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Abstract Observed trends in tropospheric ozone, an important air pollutant and short‐lived climate forcer (SLCF), are estimated using available surface and ozonesonde profile data for 1993–2019, using a coherent methodology, and compared to modeled trends (1995–2015) from the Arctic Monitoring Assessment Program SLCF 2021 assessment. Increases in observed surface ozone at Arctic coastal sites, notably during winter, and concurrent decreasing trends in surface carbon monoxide, are generally captured by multi‐model median trends. Wintertime increases are also estimated in the free troposphere at most Arctic sites, with decreases during spring months. Winter trends tend to be overestimated by the multi‐model medians. Springtime surface ozone increases in northern coastal Alaska are not simulated while negative springtime trends in northern Scandinavia are not always reproduced. Possible reasons for observed changes and model performance are discussed including decreasing precursor emissions, changing ozone dry deposition, and variability in large‐scale meteorology.

Classroom Shared Drawing (CSD) er et program, hvor undervisere kan lade studerende svare ved at tegne individuelt eller gruppevis. De studerendes svar samles i lag, så man hurtigt kan se de studerendes forståelser og misforståelser af et givent fagligt område eller spørgsmål og hvor mange svar der afviger fra det korrekte. De studerendes svar er anonyme, men kan også gøres ikke-anonyme og dermed tjene som en form for summativ evaluering eller screening. Programmets største styrke er dog som formativt evalueringsredskab, da det kan anvendes løbende i undervisningen til at afdække de studerendes viden og færdigheder. Programmet kan anvendes på flere taksonomiske niveauer og egner sig ikke kun som redskab i fag, hvor det at tegne udgør en del af fagligheden (f.eks. matematik og fysik) ifm. grafer, men kan med fordel anvendes i alle fag, hvis man eksempelvis vil bede studerende om at forbinde det korrekte svar til det stillede spørgsmål med streger.

Observations are reported of HClO3 and HClO4 in the atmosphere and their widespread occurrence over the pan-Arctic during spring, providing further insights into atmospheric chlorine cycling in the polar environment.

In this paper, three model-based fault diagnosis algorithms for robotic systems are designed, compared, simulated, and implemented. The first algorithm is based on a nonlinear adaptive observer (NLAO), where a sufficient condition for the convergence of the estimator is derived in terms of linear matrix inequality (LMI) under persistence of excitation condition. The second algorithm is based on an adaptive extended Kalman filter (AEKF). Unlike traditional approaches, where the fault parameters are considered as augmented state variables, the AEKF directly estimates the fault parameters from measurement data. The third algorithm is based on a cascade of a nonlinear observer (NLO) and a linearized adaptive Kalman filter (LAKF), called the adaptive exogenous Kalman filter (AXKF). The pros and cons for each algorithm are discussed. The performance of the algorithms is compared in a single-link joint robot system. Furthermore, the algorithms are implemented in a ball-balancing robot to detect and estimate the magnitude of the actuator faults.

Abstract The Arctic environment has changed profoundly in recent decades. Aerosol particles are involved in numerous feedback mechanisms in the Arctic, e.g., aerosol-cloud/radiation interactions, which have important climatic implications. To understand changes in different Arctic aerosol types and number concentrations, we have performed a trend analysis of particle number size distributions, their properties, and their associated air mass history at Villum Research Station, northeastern Greenland, from 2010 to 2018. We found that, during spring, the total/ultrafine mode number concentration and the time air masses spent over the open ocean is significantly increasing, which can be ascribed to transport patterns changing to more frequent arrival from the ice-free Greenland Sea. We found that, during summer, the total/ultrafine mode number concentration, the occurrence of the Nucleation cluster (i.e. newly formed particles from gas to particle conversion), and the time air masses spent over the open ocean is significantly increasing. This can also be attributed to changing transport patterns, here with air masses arriving more frequently from Baffin Bay. Finally, we found that, during autumn, the ultrafine number concentration and the occurrence of the Pristine cluster (i.e. clean, natural Arctic background conditions) is significantly increasing, which is likely due to increasing amounts of accumulated precipitation along the trajectory path and decreasing time air masses spent above the mixed layer, respectively. Our results demonstrate that changing circulation and precipitation patterns are the factors predominantly affecting the trends in aerosol particle number concentrations and the occurrence of different aerosol types in northeastern Greenland.

Arctic warming thaws permafrost, leading to enhanced soil mercury transport to the Arctic Ocean. Mercury isotope signatures in arctic rivers, ocean and atmosphere suggest that permafrost mercury is buried in marine sediment and not emitted to the global atmosphere

Recently, the term smartphone photogrammetry gained popularity. This suggests that photogrammetry may become a simple measurement tool by virtually every smartphone user. The research was undertaken to clarify whether it is appropriate to use the Structure from Motion—Multi Stereo View (SfM-MVS) procedure with self-calibration as it is done in Uncrewed Aerial Vehicle photogrammetry. First, the geometric stability of smartphone cameras was tested. Fourteen smartphones were calibrated on the checkerboard test field. The process was repeated multiple times. These observations were found: (1) most smartphone cameras have lower stability of the internal orientation parameters than a Digital Single-Lens Reflex (DSLR) camera, and (2) the principal distance and position of the principal point are constantly changing. Then, based on images from two selected smartphones, 3D models of a small sculpture were developed. The SfM-MVS method was used, with self-calibration and pre-calibration variants. By comparing the resultant models with the reference DSLR-created model it was shown that introducing calibration obtained in the test field instead of self-calibration improves the geometry of 3D models. In particular, deformations of local concavities and convexities decreased. In conclusion, there is real potential in smartphone photogrammetry, but it also has its limits.

Mangel på ingeniører og andre STEM-uddannede vækker bekymring i Europa. Og Danmark er blandt de lande, som er særligt udfordrede. Internationale studier tyder på, at matematiske evner har prædiktiv værdi i forhold til STEM-studerendes studiesucces – et begreb der omfatter både præstationer og progression på uddannelsen. I dette studie undersøges det, hvorvidt to matematiktests kan forudsige danske ingeniørstuderendes studieprogression; studiegennemførelse og beståelse af førsteårsprøven. De studerende havde ikke forberedt sig på test 1, mens de havde mulighed for at forberede sig på test 2. I forhold til den første test tyder studiets fund på, at det i højere grad er den frivillige deltagelse i undervisningen, hvori testen indgik end selve testscoren, der har sammenhæng med studiesuccesen. Pointscoren i den anden test viste sig at være en middelstærk prædiktor af både frafald og beståelse af førsteårsprøven. Studiet bidrager med input til diskussionen om optagelsestests på danske videregående uddannelser samt til ønsket om tidligt at kunne identificere frafaldstruede studerende.

The paper presents a pumpkin yield estimation method using images acquired by a UAV. The processing pipeline is fully automated. It consists of orthomosaic generation, a color model collection using a random subset of the data, color segmentation, and finally counting of pumpkin blobs together with assessing the number of pumpkins in each blob. The algorithm was validated by a manual check of 5% of each tested dataset. The precision value ranges between 0.959 and 0.996, recall between 0.971 and 0.987, and F1 score falls between 0.971 and 0.988. This proves the very high efficiency of the processing workflow and its potential value to farmers.

The Arctic is warming two to three times faster than the global average, and the role of aerosols is not well constrained. Aerosol number concentrations can be very low in remote environments, rendering local cloud radiative properties highly sensitive to available aerosol. The composition and sources of the climate-relevant aerosols, affecting Arctic cloud formation and altering their microphysics, remain largely elusive due to a lack of harmonized concurrent multi-component, multi-site, and multi-season observations. Here, we present a dataset on the overall chemical composition and seasonal variability of the Arctic total particulate matter (with a size cut at 10 μ m, PM _10 , or without any size cut) at eight observatories representing all Arctic sectors. Our holistic observational approach includes the Russian Arctic, a significant emission source area with less dedicated aerosol monitoring, and extends beyond the more traditionally studied summer period and black carbon/sulfate or fine-mode pollutants. The major airborne Arctic PM components in terms of dry mass are sea salt, secondary (non-sea-salt, nss) sulfate, and organic aerosol (OA), with minor contributions from elemental carbon (EC) and ammonium. We observe substantial spatiotemporal variability in component ratios, such as EC/OA, ammonium/nss-sulfate and OA/nss-sulfate, and fractional contributions to PM. When combined with component-specific back-trajectory analysis to identify marine or terrestrial origins, as well as the companion study by Moschos et al 2022 Nat. Geosci. focusing on OA, the composition analysis provides policy-guiding observational insights into sector-based differences in natural and anthropogenic Arctic aerosol sources. In this regard, we first reveal major source regions of inner-Arctic sea salt, biogenic sulfate, and natural organics, and highlight an underappreciated wintertime source of primary carbonaceous aerosols (EC and OA) in West Siberia, potentially associated with the oil and gas sector. The presented dataset can assist in reducing uncertainties in modelling pan-Arctic aerosol-climate interactions, as the major contributors to yearly aerosol mass can be constrained. These models can then be used to predict the future evolution of individual inner-Arctic atmospheric PM components in light of current and emerging pollution mitigation measures and improved region-specific emission inventories.

This is a response to the questions asked by Franco Passalacqua and Federico Pianzola as a follow-up of the 2013 ENN conference. The discussions that originated at the conference were rich and thought-provoking and so the editors of this special section of «Enthymema» decided to continue the dialogue about the state of the art and the future of narratology.

The aim of this research is an improvement of plant seedling recognition by two new approaches of shape feature generation based on plant silhouettes. Experiments show that the proposed feature sets possess value in plant recognition when compared with other feature sets. Both methods approximate a distance distribution of an object, either by resampling or by approximation of the distribution with a high degree Legendre polynomial. In the latter case, the polynomial coefficients constitute a feature set. The methods have been tested through a discrimination process where two similar plant species are to be distinguished into their respective classes. The used performance assessment is based on the classification accuracy of 4 different classifiers (a k-Nearest Neighbor, Naive-Bayes, Linear Support Vector Machine, Nonlinear Support Vector Machine). Another set of 21 well-known shape features described in the literature is used for comparison. The used data consisted of 139 samples of cornflower (Centaura cyanus L.) and 63 samples of nightshade (Solanum nigrum L.). The highest discrimination accuracy was achieved with the Legendre Polynomial feature set and amounted to 97.5%. This feature set consisted of 10 numerical values. Another feature set consisting of 21 common features achieved an accuracy of 92.5%. The results suggest that the Legendre Polynomial feature set can compete with or outperform the commonly used feature sets.

In this paper we investigate the connections between population development, socio-economic status and the sense of belonging, in the understanding of social life in places. The article is based on a mixed-method study that includes register-based demographic data on inhabitants in the municipality of Aalborg in Denmark, survey data, and findings from fifty qualitative ethnographic interviews. We argue that local belonging is important to people, although increasingly complex and varied across local neighbourhoods. The conceptualization of the relations between demographic change, neighbourhood development and belonging is influenced by the Human Ecology (Park & Burgess 1925) that offers useful but also premature theoretical contributions in this field. Thus we argue that this perspective need to be expanded in order to pay attention to the varied meanings ascribed to place and discuss the possibility of mapping out zones of belonging in the contemporary society.

Observations from a large number of seabird line-transect surveys conducted in Faroese waters are used to derive some general conclusions regarding the distribution of harbour porpoises (Phocoena phocoena) in the region using estimates of encounter rates (no./km-1) in different meso-scale habitats around the Faroes during the breeding season (May-September). Based on a sub-set of the data collected during calm conditions (sea states below Beaufort 3) we analysed the distribution of harbour porpoises in relation to 5 potentially important physical parameters: water depth, distance to shore, slope of the ocean floor, distance to tidal front and Beaufort sea state. These parameters were determined from data collected during the surveys, the literature as well as from the new bathymetry established for the Faroese shelf. In order to link the differently scaled physical parameters with the encounter rates and sea states recorded during the surveys we used a suite of geo-statistical and raster-based GIS techniques based on a uniform grid resolution of 1 km in UTM zone 29 N projection. After removing parameters with insignificant effects a model of main effects was produced with sea state and distance to the tidal front having a significant negative effect on the rate of encountering harbour porpoises during both sets of cruises analysed (August 1997 and other surveys). During both sets of cruises the distance to the tidal front had a larger effect on the distribution of the animals than sea state. The strong relationship between harbour porpoise distribution and the average position of the tidal front around the Faroes strongly suggests that the species concentrates near the quasi-stationary circular shelf front separating mixed from stratified waters around the Faroes. However, the importance of shelf fronts for the distribution of harbour porpoises needs to be studied in detail in order to establish the proportionof the populations associated with these structures.

Overordnet set ved vi meget om, hvordan Udkantsdanmark udvikler sig. De unge rejser imod de større byer, ældrebyrden vokser, antallet af offentlige institutioner er lavt, og der er dårlige beskæftigelsesforhold. Derimod ved vi langt mindre om, hvordan udviklingen forholder sig mere lokalt eller på mindre skala i Udkantsdanmark. Nærværende artikel vil diskutere behovet for at se Udkantsdanmark med mere nuancerede briller. Briller, hvor man ikke anskuer Udkantsdanmark som en samlet geografiske enhed, men snarere som en samling af mange mindre områder, der hver især har sin egen udvikling og historie at fortælle.

The stricter legislation within the European Union for the regulation of herbicides that are prone to leaching causes a greater economic burden on the agricultural industry through taxation. Owing to the increased economic burden, research in reducing herbicide usage has been prompted. High-resolution images from digital cameras support the studying of plant characteristics. These images can also be utilized to analyze shape and texture characteristics for weed identification. Instead of detecting weed patches, weed density can be estimated at a sub-patch level, through which even the identification of a single plant is possible. The aim of this study is to adapt the monocot and dicot coverage ratio vision (MoDiCoVi) algorithm to estimate dicotyledon leaf cover, perform grid spraying in real time, and present initial results in terms of potential herbicide savings in maize. The authors designed and executed an automated, large-scale field trial supported by the Armadillo autonomous tool carrier robot. The field trial consisted of 299 maize plots. Half of the plots (parcels) were planned with additional seeded weeds; the other half were planned with naturally occurring weeds. The in-situ evaluation showed that, compared to conventional broadcast spraying, the proposed method can reduce herbicide usage by 65% without measurable loss in biological effect.

In a "wasp-waist" ecosystem, an intermediate trophic level is expected to control the abundance of predators through a bottom-up interaction and the abundance of prey through a top-down interaction. Previous studies suggest that the North Sea is mainly governed by bottom-up interactions driven by climate perturbations. However, few studies have investigated the importance of the intermediate trophic level occupied by small pelagic fishes.We investigated the numeric interactions among 10 species of seabirds, two species of pelagic fish and four groups of zooplankton in the North Sea using decadal-scale databases. Linear models were used to relate the time series of zooplankton and seabirds to the time series of pelagic fish. Seabirds were positively related to herring (Clupea harengus), suggesting a bottom-up interaction. Two groups of zooplankton; Calanus helgolandicus and krill were negatively related to sprat (Sprattus sprattus) and herring respectively, suggesting top-down interactions. In addition, we found positive relationships among the zooplankton groups. Para/pseudocalanus was positively related to C. helgolandicus and C. finmarchicus was positively related to krill.Our results indicate that herring was important in regulating the abundance of seabirds through a bottom-up interaction and that herring and sprat were important in regulating zooplankton through top-down interactions. We suggest that the positive relationships among zooplankton groups were due to selective foraging and switching in the two clupeid fishes. Our results suggest that "wasp-waist" interactions might be more important in the North Sea than previously anticipated. Fluctuations in the populations of pelagic fish due to harvesting and depletion of their predators might accordingly have profound consequences for ecosystem dynamics through trophic cascades.

Cooperative hunting involves individual predators relating in time and space to each other's actions to more efficiently track down and catch prey. The evolution of advanced cognitive abilities and sociality in animals are strongly associated with cooperative hunting abilities as has been shown in lions, chimpanzees, and dolphins. Much less is known about cooperative hunting in seemingly unsocial animals, such as the harbour porpoise (Phocoena phocoena (Linnaeus, 1758)). Using drones, we were able to record 159 hunting sequences of porpoises, out of which 95 sequences involved more than one porpoise. To better understand if the harbour porpoises were individually attracted by the fish school or formed an organized hunting strategy, the behaviour of each individual porpoise in relation to the targeted fish school was analysed. The results indicate role specialization, which is considered the most sophisticated form of collaborative hunting and only rarely seen in animals. Our study challenges previous knowledge about harbour porpoises and opens up for the possibility of other seemingly non-social species employing sophisticated collaborative hunting methods. Key words: behaviour, collaboration, communication, drone, harbour porpoise, Phocoena phocoena. Dans la chasse coopérative, les actions de différents prédateurs sont reliées dans le temps et l'espace pour permettre la poursuite et la capture plus efficaces de proies. Le développement de capacités cognitives avancées et de la socialité chez les animaux est fortement associé aux capacités de chasse coopérative, comme cela a été démontré chez les lions, les chimpanzés et les dauphins. Les connaissances sur la chasse coopérative chez des animaux en apparence non sociaux, comme les marsouins communs (Phocoena phocoena (Linnaeus, 1758)) sont beaucoup plus limitées. À l'aide de drones, nous avons pu enregistrer 159 séquences de chasse de marsouins, à 95 desquelles plus d'un marsouin ont participé. Pour mieux comprendre si les marsouins communs étaient attirés individuellement par le banc de poissons ou ont employé une stratégie de chasse organisée, le comportement de chaque marsouin par rapport au banc de poissons ciblé a été analysé. Les résultats indiquent une spécialisation des rôles, qui est considérée comme la forme de chasse coopérative la plus complexe et n'est que rarement observée chez les animaux. Notre étude remet en question les connaissances passées sur les marsouins communs et laisse entrevoir la possibilité que d'autres espèces en apparence non sociales emploient des méthodes de chasse coopérative complexes. [Traduit par la Rédaction] Mots-clés : comportement, coopération, communication, drone, marsouin commun, Phocoena phocoena., Introduction Cooperative hunting involves individual predators relating in time and space to each other's actions to more efficiently track down and catch prey (Bailey et al. 2013). We can refer [...]