<p>Marine atmosphere boundary layer (MABL) water vapor amount and gradient impact global energy transport through directly affecting the sensible and latent heat exchange between the ocean and atmosphere. Yet, it is a well-known challenge for satellite remote sensing to profile MABL water vapor, especially when cloud or a sharp vertical gradient of water vapor is present. <span class="cit" id="xref_text.1"><a href="#bib1.bibx36">Wu et al.</a> (<a href="#bib1.bibx36">2022</a>)</span> identified good correlations between the Global Navigation Satellite System (GNSS) deep refraction signal-to-noise-ratio (SNR) value and the global MABL water vapor specific humidity when the radio occultation (RO) signal is ducted by the moist planetary boundary layer (PBL), and they laid out the underlying physical mechanisms to explain such a correlation. In this work, we apply a machine learning/artificial intelligence (ML/AI) technique to demonstrate the feasibility of profile-by-profile MABL water vapor retrieval using the SNR signal. Three convolutional neural network (CNN) models are trained using multi-months of global collocated hourly ERA-5 reanalysis and COSMIC-1, Metop-A, and Metop-B 1 Hz SNR observations between 975–850 hPa with 25 hPa vertical resolution. The COSMIC-1 ML model is then applied to both COSMIC-1 and COSMIC-2 in other time ranges for independent retrieval and validation. The Monte Carlo Dropout method was employed for the uncertainty estimation. Comparison against multiple field campaign radiosonde/dropsonde observations globally suggests that SNR-ML-method-retrieved water vapor consistently outperforms the wetPrf/wetPf2 standard retrieval product at all six pressure levels between 975 and 850 hPa and either outperforms or achieves similar performance against ERA-5, indicating real and useful information is gained from the SNR signal, though training was performed against the reanalysis. The climatology and diurnal cycle of MABL structure constructed from the SNR-ML technique are studied and compared to the reanalysis. Disparities of climatology suggest ERA-5 may systematically produce dry biases at high latitudes and wet biases in marine stratocumulus regions. The diurnal cycle amplitudes are too weak and sometimes off phase in ERA-5, especially in the Arctic and stratocumulus regions. These areas are particularly prone to PBL processes, where this GNSS SNR-ML water vapor product may contribute the most.</p>
<p>As part of the Pandonia Global Network (PGN), Pandora spectrometers are widely deployed around the world. These ground-based remote-sensing instruments are federated such that they employ a common algorithm and data protocol for reporting on trace gas column densities and lower-atmospheric profiles using two modes based on direct-sun and sky-scan observations. To aid users in the analysis of Pandora observations, the PGN standard quality flagging procedure assigns flags to the data indicating high, medium, and low quality. This work assesses the suitability of these data quality flags for filtering data in the scientific analysis of formaldehyde (HCHO) and nitrogen dioxide (<span class="inline-formula">NO<sub>2</sub></span>), two critical precursors controlling tropospheric ozone production. Pandora data flagged as high quality assure scientifically valid data and are often more abundant for direct-sun <span class="inline-formula">NO<sub>2</sub></span> columns. For direct-sun HCHO and for sky-scan observations of both molecules, large amounts of data flagged as low quality also appear to be valid. Upon closer inspection of the data, independent uncertainty is shown to be a better indicator of data quality than the standard quality flags. After applying a filter to independent uncertainty, Pandora data flagged as medium or low quality in both modes can be demonstrated to be scientifically useful. The utility of this filtering method is demonstrated by correlating contemporaneous but independent direct-sun and sky-scan observations. When evaluated across 15 Pandora sites in North America, this new filtering method can recover as much as 90 % of data that would have previously been discarded. This method suggests that standard PGN criteria for atmospheric variability and the normalized root mean squared error are too stringent, as they are responsible for downgrading most of the recovered data. A method is also developed for combining the direct-sun and sky-scan observations into a single dataset by accounting for biases between the two observing modes and differences in measurement integration times. These combined data provide a more continuous record that is useful for interpreting Pandora observations against other independent variables such as hourly observations of surface ozone. When Pandora HCHO columns are correlated with surface ozone measurements, data filtered by independent uncertainty exhibit similarly strong and more robust relationships than high-quality data alone. These results suggest that Pandora data users should carefully assess data across all quality flags and consider their potential for useful application to scientific analysis. The present study provides a method for maximizing use of Pandora data with the expectation of more robust satellite validation and comparisons with ground-based observations in support of air quality studies.</p>
<p>The Infrared Atmospheric Sounder Interferometer (IASI) is a Fourier Transform Spectrometer onboard the Eumetsat MetOp (Meteorological Operational) polar orbit satellite series. The three MetOp satellites (A, B, and C) were launched in October 2006, September 2012 and November 2018, respectively. IASI-B and IASI-C are still operational, while IASI-A was decommissioned in November 2021. IASI's mission is to provide accurate atmospheric spectra primarily for meteorological and climate applications, and as such a high measurement precision is required. Furthermore, the estimation of the measurement uncertainty is a valuable element, especially concerning climate studies and the establishment of long climate series. This study presents the global radiometric uncertainty budget as estimated for the IASI instruments. Four major contributors, the correction of the analog non-linearity, the black body characterization, the scan mirror reflectivity, and the background radiance instability, have been identified and their impact is presented alongside other minor contributors. For black body or earth view scenes under investigation, the global budget was found to be lower than 0.2 <span class="inline-formula">K</span> for a reference temperature of 280 <span class="inline-formula">K</span>, when all uncertainties were considered fully correlated. These estimates are expected to remain relatively stable throughout the instrument lifetime.</p>
<p>Black carbon (BC) is one of the most important climate forcers with severe health effects. Large uncertainties in radiative forcing estimation and health impact assessment arise from the fact that there is no standardized method to measure BC mass concentration. This study presents a 2-year comparison of three state-of-the-art BC measurement techniques at the high-altitude research station Pic du Midi (PDM) located in the French Pyrenees at an altitude of 2877 <span class="inline-formula">m</span> above sea level. A recently upgraded Aethalometer AE33, a thermal-optical analyser Sunset and a single-particle soot photometer SP2 were deployed to measure simultaneously the mass concentration of equivalent black carbon (<span class="inline-formula"><i>M</i><sub>eBC</sub></span>), elemental carbon (<span class="inline-formula"><i>M</i><sub>EC</sub></span>) and refractory black carbon (<span class="inline-formula"><i>M</i><sub>rBC</sub></span>), respectively. Significant deviations in the response of the instruments were observed. All techniques responded to seasonal variations in the atmospheric changes in BC levels and exhibited good correlation during the whole study period. This indicates that the different instruments quantified the same particle type despite the fact that they are based on different physical principles. However the slopes and correlation coefficients varied between instrument pairs. The largest biases were observed for the AE33 with <span class="inline-formula"><i>M</i><sub>eBC</sub></span> values that were around 2 times greater than <span class="inline-formula"><i>M</i><sub>rBC</sub></span> and <span class="inline-formula"><i>M</i><sub>EC</sub></span> values. The principal reasons of such large discrepancy were explained by the mass absorption cross section (MAC) that was too low and <span class="inline-formula"><i>C</i></span> values recommended by the AE33 manufacturer and applied to the absorption coefficients measured by the AE33. In addition, the long-range transport of dust particles at PDM in spring caused significant increases in the bias between AE33 and SP2 by up to a factor 8. The Sunset <span class="inline-formula"><i>M</i><sub>EC</sub></span> measurements agreed within around 17 % with the SP2 <span class="inline-formula"><i>M</i><sub>rBC</sub></span> values. The largest overestimations of <span class="inline-formula"><i>M</i><sub>EC</sub></span> were observed when the total carbon concentrations were below 25 <span class="inline-formula">µg C cm<sup>−2</sup></span>, which is probably linked to the incorrect determination of the organic carbon (OC)–EC split point. Another cause of the discrepancy between instruments was found to be the limited detection range of the SP2, which did not allow for the total detection of fine rBC particles. The procedure used to estimate the missing mass fraction of rBC not covered by the measurement range of the SP2 was found to be critical. We found that a time-dependent correction based on fitting the observed rBC size distribution with a multimodal lognormal distribution is needed to accurately estimate <span class="inline-formula"><i>M</i><sub>rBC</sub></span> over a larger size range.</p>
The issue of choosing a structural design and material for supporting structures is an important technical and economic task at the stage of developing a design solution. It depends on a number of factors: consequence class of the structure, reliability of the design solution, savings in basic building materials. The publication provides a classification of design schemes and types of load-bearing structures used in the corresponding solutions. The disadvantages and advantages of using prefabricated and monolithic structures for the installation and subsequent operation of the structural scheme of buildings and structures are considered. Modern design requirements include ensuring the ability of a damaged structure to adapt to new conditions while continuing to function while ensuring the integrity of human life, property and equipment. New conditions mean the consequences of the occurrence of a certain emergency situation, accompanied by weakening or overloading of the load-bearing structures of a structure or soil foundation: a change in the structural design, a combination of new existing loads and a redistribution of internal forces. The publication reflects the results of assessing the redistribution of the stress-strain state of the elements of the “base - foundations - load-bearing structures” system as a result of the implementation of a hypothetical emergency situation with the exclusion of the load-bearing structure from operation. The case of the collapse of one of the vertical load-bearing elements (local failure of the pylon) of an underground floor, which can be used as a dual-use structure, is considered. Calculations for the stability of the structure against progressive collapse were carried out by numerical modeling in the LIRA SAPR-2019 software using a quasi-static calculation and the method of direct integration of dynamics over time. It has been demonstrated that the method of numerical modeling the joint work of a building with a soil base affects the results of a calculation of the progressive collapse of the building frame. The influence of local collapse of a vertical load-bearing element on the redistribution of stresses and strains in the foundation structures of a building section is assessed. The load on the piles under the pylons around the element removed under the local failure scenario is expected to increase by 15...25%.
The results of numerical modeling of the interaction between a pile retaining wall and the soil base using the software complexes "Plaxis" and "LIRA-SAPR" are presented. A comparison of the stress-strain state of retaining walls using different calculation methods, taking into account the presence of rock soil, has been performed. In the first variant, the active pressure on the wall was determined manually in accordance with the current standards [3], and the subsequent calculation was carried out in the "LIRA-SAPR" software complex. The "pile-soil" system was modeled using FE 57, which are interconnected by FE 10 (rod), and the values of horizontal stiffness (Rx,y) were determined according to the requirements of [3]. In the second variant, the retaining wall calculation was performed in "Plaxis 2D". The soil behavior model is "Mohr-Coulomb", and for rock - "Hoek-Brown". It was considered that rock soils lie at the base of the retaining wall, which revealed significant differences in the distribution of bending moments along the length of the retaining wall. It was established that the stress-strain state in the first variant significantly differs from the second. The difference in maximum horizontal displacements after the calculation by the first and second methods was shown. Differences and variations in the values of bending moments occurring in the retaining wall were investigated. The importance of using modern geotechnical calculation software complexes for a more detailed and accurate analysis of structures and foundations was demonstrated. Additionally, an assessment of the impact of variations in the parameters of the soil and retaining wall models on the calculation results was conducted. The research results allow recommending the use of a comprehensive modeling approach to enhance the reliability and efficiency of retaining wall design. The analysis also shows that the application of different soil behavior models can significantly affect the final calculation results, highlighting the need for careful selection of modeling parameters. The obtained results have significant practical value for engineers and designers, as they allow for more accurate prediction of the behavior of retaining walls under various operating conditions. This contributes to improving the safety and cost-effectiveness of construction projects.
In modern realities, the construction of multi-story buildings increasingly has to be carried out in the conditions of dense urban development. Since high-rise buildings are characterized by the presence of deep pits, there is a need to select the parameters of the enclosing structures (retaining walls) and take into account the influence of the pit arrangement and enclosing structures on the existing building. Numerical simulation of the stress-strain state (SSS) of the elements "soil base - existing structures - pit enclosure" was performed to assess the impact of choosing the dimensions of the calculation scheme when designing a deep pit and assessing its impact on existing buildings and selecting effective parameters of enclosing structures. with different dimension options (flat two-dimensional and spatial three-dimensional) calculation scheme. Modeling was performed using the finite element method using a nonlinear model of soil deformation in the Plaxis software package. Since the soil conditions within the construction site are complex (the presence of a significant layer of plastic and flowing clay soils and powerful aquifers), the level of groundwater within the construction site was taken into account in the modeling and the effect of water lowering during the development of the pit was modeled accordingly for a more correct assessment of the stress-strained state of pit enclosure elements and the impact on existing structures. Numerical calculations of retaining walls provide for taking into account the technological sequence of the construction of retaining walls and modeling of the step-by-step development of the pit. Studies have shown that the use of a spatial finite-element model of the system "soil base - existing structures - pit enclosure" provides an opportunity to more correctly and effectively assess the stress-deformed state of system elements due to taking into account the spatial rigidity of the elements of the pit enclosure and the foundations of existing structures. The values of the displacements of the retaining walls obtained by the calculation of the spatial finite element model (FEM) are 20% smaller than the values obtained using the plane FEM. The values of the bending moments obtained by the calculation of the spatial FEM are 10% smaller than the values obtained using the plane FEM.
Compaction is essential in earthworks of civil infrastructures, such as dam embankments, building foundations, roads, and other transport infrastructures. The nuclear method is a non-destructive test that has been one of the most used field tests in the quality control of compaction for a long time due to its easy operation and accuracy. The technique uses nuclear equipment to measure soil and aggregates' moisture content and in-situ density. The fidelity of the method according to Portuguese technology is still unknown. The paper has two main objectives: (1) to describe the application of the non-destructive testing method to the quality control of compaction; (2) to present the repeatability and reproducibility of the method in its application to the case of soils based on proficiency tests. The paper presents the methodology followed in carrying out the proficiency tests and analysing the results related to the method's fidelity. The work points out the most critical aspects of the test and presents the repeatability and reproducibility related to in situ density and moisture content in the cases of direct transmission and backscatter measurements.
The article presents a continuum approach to predict the response of pile foundations for jacket-supported offshore wind turbines. Tensile loading conditions are examined, which may be critical for piles used in combination with this structure type, generally adopted to exploit wind energy in intermediate water depths. The approach is developed to guarantee a simple implementation with a limited number of input data easily attainable from cone penetration tests and laboratory tests, and to ensure computational cost-effectiveness. Data from technical-scale tests on open-ended steel piles driven in dense sand and subjected to drained pull-out are used to assess the performance of the approach. The results are shown to be accurate, approximating rather closely the experimental load– displacement curves. The accuracy of the approach is also compared to that obtained with a recently proposed design method, to investigate the predictive capacity of the approach and its potential to support preliminary design activities. (cid:1) 2023 Production and hosting by Elsevier B.V. on behalf of The Japanese Geotechnical Society. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Card game creation is a powerful tool for game design. Using playing cards, game designers can rapidly prototype and iteratively playtest a game’s core mechanisms to explore alternatives and improve the gameplay. However, this process is time-consuming, imprecise and challenging to steer and focus. We aim to empower designers with solutions that automate game design processes. In particular, we study to what extent a unified game design language can offer theoretical foundations, systematic techniques and practical solutions. We propose a novel approach towards a solution that leverages the expressive power of playing cards. Initially focusing on well-known card games, we illustrate the steps for creating CardScript, a formal language and toolkit that supports game design processes. The approach also has the potential to impact a wider research area. When fully developed, a unified language with a common tool set can enable reuse, and eventually support joint research agendas. We start the discussion by highlighting perspectives that relate open challenges to opportunities for future collaboration.
In addition to natural curiosity, science is characterized by a number of psychological processes and perceptions. Among the psychological features, scientific enquiry relates to uncovering—or discovering—aspects of a world perceived as hidden from humans. A speculative theoretical model is presented, suggesting the evolution of science reflects psychological repercussions of wearing clothes. Specifically, the natural world is perceived as hidden due to the presence of clothing. Three components of scientific enquiry may arise from clothing: detachment from sensual experience, a perception that the world is veiled in mystery, and an intellectual desire to uncover the hidden structure of nature. Rather than beginning with the emergence of Homo sapiens, the proposed connection with clothing implies that psychological foundations for science began to develop during the last ice age, with the invention of complex clothes that fully covered the human body. After the end of the last ice age, elements of scientific thinking began to emerge in societies where clothing was worn routinely for psychosocial reasons, including modesty. Notably, a scientific attitude was essentially absent in hunter-gatherer communities where nakedness remained the norm. This novel perspective aims to advance the history and philosophy of science, revealing the emergence of science as a situated phenomenon contingent on humans being covered.
A. Tulebekova, G. Tanyrbergenova, A. Zhankina
et al.
The application of methods of improvement of ground bases in subsidence areas is an urgent issue today. This is evidenced by the continuing difficulties with the operation of transport structures. This study presents experimental studies of soil reinforcement. An important factor is to determine the properties of the soil, so the paper presents the results of laboratory tests. The angle of internal friction and the deformation increases to a greater extent when the reinforcing element is embedded in the ground, which will increase the bearing capacity of the foundations and reduce the deformability and settlement of the soil mass. The use of a reinforcing element in the ground not only makes it possible to improve the physical and mechanical properties of the soil but also gives an economic effect. It allows you to reduce the cost of the volume of earthworks. The results obtained in this study have considerable potential for eliminating problems arising from the construction of structures in subsidence areas.
T. C. V. W. Riess, K. F. Boersma, K. F. Boersma
et al.
<p>The sensitivity of satellites to air pollution close to the sea surface is decreased by the scattering of light in the atmosphere and low sea surface albedo. To reliably retrieve tropospheric nitrogen dioxide (NO<span class="inline-formula"><sub>2</sub></span>) columns using the TROPOspheric Monitoring Instrument (TROPOMI), it is therefore necessary to have good a priori knowledge of the vertical distribution of NO<span class="inline-formula"><sub>2</sub></span>. In this study, we use an aircraft of the Royal Belgian Institute of Natural Sciences equipped with a sniffer sensor system to measure NO<span class="inline-formula"><sub><i>x</i></sub></span> (<span class="inline-formula">=</span> NO <span class="inline-formula">+</span> NO<span class="inline-formula"><sub>2</sub></span>), CO<span class="inline-formula"><sub>2</sub></span> and SO<span class="inline-formula"><sub>2</sub></span>. This instrumentation enabled us to evaluate vertical profile shapes from several chemical transport models and to validate TROPOMI tropospheric NO<span class="inline-formula"><sub>2</sub></span> columns over the polluted North Sea in the summer of 2021. The aircraft sensor observes multiple clear signatures of ship plumes from seconds after emission to multiple kilometers downwind. Besides that, our results show that the chemical transport model Transport Model 5, Massively Parallel version (TM5-MP), which is used in the retrieval of the operational TROPOMI NO<span class="inline-formula"><sub>2</sub></span> data, tends to underestimate surface level pollution – especially under conditions without land outflow – while overestimating NO<span class="inline-formula"><sub>2</sub></span> at higher levels over the study region. The higher horizontal resolution in the regional CAMS (Copernicus Atmosphere Monitoring Service) ensemble mean and the LOTOS-EUROS (Long Term Ozone Simulation European Operational Smog) model improves the surface level pollution estimates. However, the models still systematically overestimate NO<span class="inline-formula"><sub>2</sub></span> levels at higher altitudes, indicating exaggerated vertical mixing and overall too much NO<span class="inline-formula"><sub>2</sub></span> in the models over the North Sea. When replacing the TM5 a priori NO<span class="inline-formula"><sub>2</sub></span> profiles with the aircraft-measured NO<span class="inline-formula"><sub>2</sub></span> profiles in the air mass factor (AMF) calculation, we find smaller recalculated AMFs. Subsequently, the retrieved NO<span class="inline-formula"><sub>2</sub></span> columns increase by 20 %, indicating a significant negative bias in the operational TROPOMI NO<span class="inline-formula"><sub>2</sub></span> data product (up to v2.3.1) over the North Sea. This negative bias has important implications for estimating emissions over the sea. While TROPOMI NO<span class="inline-formula"><sub>2</sub></span> negative biases caused by the TM5 a priori profiles have also been reported over land, the reduced vertical mixing and smaller surface albedo over sea make this issue especially relevant over sea and coastal regions.</p>
<p>This study gives a systematic comparison of the Tropospheric Monitoring Instrument (TROPOMI) version 1.2 and Ozone Monitoring Instrument (OMI) QA4ECV tropospheric <span class="inline-formula">NO<sub>2</sub></span> column through global chemical data assimilation (DA) integration for the period April–May 2018. DA performance is controlled by measurement sensitivities, retrieval errors, and coverage. The smaller mean relative observation errors by 16 % in TROPOMI than OMI over 60<span class="inline-formula"><sup>∘</sup></span> N–60<span class="inline-formula"><sup>∘</sup></span> S during April–May 2018 led to larger reductions in the global root-mean-square error (RMSE) against the assimilated <span class="inline-formula">NO<sub>2</sub></span> measurements in TROPOMI DA (by 54 %) than in OMI DA (by 38 %). Agreements against the independent surface, aircraft-campaign, and ozonesonde observation data were also improved by TROPOMI DA compared to the control model simulation (by 12 %–84 % for <span class="inline-formula">NO<sub>2</sub></span> and by 7 %–40 % for ozone), which were more obvious than those by OMI DA for many cases (by 2 %–70 % for <span class="inline-formula">NO<sub>2</sub></span> and by 1 %–22 % for ozone) due to better capturing spatial and temporal variability by TROPOMI DA. The estimated global total <span class="inline-formula">NO<sub><i>x</i></sub></span> emissions were 15 % lower in TROPOMI DA, with 2 %–23 % smaller regional total emissions, in line with the observed negative bias of the TROPOMI version 1.2 product compared to the OMI QA4ECV product. TROPOMI DA can provide city-scale emission estimates, which were within 10 % differences with other high-resolution analyses for several limited areas, while providing a globally consistent analysis. These results demonstrate that TROPOMI DA improves global analyses of <span class="inline-formula">NO<sub>2</sub></span> and ozone, which would also benefit studies on detailed spatial and temporal variations in ozone and nitrate aerosols and the evaluation of bottom-up <span class="inline-formula">NO<sub><i>x</i></sub></span> emission inventories.</p>
Purpose The development of communication and artificial intelligence technologies has raised interest in connectivity and increased autonomy of automated earthmoving equipment for earthwork. These changes are motivating work to reduce uncertainties, in terms of improving equipment object detection capability and reducing strikes and accidents on site. The purpose of this study is to illustrate industrial drivers for automated earthwork systems; identify the specific capabilities which make the transformation happen; and finally determine use cases that create value for the system. These three objectives act as components of a technology roadmap for automated and connected earthwork and can guide development of new products and services. Design/methodology/approach This paper used a text mining approach in which the required data was captured through a structured literature review, and then expert knowledge was used for verification of the results. Findings Automated and connected earthwork can enhance construction site and its embraced infrastructure, resilience by avoiding human faults during operations. Automating the monitoring process can lead to reliable anticipation of problems and facilitate real-time responses to unexpected situation via connectedness capabilities. Research findings are presented in three sections: industrial perspectives, trends and drivers for automated and connected earthwork; capabilities which are met by technologies; and use cases to demonstrate different capabilities. Originality/value This study combines the results of disintegrated and fragmented research in the area of automated and connected earthwork and categorises them under new capability levels. The identified capabilities are classified in three main categories including reliable environmental perception, single equipment decision-making toward safe outcomes and fleet-level safety enhancement. Finally, four different levels of automation are proposed for earthwork technology roadmap.