth Return Orbiter (ERO). Onboard the ERO spacecraft is the Capture, Containment and Return System (CCRS). CCRS will capture, process and return to Earth the samples that have been collected after they are launched into Mars orbit by the Mars Ascent Vehicle (MAV), which is delivered to Mars onboard the SRL. To facilitate the processing of the orbiting sample (OS) via the CCRS, we have designed and developed a vision system to determine the OS capture orientation. The vision system is composed of two cameras sensitive to the visible portion of the electromagnetic spectrum and two illumination modules constructed from broadband light emitting diodes (LED). Vision system laboratory tests and physics-based optical simulations predict CCRS ground processing will be able to correctly identify the OS post-capture orientation using only a single vision system image that is transmitted to Earth from Mars orbit. Full article
(This article belongs to the Special Issue Spacecraft Sample Collection)
Show Figures

Figure 1

23 pages, 21239 KiB  
Article
Geochemistry and Mineralogy of the Clay-Type Ni-Laterite Deposit of San Felipe (Camagüey, Cuba)
by Esperança Tauler, Salvador Galí, Cristina Villanova-de-Benavent, Alfonso Chang-Rodríguez, Kenya Núñez-Cambra, Giorgi Khazaradze and Joaquín Antonio Proenza
Minerals 2023, 13(10), 1281; https://doi.org/10.3390/min13101281 - 29 Sep 2023
Cited by 1 | Viewed by 1364
Abstract
The Ni-laterite deposit at the San Felipe plateau, located 30 km northwest of Camagüey, in central Cuba, is the best example of a clay-type deposit in the Caribbean region. San Felipe resulted from the weathering of mantle peridotites of the Cretaceous Camagüey ophiolites. [...] Read more.
The Ni-laterite deposit at the San Felipe plateau, located 30 km northwest of Camagüey, in central Cuba, is the best example of a clay-type deposit in the Caribbean region. San Felipe resulted from the weathering of mantle peridotites of the Cretaceous Camagüey ophiolites. In this study, a geochemical and mineralogical characterization of two profiles (83 and 84) from the San Felipe deposit has been performed by XRF, ICP-MS, quantitative XRPD, oriented aggregate mount XRD, SEM, FE-SEM, and EMPA. Core 83, with a length of 23 m and drilled in the central part of the plateau, presents a notable concentration of cryptocrystalline quartz fragments and a rather poor content of NiO, averaging 0.87 wt.%. Core 84, which is 12 m long and drilled at the border of the plateau, lacks silica fragments and presents a higher NiO content, averaging 1.79 wt.%. The smectite structural formulae reveal that they evolve from trioctahedral to dioctahedral towards the top of the laterite profiles. Quantitative XRD analyses indicate that smectite is a dominant Ni-bearing phase, accompanied by serpentine and minor chlorite. Serpentine, as smectite, is enriched in the less soluble elements Fe3+, Al, and Ni towards the top of the profiles. Core 83 seems to have been affected by collapses and replenishments, whereas core 84 may have remained undisturbed. Full article
(This article belongs to the Special Issue Geochemistry and Mineralogy of Ni-Co Laterite Deposits)
Show Figures

Figure 1

26 pages, 11251 KiB  
Article
Effects of Road Dust Particle Size on Mineralogy, Chemical Bulk Content, Pollution and Health Risk Analyses
by Dídac Navarro-Ciurana, Mercè Corbella and Daniel Meroño
Int. J. Environ. Res. Public Health 2023, 20(17), 6655; https://doi.org/10.3390/ijerph20176655 - 26 Aug 2023
Cited by 2 | Viewed by 2133
Abstract
Because of the rising environmental and health concerns associated with atmospheric pollution caused by potentially toxic elements (PTEs), several road dust studies have been performed across the world in recent decades. This paper illustrates the effects of particle size on the PTE contents, [...] Read more.
Because of the rising environmental and health concerns associated with atmospheric pollution caused by potentially toxic elements (PTEs), several road dust studies have been performed across the world in recent decades. This paper illustrates the effects of particle size on the PTE contents, mineralogical composition, environmental pollution and health risk assessments in road dust from Barcelona (Spain). The samples were sieved into five size fractions ranging from <45 to 500–800 µm. Although the major mineral contents (tectosilicates, phyllosilicates, and carbonates) were profuse in all fractions, the identified inhalable PTE particles (e.g., Fe, Cr, Cu, Zn, Ni, and REE), with size < 10 µm, were more pervasive in the finest fraction (<45 μm). This is consistent with the concentrations measured: the finest fractions were richer in PTEs than the coarser ones, resulting in a direct correlation with the enrichment factor (EFx), geo-accumulation (Igeo), and non-carcinogenic (HI) and carcinogenic (CRI) values. Igeo and EFx values can be appropriate tracers for some common elements (e.g., Zn, Sb, Sn, Cu, and Cr), but they do not seem adequate for anthropogenic particles accumulated at concentrations similar to the geogenic background. Overall, the HI and CRI values obtained in Barcelona were acceptable, reflecting no serious health impacts in the study area, except for Cr. Our results suggest that fine dust particles are a more suitable fraction to conduct pollution and health risk assessments than coarser ones, although the EFx, Igeo, HI, and CRI threshold values should be redefined in the future to include all emergent pollutants as well. In summary, monitoring programs should include at least the road dust evaluation of <45 µm particles, which can be performed with a simple sieving method, which is both time- and cost-effective. Full article
Show Figures

Graphical abstract

10 pages, 3324 KiB  
Article
Diffuse and Direct UV Index Experimental Values
by María J. Marín, Víctor Estellés, José L. Gómez-Amo and María P. Utrillas
Atmosphere 2023, 14(8), 1221; https://doi.org/10.3390/atmos14081221 - 28 Jul 2023
Cited by 1 | Viewed by 1367
Abstract
In this work, we study the different components of the UV Index, direct, diffuse, and global, for seven years of UV erythemal measurements in a Mediterranean locality at Burjassot AtmoSpheric Station (BASS). The measurements have been taken with three YES-UVB-1 radiometers: one provided [...] Read more.
In this work, we study the different components of the UV Index, direct, diffuse, and global, for seven years of UV erythemal measurements in a Mediterranean locality at Burjassot AtmoSpheric Station (BASS). The measurements have been taken with three YES-UVB-1 radiometers: one provided with a shadow disk on a Sun tracker; a radiometer to measure the global horizontal radiation; and a Sun-tracking radiometer to measure the direct radiation with an especially designed radiance collimator. It is known that diffuse UV irradiance represents at least 50% of total UV irradiance on a horizontal plane, which means being able to obtain a high UV Index even under shade. Our study aims to establish the relationship between the UV Index at noon and the maximum daily UV erythemal irradiance in the mid-latitude area, as well as the potential erythemal effects of exposure to solar UV radiation on different skin phototypes (skin phototypes I–IV) for both direct and diffuse components. Full article
(This article belongs to the Section Biometeorology and Bioclimatology)
Show Figures

Figure 1

24 pages, 2963 KiB  
Article
Repeatedly Northwards and Upwards: Southern African Grasslands Fuel the Colonization of the African Sky Islands in Helichrysum (Compositae)
by Carme Blanco-Gavaldà, Mercè Galbany-Casals, Alfonso Susanna, Santiago Andrés-Sánchez, Randall J. Bayer, Christian Brochmann, Glynis V. Cron, Nicola G. Bergh, Núria Garcia-Jacas, Abel Gizaw, Martha Kandziora, Filip Kolář, Javier López-Alvarado, Frederik Leliaert, Rokiman Letsara, Lucía D. Moreyra, Sylvain G. Razafimandimbison, Roswitha Schmickl and Cristina Roquet
Plants 2023, 12(11), 2213; https://doi.org/10.3390/plants12112213 - 3 Jun 2023
Cited by 3 | Viewed by 3018
Abstract
The Afromontane and Afroalpine areas constitute some of the main biodiversity hotspots of Africa. They are particularly rich in plant endemics, but the biogeographic origins and evolutionary processes leading to this outstanding diversity are poorly understood. We performed phylogenomic and biogeographic analyses of [...] Read more.
The Afromontane and Afroalpine areas constitute some of the main biodiversity hotspots of Africa. They are particularly rich in plant endemics, but the biogeographic origins and evolutionary processes leading to this outstanding diversity are poorly understood. We performed phylogenomic and biogeographic analyses of one of the most species-rich plant genera in these mountains, Helichrysum (Compositae-Gnaphalieae). Most previous studies have focused on Afroalpine elements of Eurasian origin, and the southern African origin of Helichrysum provides an interesting counterexample. We obtained a comprehensive nuclear dataset from 304 species (≈50% of the genus) using target-enrichment with the Compositae1061 probe set. Summary-coalescent and concatenation approaches combined with paralog recovery yielded congruent, well-resolved phylogenies. Ancestral range estimations revealed that Helichrysum originated in arid southern Africa, whereas the southern African grasslands were the source of most lineages that dispersed within and outside Africa. Colonization of the tropical Afromontane and Afroalpine areas occurred repeatedly throughout the Miocene–Pliocene. This timing coincides with mountain uplift and the onset of glacial cycles, which together may have facilitated both speciation and intermountain gene flow, contributing to the evolution of the Afroalpine flora. Full article
(This article belongs to the Section Plant Systematics, Taxonomy, Nomenclature and Classification)
Show Figures

Figure 1

35 pages, 524 KiB  
Article
Examining the Potential of Marine Renewable Energy: A Net Energy Perspective
by Roger Samsó, Júlia Crespin, Antonio García-Olivares and Jordi Solé
Sustainability 2023, 15(10), 8050; https://doi.org/10.3390/su15108050 - 15 May 2023
Cited by 5 | Viewed by 3258
Abstract
It is often claimed that marine renewable energy alone could meet the electricity demand of current and future human societies. However, such claims are based on highly uncertain estimations of the global potentials of marine renewable energy sources (including tidal, ocean currents, wave, [...] Read more.
It is often claimed that marine renewable energy alone could meet the electricity demand of current and future human societies. However, such claims are based on highly uncertain estimations of the global potentials of marine renewable energy sources (including tidal, ocean currents, wave, offshore wind and salinity and thermal gradients), and do not take into account the embedded energy of current technologies. To better understand the effective potential of marine energy, we conducted a literature review of its gross, technical, economic and sustainable potentials, as well as the energy return on investment (EROI), and estimated the net energy potential. We found that all marine technologies could provide a maximum energy surplus of 57,000 TWh/yr. This figure goes down to 5000TWh/yr when excluding offshore wind. The previous figures do not include the contribution from ocean currents, for which no reliable estimates of global potentials and EROIs could be obtained. Due to its high upfront costs and environmental impacts and low social acceptance, no additional tidal range capacity expansion is envisioned. Similarly, the combination of a low sustainable potential and the low EROI makes the large-scale exploitation of salinity gradients unlikely with current technologies. Including all technologies, the average EROI of marine energy is 20, but excluding offshore wind reduces the average EROI to 8. While we did consider sustainability constraints for some marine energy sources, our estimation of marine net energy potential primarily relied on technical factors and did not account for economic and legal constraints. Therefore, the results presented here should be interpreted as an upper bound for the actual net energy contribution of marine energy sources to the global energy mix. Full article
Show Figures

Figure 1

36 pages, 21824 KiB  
Article
Rockfall Magnitude-Frequency Relationship Based on Multi-Source Data from Monitoring and Inventory
by Marc Janeras, Nieves Lantada, M. Amparo Núñez-Andrés, Didier Hantz, Oriol Pedraza, Rocío Cornejo, Marta Guinau, David García-Sellés, Laura Blanco, Josep A. Gili and Joan Palau
Remote Sens. 2023, 15(8), 1981; https://doi.org/10.3390/rs15081981 - 9 Apr 2023
Cited by 8 | Viewed by 2704
Abstract
Quantitative hazard analysis of rockfalls is a fundamental tool for sustainable risk management, even more so in places where the preservation of natural heritage and people’s safety must find the right balance. The first step consists in determining the magnitude-frequency relationship, which corresponds [...] Read more.
Quantitative hazard analysis of rockfalls is a fundamental tool for sustainable risk management, even more so in places where the preservation of natural heritage and people’s safety must find the right balance. The first step consists in determining the magnitude-frequency relationship, which corresponds to the apparently simple question: how big and how often will a rockfall be detached from anywhere in the cliff? However, there is usually only scarce data on past activity from which to derive a quantitative answer. Methods are proposed to optimize the exploitation of multi-source inventories, introducing sampling extent as a main attribute for the analysis. This work explores the maximum possible synergy between data sources as different as traditional inventories of observed events and current remote sensing techniques. Both information sources may converge, providing complementary results in the magnitude-frequency relationship, taking advantage of each strength that overcomes the correspondent weakness. Results allow characterizing rockfall detachment hazardous conditions and reveal many of the underlying conditioning factors, which are analyzed in this paper. High variability of the hazard over time and space has been found, with strong dependencies on influential external factors. Therefore, it will be necessary to give the appropriate reading to the magnitude-frequency scenarios, depending on the application of risk management tools (e.g., hazard zoning, quantitative risk analysis, or actions that bring us closer to its forecast). In this sense, some criteria and proxies for hazard assessment are proposed in the paper. Full article
(This article belongs to the Special Issue Remote Sensing for Rock Slope and Rockfall Analysis)
Show Figures

Figure 1

23 pages, 3402 KiB  
Article
A Machine Learning Approach to Derive Aerosol Properties from All-Sky Camera Imagery
by Francesco Scarlatti, José L. Gómez-Amo, Pedro C. Valdelomar, Víctor Estellés and María Pilar Utrillas
Remote Sens. 2023, 15(6), 1676; https://doi.org/10.3390/rs15061676 - 20 Mar 2023
Cited by 3 | Viewed by 2253
Abstract
We propose a methodology to derive the aerosol optical depth (AOD) and Angstrom exponent (AE) from calibrated images of an all-sky camera. It is based on a machine learning (ML) approach that establishes a relationship between AERONET measurements of AOD and AE and [...] Read more.
We propose a methodology to derive the aerosol optical depth (AOD) and Angstrom exponent (AE) from calibrated images of an all-sky camera. It is based on a machine learning (ML) approach that establishes a relationship between AERONET measurements of AOD and AE and different signals derived from the principal plane radiance measured by an all-sky camera at three RGB channels. Gaussian process regression (GPR) has been chosen as machine learning method and applied to four models that differ in the input choice: RGB individual signals to predict spectral AOD; red signal only to predict spectral AOD and AE; blue-to-red ratio (BRR) signals to predict spectral AOD and AE; red signals to predict spectral AOD and AE at once. The novelty of our approach mostly relies on obtaining a cloud-screened and smoothed signal that enhances the aerosol features contained in the principal plane radiance and can be applied in partially cloudy conditions. In addition, a quality assurance criterion for the prediction has been also suggested, which significantly improves our results. When applied, our results are very satisfactory for all the models and almost all predictions are close to real values within ±0.02 for AOD and ±0.2 for AE, whereas the MAE is less than 0.005. They show an excellent agreement with AERONET measurements, with correlation coefficients over 0.92. Moreover, more than 87% of our predictions lie within the AERONET uncertainties (±0.01 for AOD, ±0.1 for AE) for all the output parameters of the best model. All the models offer a high degree of numerical stability with negligible sensitivities to the training data, atmospheric conditions and instrumental issues. All this supports the strength and efficiency of our models and the potential of our predictions. The optimum performance shown by our proposed methodology indicates that a well-calibrated all-sky camera can be routinely used to accurately derive aerosol properties. Together, all this makes the all-sky cameras ideal for aerosol research and this work may represent a significant contribution to the aerosol monitoring. Full article
(This article belongs to the Section AI Remote Sensing)
Show Figures

Figure 1

15 pages, 1443 KiB  
Perspective
Climate and Energy Crises from the Perspective of the Intergovernmental Panel on Climate Change: Trade-Offs between Systemic Transition and Societal Collapse?
by Jordi Solé
Sustainability 2023, 15(3), 2231; https://doi.org/10.3390/su15032231 - 25 Jan 2023
Cited by 8 | Viewed by 2681
Abstract
AR6 IPCC reports give divergent messages about the different socio-economic transition approaches to deal with the current climate emergency. The dangers of not giving a clear message to policymakers and to society on the need of changing the current socio-economic paradigm are considerable: [...] Read more.
AR6 IPCC reports give divergent messages about the different socio-economic transition approaches to deal with the current climate emergency. The dangers of not giving a clear message to policymakers and to society on the need of changing the current socio-economic paradigm are considerable: to fall in the SSP3-7.0 scenario, which is conducive to the collapse of our current civilization. In this work, key variables to assess the main functionalities of global socio-economy are analyzed under a system dynamics approach. This allows for understanding what the evolution is of our current socio-economy in a framework of climate change and resource depletion. The aim of this work is to provide a different perspective on socio-economic evolution by identifying similar characteristics in the worst-case IPCC scenarios with historical behavior in complex societies. From such a historical perspective and the current system evolution, a conceptual model is proposed to explain our globalized complex system near to a phase transition. Then, phase transition correspondences from the model to the current socio-economic system are proposed and a series of corresponding preventive measures (in terms of social actions, economic measures, and their linked policies) are suggested to avoid collapse scenarios. Full article
Show Figures

Figure 1

30 pages, 8495 KiB  
Article
Machine Learning-Based Rockfalls Detection with 3D Point Clouds, Example in the Montserrat Massif (Spain)
by Laura Blanco, David García-Sellés, Marta Guinau, Thanasis Zoumpekas, Anna Puig, Maria Salamó, Oscar Gratacós, Josep Anton Muñoz, Marc Janeras and Oriol Pedraza
Remote Sens. 2022, 14(17), 4306; https://doi.org/10.3390/rs14174306 - 1 Sep 2022
Cited by 9 | Viewed by 3106
Abstract
Rock slope monitoring using 3D point cloud data allows the creation of rockfall inventories, provided that an efficient methodology is available to quantify the activity. However, monitoring with high temporal and spatial resolution entails the processing of a great volume of data, which [...] Read more.
Rock slope monitoring using 3D point cloud data allows the creation of rockfall inventories, provided that an efficient methodology is available to quantify the activity. However, monitoring with high temporal and spatial resolution entails the processing of a great volume of data, which can become a problem for the processing system. The standard methodology for monitoring includes the steps of data capture, point cloud alignment, the measure of differences, clustering differences, and identification of rockfalls. In this article, we propose a new methodology adapted from existing algorithms (multiscale model to model cloud comparison and density-based spatial clustering of applications with noise algorithm) and machine learning techniques to facilitate the identification of rockfalls from compared temporary 3D point clouds, possibly the step with most user interpretation. Point clouds are processed to generate 33 new features related to the rock cliff differences, predominant differences, or orientation for classification with 11 machine learning models, combined with 2 undersampling and 13 oversampling methods. The proposed methodology is divided into two software packages: point cloud monitoring and cluster classification. The prediction model applied in two study cases in the Montserrat conglomeratic massif (Barcelona, Spain) reveal that a reduction of 98% in the initial number of clusters is sufficient to identify the totality of rockfalls in the first case study. The second case study requires a 96% reduction to identify 90% of the rockfalls, suggesting that the homogeneity of the rockfall characteristics is a key factor for the correct prediction of the machine learning models. Full article
(This article belongs to the Section Remote Sensing in Geology, Geomorphology and Hydrology)
Show Figures

Figure 1

9 pages, 4216 KiB  
Communication
Revisiting the Raractocetus Fossils from Mesozoic and Cenozoic Amber Deposits (Coleoptera: Lymexylidae)
by Yan-Da Li, David Peris, Shûhei Yamamoto, Yun Hsiao, Alfred F. Newton and Chen-Yang Cai
Insects 2022, 13(9), 768; https://doi.org/10.3390/insects13090768 - 25 Aug 2022
Cited by 3 | Viewed by 2305
Abstract
The fossils once assigned to Raractocetus Kurosawa from the Mesozoic and Cenozoic amber deposits differ from extant Raractocetus in the longer elytra, the more strongly projecting metacoxae, and the hind wing with vein 2A forked. Thus, these fossils should be removed from Raractocetus [...] Read more.
The fossils once assigned to Raractocetus Kurosawa from the Mesozoic and Cenozoic amber deposits differ from extant Raractocetus in the longer elytra, the more strongly projecting metacoxae, and the hind wing with vein 2A forked. Thus, these fossils should be removed from Raractocetus. Cretoquadratus engeli Chen from Kachin amber appears to be conspecific with R. fossilis Yamamoto. As a result, R. fossilis and R. extinctus Yamamoto from Kachin amber, R. balticus Yamamoto from Baltic amber, and R. sverlilo Nazarenko, Perkovsky & Yamamoto from Rovno amber are transferred to Cretoquadratus Chen, as C. fossilis (Yamamoto) comb. nov., C. extinctus (Yamamoto) comb. nov., C. balticus (Yamamoto) comb. nov., and C. sverlilo (Nazarenko, Perkovsky & Yamamoto) comb. nov., and C. engeli syn. nov. is suggested to be a junior synonym of C. fossilis. Full article
(This article belongs to the Special Issue Beetle Diversity)
Show Figures

Figure 1

32 pages, 14096 KiB  
Article
Water Circulation and Transport Time Scales in the Beagle Channel, Southernmost Tip of South America
by Andrea Cucco, Jacobo Martín, Giovanni Quattrocchi, Harold Fenco, Georg Umgiesser and Daniel Alfredo Fernández
J. Mar. Sci. Eng. 2022, 10(7), 941; https://doi.org/10.3390/jmse10070941 - 8 Jul 2022
Cited by 13 | Viewed by 2608
Abstract
The Beagle Channel is a long and narrow interoceanic passage within the Tierra del Fuego archipelago in the southernmost tip of South America. A high-resolution 3D hydrodynamic model based on the finite elements method was applied to investigate the residual circulation, water fluxes [...] Read more.
The Beagle Channel is a long and narrow interoceanic passage within the Tierra del Fuego archipelago in the southernmost tip of South America. A high-resolution 3D hydrodynamic model based on the finite elements method was applied to investigate the residual circulation, water fluxes and transport time scales inside this channel. Numerical solutions were analyzed at seasonal time scale and the model results compared with observed ocean data. The circulation pattern is characterized by a west-to-east residual flow with low intensity and low seasonal variability. The water fluxes through the channel were estimated to be, on average, around 12,700 m3/s, with inflow through its western entrance and eastwards outflow mainly through the Mackinlay Strait. The water residence times vary seasonally with basin averages between 36 and 43 days and maximum values between 53 and 95 days. The results provide an overview of the hydrodynamics and water residence times in the Beagle Channel, a unique ecosystem threatened by recent anthropogenic pressures and climate change. Full article
(This article belongs to the Special Issue Dynamics in Coastal Areas)
Show Figures

Figure 1

Back to TopTop