ALBERT

Beschreibung: Due to some harmful effects on humans and the environment, particulate matter (PM) has recently become among the most studied atmospheric pollutants. Given the growing sensitivity to the problem and, since production and accumulation phenomena involving both primary and secondary P M 10 fractions are complex and non-linear, environmental authorities need tools to assess their plans designed to improve the air quality as requested from environmental laws. Multi-criteria decision analysis (MCDA) can be applied to support decision makers, by processing quantitative opinions provided by pools of experts, especially when different views on social aspects should be considered. The results obtained through this approach, however, can be highly dependent on the subjectivity of experts. To partially overcome these challenges, this paper suggests a two-step methodology in which an MCDA is fed with the solution of a multi-objective analysis (MOA). The methodology has been applied to a test case in northern Italy and the results show that this approach is a viable solution for the inclusion of subjective criteria in decision making, while reducing the impact of uncertain expert opinions for data that can be computed through the MOA.

Beschreibung: Both the global circulation model (GCM) and regional climate model (RCM) simulations suffer from model biases that eventually result in significant errors in regional forecasts. This model bias issue is addressed using the bias correction approach. This study examines the influence of bias correction on the performance of downscaling simulations of the East Asian winter climate using the Global/Regional Integrated Model system (GRIMs). To assess the bias correction approach, we conducted three sets of simulations for 25 winters (December to February) from 1982 to 2006 over East Asia. The GRIMs were forced by the (1) National Centers for Environmental Prediction (NCEP) Department of Energy (DOE) reanalysis data, (2) original NCEP Climate Forecast System (CFS) data, and (3) bias-corrected CFS data. The GCM climatological means were adjusted based on the NCEP–DOE reanalysis data. The bias correction method was applied to zonal and meridional wind, temperature, geopotential height, specific humidity, and sea surface temperature of the CFS data. The GCM-driven experiments with/without bias correction were compared with the reanalysis-driven simulation. The results of this comparison suggest that the application of bias correction improves the downscaled climate in terms of the climatological mean, inter-annual variability, and extreme events owing to the elimination of errors in large-scale circulations. The effect of bias correction on the simulated extreme event is not as significant as those on the climatological mean and inter-annual variability, but the increased skill appears to be a clue for potential use for predicting extreme events.

Beschreibung: The present paper deals with a field experiments on evaporite rock samples and groundwater investigations in the Quinis test site, a hamlet of the Enemonzo municipality in NE Italy, were sinkholes occurred in the past and are still occurring causing severe damage to the existing infrastructures. The area is characterised by a Carnian evaporitic bedrock made of gypsum and anhydrite mantled by alluvial and colluvial deposits. In order to evaluate the loss of weight and volume of the subcropping evaporites as responsible for sinkholes, a field-experiment was carried out. Inside seven piezometers, at different depths, evaporitic rock samples were exposed to the naturally occurring variable climatic conditions such as degree of humidity, different air flow and hydrodynamic. The rock samples were installed at the beginning of April 2017 in the dry sections of piezometric tubes, in the vadose zone and in the phreatic zone. Data related to water level fluctuations were recorded by using data-logger devices and highlight significant changes in the water table. After 13 months of data recording (May 2018), rock samples were removed, reweighted and the volume loss measured. In addition, water from piezometer-experiment, representative of the groundwater circulation, were collected at different depths. The obtained results indicate that rock sample reduction is dependent on the hydrological regime and water chemistry and not on the number of days during which the samples remained submersed. In particular, the water geochemistry highlights the possible role in gypsum/anhydrite dissolution due to NaCl water admixing in a complex scenario. In additional, the geochemical data highlight the occurrence of some potentially toxic elements (As, Fe, Mn) at concentrations of concern in some water. This approach represents a novel contribution in the study of karst hazard in evaporites adding a tile to the knowledge of the fast evolutionary processes which cause sinkhole formation.

Beschreibung: In order to provide a good theoretical guidance for the development and utilization of weathered phosphorite resources, we investigated the geochemical and mineralogical characteristics of primary and weathered phosphorites. The analysis of trace elements showed that the primary ore has hydrothermal sedimentation effect in the later stage, the weathered ore has obvious residual enrichment and the phosphate ore belongs to clastic lithologic phosphate rock. In addition, through leaching test method, it was shown that rare earth elements are present in fluorapatite in the form of isomorphic substitution, and the proportion of rare earth elements adsorbed on clay and other minerals was likely to be between 2% and 3%. The light rare earth elements are relatively enriched in both primary and weathered phosphorite, and Ce and Eu have obvious negative anomalies. The primary phosphorite is a dolomitic phosphorite containing rare earth elements, which are naturally enriched by weathering, and its weathered ore has obvious residual enrichment, while the deposit was characterized by normal marine sedimentation and hydrothermal action.

Beschreibung: High daily temperatures in the Mediterranean and Europe have been documented in observation and modeling studies. Long-term temperature data, from 1988 to 2017, from a suburban station and an urban station in Nicosia, Cyprus have been analyzed, and the diurnal temperature range (DTR) trend was investigated. The seasonal Mann–Kendall test revealed a decreasing DTR trend of −0.24 °C/decade at the urban station and −0.36 °C/decade at the suburban station, which were attributed to an increase in the daily minimum temperature. Variations in precipitation, longwave radiation, ultraviolet-A (UVA), ultraviolet-B (UVB), cloud cover, water vapor, and urbanization were used to assess their possible relationship with regional DTR. The clustering of daytime and night-time data showed a strong relationship between the DTR and observed cloud cover, net longwave radiation, and precipitation. Clouds associated with smaller shortwave and net longwave radiation reduce the DTR by decreasing the surface solar radiation, while atmospheric absolute humidity denotes an increased daytime surface evaporative cooling and higher absorption of the short and longwave radiation. The intra-cluster variation could be reduced, and the inter-cluster variance increased by the addition of other meteorological parameters and anthropogenic sources that affect DTR in order to develop a quantitative basis for assessing DTR variations.

Beschreibung: Greenhouse gases emitted from soil play a crucial role in the atmospheric environment and global climate change. The theory and technique of detecting stable isotopes in the atmosphere has been widely used to an investigate greenhouse gases from soil. In this paper, we review the current literature on greenhouse gases emitted from soil, including carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O). We attempt to synthesize recent advances in the theory and application of stable isotopes in greenhouse gases from soil and discuss future research needs and directions.

Beschreibung: Microbes can mediate the precipitation of primary dolomite under surface conditions. Meanwhile, primary dolomite mediated by microbes often contains more Fe2+ than standard dolomite in modern microbial culture experiments. Ferroan dolomite and ankerite have been regarded as secondary products. This paper reviews the process and possible mechanisms of microbial mediated precipitation of primary ferroan dolomite and/or ankerite. In the microbial geochemical Fe cycle, many dissimilatory iron-reducing bacteria (DIRB), sulfate-reducing bacteria (SRB), and methanogens can reduce Fe3+ to Fe2+, while SRB and methanogens can also promote the precipitation of primary dolomite. There are an oxygen respiration zone (ORZ), an iron reduction zone (IRZ), a sulfate reduction zone (SRZ), and a methanogenesis zone (MZ) from top to bottom in the muddy sediment diagenesis zone. DIRB in IRZ provide the lower section with Fe2+, which composes many enzymes and proteins to participate in metabolic processes of SRB and methanogens. Lastly, heterogeneous nucleation of ferroan dolomite on extracellular polymeric substances (EPS) and cell surfaces is mediated by SRB and methanogens. Exploring the origin of microbial ferroan dolomite may help to solve the “dolomite problem”.

Beschreibung: Pyrometallurgical processing of ore from the Zeehan mineral field was performed intermittently between 1896 and 1948, primarily recovering Pb, Ag and Cu. While Zn recovery was attempted at the time, it was unsuccessful using the available technology. Consequently, Zn reported to the slag during the smelting process. Today, the former smelter site consists of two large slag piles (North and South). Using a range of techniques (including X-ray diffractometry, scanning electron microscopy, laser ablation inductively coupled plasma mass spectrometry, and static testing) the geometallurgical and geo-environmental properties of these slag materials (n = 280) were determined. The South and North piles contain on average 15% and 11% Zn, respectively. A range of complex mineral phases were identified, and are dominated by glass, silicates (i.e., monticellite–kirschsteinite and hardystonite), oxides (gahnite and hercynite) and minor sulfides (sphalerite and wurtzite). Microtextural examinations defined nine mineral phases (Glass A, Silicates A to D, Oxides A and B, Sulfides A and B). Zn was concentrated in Sulfide A (26%), Glass A (24%) and the Silicates (43%), while Pb was concentrated in Oxide B (76%), with Sulfide B host to the highest Ag (45%) and Cu (65%). Considering this, recovery of Zn using conventional hydrometallurgical processes (i.e., sulfuric acid leaching) is suitable, however the application of unconventional biohydrometallurgical techniques could be explored, as well re-smelting. These slag materials are classified geo-environmentally as potentially acid forming, with leachate concentrations of Zn, Pb consistently above ANZECC (2000) aquatic ecosystem 80% protection guideline values, and, for the majority of samples, exceedances of Cu, Ni and Cd were also measured. Considering these findings, reprocessing of these historic slags for Zn extraction may provide an economically feasible management option for rehabilitating this historical site.

Beschreibung: New findings of silicate-melt inclusions in two alluvial diamonds (from the Kholomolokh placer, northeastern Siberian Platform) are reported. Both diamonds exhibit a high degree of N aggregation state (60–70% B) suggesting their long residence in the mantle. Raman spectral analysis revealed that the composite inclusions consist of clinopyroxene and silicate glass. Hopper crystals of clinopyroxene were observed using scanning electron microscopy and energy-dispersive spectroscopic analyses; these are different in composition from the omphacite inclusions that co-exist in the same diamonds. The glasses in these inclusions contain relatively high SiO2, Al2O3, Na2O and, K2O. These composite inclusions are primary melt that partially crystallised at the cooling stage. Hopper crystals of clinopyroxene imply rapid cooling rates, likely related to the uplift of crystals in the kimberlite melt. The reconstructed composition of such primary melts suggests that they were formed as the product of metasomatised mantle. One of the most likely source of melts/fluids metasomatising the mantle could be a subducted slab.

Beschreibung: Flows originating from alpine dominated cold region watersheds typically experience extended winter low flows followed by spring snowmelt and summer rainfall driven high flows. In a warmer climate, there will be a temperature-induced shift in precipitation from snowfall towards rain along with changes in precipitation intensity and snowmelt timing, resulting in alterations in the frequency and magnitude of peak flow events. This study examines the potential future changes in the frequency and severity of peak flow events in the Athabasca River watershed in Alberta, Canada. The analysis is based on simulated flow data by the variable infiltration capacity (VIC) hydrologic model driven by statistically downscaled climate change scenarios from the latest coupled model inter-comparison project (CMIP5). The hydrological model projections show an overall increase in mean annual streamflow in the watershed and a corresponding shift in the freshet timing to an earlier period. The river flow is projected to experience increases during the winter and spring seasons and decreases during the summer and early fall seasons, with an overall projected increase in peak flow, especially for low frequency events. Both stationary and non-stationary methods of peak flow analysis, performed at multiple points along the Athabasca River, show that projected changes in the 100-year peak flow event for the high emissions scenario by the 2080s range between 4% and 33% depending on the driving climate models and the statistical method of analysis. A closer examination of the results also reveals that the sensitivity of projected changes in peak flows to the statistical method of frequency analysis is relatively small compared to that resulting from inter-climate model variability.

Beschreibung: The nature of upper mantle is important to understand the evolution of the South China Sea (SCS); thus, we need better constrains on its mantle heterogeneity. Magma water concentration is a good indicator, but few data have been reported. However, the rarity of glass and melt inclusions and the special genesis for phenocrysts in SCS basalts present challenges to analyzing magmatic water content. Therefore, it is possible to estimate the water variations through the characteristics of partial melting and magma crystallization. We evaluated variations in Fe depletion, degree of melt fractions, and mantle source composition along the fossil spreading ridge (FSR) using SCS basalt data from published papers. We found that lava from the FSR 116.2° E, FSR 117.7° E, and non-FSR regions can be considered normal lava with normal water content; in contrast, lava from the FSR 117° E-carbonatite and 114.9–115.0° E basalts have higher water content and show evidence of strong Fe depletion during the fractional crystallization after elimination of the effects of plagioclase oversaturation. The enriched water in the 117° E-carbonatite basalts is contained in carbonated silicate melts, and that in the 114.9–115.0° E basalts results from mantle contamination with the lower continental crust. The lava from the 117° E-normal basalt has much lower water content because of the lesser influence of the Hainan plume. Therefore, there must be a mantle source compositional transition area between the southwestern and eastern sub-basins of the SCS, which have different mantle evolution histories. The mantle in the west is more affected by contamination with continental materials, while that in the east is more affected by the Hainan mantle plume.

Beschreibung: This work intends to embed the estimation of the joint roughness coefficient (JRC) in the framework of random fields. The random field method is a probabilistic approach which involves modeling of the spatial variability of the pertinent physical quantities as a fundamental part of the (assumed) underlying probabilistic structure. Although this method is one of higher complexity in regard of the presumed background knowledge, it encodes naturally subtler information about the rock surface roughness. It is noted that, the proposed random field approach considers automatically the scale of the problem (no correction factor is needed), whilst the JRC estimates appear to be more stable (compared to those derived from Z2 or SF) in the sense that images of the same profile but of different quality give similar results for its roughness. The present work could also be useful in advanced probabilistic rock slope stability analysis based on random fields. In such a case, the required spatial correlation length θ can be obtained by the proposed θ = 145.5 σ/JRC relationship (σ = variance of the profile). The JRC can be obtained through tilt tests, push or pull tests, or matching roughness profiles, whilst σ can be obtained from inspection of the digitized profile.

Beschreibung: The large-scale Maoping W–Sn deposit in the Gannan metallogenic belt of the eastern Nanling Range, South China, spatially associated with the Maoping granite pluton, hosts total ore reserves of 103,000 t WO3 and 50,000 t Sn. Two different types of mineralization developed in this deposit: Upper quartz vein-type mineralization, mostly within the Cambrian metamorphosed sandstone and slate, and underneath greisen-type mineralization within the Maoping granite. Cassiterites from both types of mineralization coexist with wolframite. Here we report for the first time in situ U–Pb data on cassiterite and zircon of the Maoping deposit obtained by LA-ICP-MS. Cassiterite from quartz vein and greisen yielded weighted average 206Pb/238U ages of 156.8 ± 1.5 Ma and 156.9 ± 1.4 Ma, respectively, which indicates that the two types of mineralization formed roughly at the same time. In addition, the two mineralization ages are consistent with the emplacement age of the Maoping granite (159.0 ± 1.5 Ma) within error, suggesting a close temporal and genetic link between W–Sn mineralization and granitic magmatism. The two types of mineralization formed at the same magmatic-hydrothermal event. Cassiterite from both types of mineralization shows high Fe, Ta, and Zr contents with a low Zr/Hf ratio, suggesting that the ore-forming fluid should be derived from the highly differentiated Maoping granite pluton. Cassiterite in greisen has higher contents of Nb and Ta but a lower concentration of Ti compared with that in quartz vein, indicating that the formation temperature of greisen-type mineralization is little higher than that of quartz-vein-type mineralization.

Beschreibung: The Postmasburg Manganese Field (PMF), Northern Cape Province, South Africa, once represented one of the largest sources of manganese ore worldwide. Two belts of manganese ore deposits have been distinguished in the PMF, namely the Western Belt of ferruginous manganese ores and the Eastern Belt of siliceous manganese ores. Prevailing models of ore formation in these two belts invoke karstification of manganese-rich dolomites and residual accumulation of manganese wad which later underwent diagenetic and low-grade metamorphic processes. For the most part, the role of hydrothermal processes and metasomatic alteration towards ore formation has not been adequately discussed. Here we report an abundance of common and some rare Al-, Na-, K- and Ba-bearing minerals, particularly aegirine, albite, microcline, banalsite, sérandite-pectolite, paragonite and natrolite in Mn ores of the PMF, indicative of hydrothermal influence. Enrichments in Na, K and/or Ba in the ores are generally on a percentage level for most samples analysed through bulk-rock techniques. The presence of As-rich tokyoite also suggests the presence of As and V in the hydrothermal fluid. The fluid was likely oxidized and alkaline in nature, akin to a mature basinal brine. Various replacement textures, particularly of Na- and K- rich minerals by Ba-bearing phases, suggest sequential deposition of gangue as well as ore-minerals from the hydrothermal fluid, with Ba phases being deposited at a later stage. The stratigraphic variability of the studied ores and their deviation from the strict classification of ferruginous and siliceous ores in the literature, suggests that a re-evaluation of genetic models is warranted. New Ar-Ar ages for K-feldspars suggest a late Neoproterozoic timing for hydrothermal activity. This corroborates previous geochronological evidence for regional hydrothermal activity that affected Mn ores at the PMF but also, possibly, the high-grade Mn ores of the Kalahari Manganese Field to the north. A revised, all-encompassing model for the development of the manganese deposits of the PMF is then proposed, whereby the source of metals is attributed to underlying carbonate rocks beyond the Reivilo Formation of the Campbellrand Subgroup. The main process by which metals are primarily accumulated is attributed to karstification of the dolomitic substrate. The overlying Asbestos Hills Subgroup banded iron formation (BIF) is suggested as a potential source of alkali metals, which also provides a mechanism for leaching of these BIFs to form high-grade residual iron ore deposits.

Beschreibung: Mixed cyanobacteria-dominated biofilms, enriched from a tributary of the Mérantaise (France) were used to conduct laboratory experiments in order to understand the relationship between the morphology of carbonate precipitates and the biological activity (e.g., cyanobacterial exopolymeric substances (EPS) production, photosynthetic pH increases). DNA sequencing data showed that the enriched biofilm was composed predominantly of two types of filamentous cyanobacteria that belonged to the Oscillatoriaceae and Phormidiaceae families, respectively. Microscopic analysis also indicated the presence of some coccoid cyanobacteria resembling Gloeocapsa. Analysis of carbonate precipitates in experimental biofilms showed three main morphologies: micro-peloids with different shapes of mesocrystals associated with Oscillatoriaceae filaments and theirs EPS, lamellae of carbonate formed directly on Phormidiaceae filaments, and rhombic sparite crystals wrapped in EPS. All crystals were identified by FT-IR spectroscopy as calcite. Similar structures as those that formed in laboratory conditions were observed in the microbial-tufa deposits collected in the stream. Microscopic and spectroscopic analysis of laboratory and natural samples indicated a close proximity of the cyanobacterial EPS and precipitated carbonates in both. Based on the laboratory experiments, we conclude that the microbial tufa in the stream is in an early stage of formation.

Beschreibung: We present a joint 2D inversion approach for magnetotelluric (MT) and gravity data with elastic-net regularization and cross-gradient constraints. We describe the main features of the approach and verify the inversion results against a synthetic model. The results indicate that the best fit solution using the L2 is overly smooth, while the best fit solution for the L1 norm is too sparse. However, the elastic-net regularization method, a convex combination term of L2 norm and L1 norm, can not only enforce the stability to preserve local smoothness, but can also enforce the sparsity to preserve sharp boundaries. Cross-gradient constraints lead to models with close structural resemblance and improve the estimates of the resistivity and density of the synthetic dataset. We apply the novel approach to field datasets from a copper mining area in the northeast of China. Our results show that the method can generate much more detail and a sharper boundary as well as better depth resolution. Relative to the existing solution, the large area divergence phenomenon under the anomalous bodies is eliminated, and the fine anomalous bodies boundary appeared in the smooth region. This method can provide important technical support for detecting deep concealed deposits.

Beschreibung: Bangladesh remains one of the most vulnerable countries in the world to the effects of climate change. Given the reliance of a large segment of the population on the agricultural sector for both their livelihoods as well as national food security, climate change adaptation in the agricultural sector is crucial for continued national food security and economic growth. Using household data from lowland rice farmers of selected haor areas in Sylhet, the current work presents an analysis of the determinants behind the implementation of different climate change adaptation strategies by lowland rice farmers. The first objective of this study was to explore the extent of awareness of climate change within this population as well as the type of opinions held by lowland rice farmers with respect to climate change. To serve this purpose, a severity index (SI) was developed and subsequently employed to evaluate the perceptions and attitudes of 378 farmers with respect to climate change vulnerability. Respondents were interviewed with respect to climate change related circumstances they faced in their daily lives. Attained SI index values ranged from 69.18% to 93.52%. The SI for the perception “Climate change affects rice production” was measured as 93.52%. Using data collected from the same 378 farmers, a logistic regression was carried out to investigate the impact of socio-economic and institutional factors on adaptation. The results show that credit from non-government organizations is highly statistically significant for adaptation, and that rural market structure also has a positive effect on adaptation. Among the studied factors, credit from non-governmental organizations (NGOs) was found to be the most important factor for adaptation. The results of this work further indicate that marginal farmers would benefit from government (GoB) funded seasonal training activities that cover pertinent information regarding adaptation after flash floods. Additionally, the authors of this piece recommend timely issuance of government-assisted credit during early flash floods to afflicted farmers, as such an initiative can aid farmers in adapting different strategies to mitigate losses and enhance their productivity as well as livelihood.

Beschreibung: The vertical profiles and trends of temperature and humidity at the South Pole up to 10 km above mean sea level (amsl) were investigated by using radiosonde data collected from March 2005 to February 2018. During an average year between 2005 and 2018, the highest (lowest) temperature in the lower troposphere was approximately −25 °C (−60 °C) in December (July) at a height of about 500 m above the surface (at the surface). A temperature inversion layer above the surface was found during the whole year but was weaker during the summer, while the inversion layers at the tropopause (about 8 km amsl) mostly disappeared during spring and winter. General warming trends were found at all heights and months, but in a few heights and months cooling trends still occurred (e.g., in September below 7 km amsl). Nevertheless, seasonal and yearly averaged temperatures all presented warming trends: 1.1, 1.3, 0.6, 1.5 and 1.1 °C/decade at the surface, and 0.7, 1.0, 0.3, 0.3 and 0.6 °C/decade for the layer average from the surface to 10 km amsl, for spring, summer, autumn, winter, and yearly average, respectively. Most of the water vapor was confined in the lowermost 3 km of the atmosphere with a maximum of 0.35 g kg−1 in December at a 200 m height above surface, and the specific humidity had the similar characteristic of annual cycle and inversion layers as the temperature. At heights below 5 km amsl, increasing trends of specific humidity larger than 0.02 g kg−1/decade occurred during summer months, including the late spring and early autumn, and the annual mean showed an increasing trend of about 0.01–0.02 g kg−1/decade. Meanwhile, above 5 km amsl, the trends became small and generally less than 0.02 g kg−1/decade in all the months, and beyond 7 km amsl the specific humidity remained almost invariant due to its small moisture content as compared with lower levels. From the surface to 10 km amsl, the specific humidity averaged trends of 0.0062, 0.019, 0.0013, 0.002 and 0.007 g kg−1/decade for spring, summer, autumn, winter and yearly average, respectively.

Beschreibung: In several studies conducted recently, it was shown that equations pertinent to the electric and magnetic fields produced by electrical charges in motion can be used to calculate the electromagnetic fields produced by current pulses propagating along linearly restricted paths. An example includes the case of current pulses propagating along conductors and conducting channels such as lightning. In this paper, it is shown how the technique can be applied to estimate the electromagnetic fields generated by current and charge distributions moving in arbitrary directions in space. The analysis shows that, depending on the way the problem is formulated using the field equations pertinent to accelerating charges, one procedure leads to the generalized dipole equations, which are independent of the velocity of propagation of the current, and the other procedure leads to a set of equations that depend on the velocity. Using the well-tested transmission line model of lightning return strokes as an example, it is shown that both sets of field equations give rise to the same total electromagnetic field.

Beschreibung: Urban-induced thermal stress can threaten human health, especially during heat waves (HWs). The growth of cities further exacerbates this effect. Here, weather research and forecasting (WRF) with an urban canopy model (UCM) is used to assess the effects of megacities and their growth on the thermal regime of proximal cities during heat waves. Analysis of the heat fluxes shows that advection impacts cities downwind. Results indicate that as urban areas change size (50%–100% and 100–150% of their current size), the local 2 m temperature increases by 2.7 and 1.7 °C, and the 2 m specific humidity decreases by 2.1 and 1.4 g kg−1, respectively. A small city downwind is impacted with a 0.3–0.4 °C increase in 2 m temperature. Green roof is a potential mitigation strategy for these regions (i.e., beyond the megacity). With 50% green roofs in an urban area, a 0.5 °C decrease in 2 m temperature and 0.6 g kg−1 increase in specific humidity is simulated. Urbanization upwind of a megacity will contribute to regional climate change.

Beschreibung: Drought and extreme temperatures forecasting is important for water management and the prevention of health risks, especially in a period of observed climatic change. A large precipitation deficit together with increased evapotranspiration rates in the preceding days contribute to exceptionally high temperature anomalies in the summer above the average local maximum temperature for each month. Using a retrospective approach, this study investigated droughts and extreme temperatures in the greater area of Nicosia, Cyprus and suggests a different approach in determining the lag period of summer temperature anomalies and precipitation. In addition, dry conditions defined with the use of the Standardized Precipitation-Evapotranspiration Index (SPEI) were associated with positive temperature anomalies at a percentage up to 33.7%. The compound effect of precipitation levels and evapotranspiration rates of the preceding days for the period 1988–2017 to summer temperature anomalies was demonstrated with significantly statistical R squared values up to 0.57. Furthermore, the cooling effect of precipitation was higher and prolonged longer in rural and suburban than urban areas, a fact that is directly related to the evaporation potential of the area in concern. Our work demonstrates the compound effect of precipitation levels and evapotranspiration rates of the preceding days to summer temperature anomalies.

Beschreibung: The potential costs of road traffic accidents (RTAs) to society are immense. Yet, no study has attempted to examine the impact of climate change on RTAs in Saudi Arabia, though RTA-leading deaths are very high, and the occurrence of climatic events is very frequent. Therefore, this study aims to assess the impact of climate change on RTAs in Saudi Arabia and to recommend some climate change mitigation and adaptation policies to make roads safe for all. This study employed annual data from 13 regions of Saudi Arabia, from 2003 to 2013. The data were analyzed on the basis of panel regression models—fixed effect, random effect, and the pooled ordinary least square. The findings show that temperature, rainfall, sandstorms, and number of vehicles were statistically and significantly responsible for RTAs in Saudi Arabia in the study period. This study also found that RTAs both inside and outside cities significantly caused injuries, but only RTAs inside cities significantly caused death. Furthermore, the death from RTAs injuries was found to be statistically significant only for motor vehicle accidents. The findings will assist policymakers in taking the right courses of action to mitigate the negative impacts of climate change through understanding climate influence on RTAs.

Beschreibung: Removal of calcium and magnesium ions through biomineralization induced by bacteria has been proven to be an effective and environmentally friendly method to improve water quality, but the process and mechanism are far from fully understood. In this study, a newly isolated probiotic Bacillus licheniformis SRB2 (GenBank: KM884945.1) was used to induce the bio-precipitation of calcium and magnesium at various Mg/Ca molar ratios (0, 6, 8, 10, and 12) in medium with 30 g L−1 sodium chloride. Due to the increasing pH and HCO3− and CO32− concentrations caused by NH3 and carbonic anhydrase, about 98% Ca2+ and 50% Mg2+ were precipitated in 12 days. The pathways of bio-precipitation include extracellular and intracellular processes. Biominerals with more negative δ13C values (−16‰ to −18‰) were formed including calcite, vaterite, monohydrocalcite, and nesquehonite with preferred orientation. The nucleation on extracellular polymeric substances was controlled by the negatively charged amino acids and organic functional groups. The intracellular amorphous inclusions containing calcium and magnesium also contributed to the bio-precipitation. This study reveals the process and mechanism of microbial desalination for the removal of calcium and magnesium, and provides some references to explain the formation of the nesquehonite and other carbonate minerals in a natural and ancient earth surface environment.

Beschreibung: Runoff in snowy alpine regions is sensitive to climate change in the context of global warming. Exploring the impact of climate change on the runoff in these regions is critical to understand the dynamics of the water cycle and for the improvement of water resources management. In this study, we analyzed the long-term variations in annual runoff in the headwaters region of the Yellow River (HRYR) (a typical snowy mountain region) during the period of 1956–2012. The Soil and Water Assessment Tool (SWAT) with different elevation bands was employed to assess the performance of monthly runoff simulations, and then to evaluate the impacts of climate change on runoff. The results show that the observed runoff for the hydrological stations at lower relative elevations (i.e., Maqu and Tangnaihai stations) had a downward trend, with rates of 1.91 and 1.55 mm/10 years, while a slight upward trend with a rate of 0.26 mm/10 years was observed for the hydrological station at higher elevation (i.e., Huangheyan station). We also found that the inclusion of five elevation bands could lead to more accurate runoff estimates as compared to simulation without elevation bands at monthly time steps. In addition, the dominant cause of the runoff decline across the whole HRYR was precipitation (which explained 64.2% of the decrease), rather than temperature (25.93%).

Beschreibung: In order to conduct real-time quantitative monitoring of dust storms, Ka-band millimeter wave radar (MMWR) was utilized for the consecutive detection of dust storms over the Taklimakan Desert from April to June 2018. The retrievals of the reflectivity factor, dust spectrum distribution and dust mass concentration were carried out with the power spectrum data detected by MMWR for three dust storm processes. The analysis shows that: The probability density distribution of dust conforms to the lognormal distribution. During the dust storm processes, the effective detection height of the reflectivity factor was within 2000 m and the range of the reflectivity factors was between-25 dBZ and 25 dBZ. During the floating dust period, the effective height of the dust spectrum distribution was lower than 300 m and the values of dust mass concentration were less than 31.62 μg·m-3,at a height of 200 m. Furthermore, during the blowing sand stage, the effective height of the dust spectrum distribution was normally lower than 600 m and the values of dust mass concentration were mainly less than 316.23 μg·m-3,at a height of 200 m. During the dust storm period, the effective height of the dust spectrum distributionexceeded1000 m; when the height was 100 m, the values of dust mass concentration were between 1220 μg∙m-3 and 42,146 μg∙m-3 and the average mass concentration was 9287 μg·m-3; whereas, the values of dust mass concentration were between 2 μg∙m-3 and 820 μg∙m-3 when the height was 1200m and the average mass concentration was 24 μg∙m-3. The relationship between the reflectivity factor Z and the dust mass concentration M isdefined as Z=651.6M0.796. Compared with the observational data from Grimm180 particle detector, the data of the retrieved dust mass concentration are basically accurate and this retrieved method proves to be feasible. Thus, the MMWR cans be used as a new device for quantitative monitoring of dust storms.

Beschreibung: Agricultural emissions are crucial to regional air quality in the autumn and spring due to the intense agricultural activities in Northeast China. However, information on rural ambient particulate matter (PM) in Northeast China is rare, limiting the accurate estimation of agricultural atmospheric particulate matter emissions. In this study, we monitored hourly ambient PM2.5 (PM with a diameter of less than 2.5 μm) concentrations and analyzed daily chemical components (i.e., water-soluble ions, trace elements, organic carbon, and element carbon) at a rural site in Northeast China during the autumn and spring and assessed the impact of agricultural activities on atmospheric PM2.5 concentrations. The results showed that the daily average concentrations of PM2.5 were 143 ± 109 (range: 39–539) μg m−3 from 19 October to 23 November 2017 (i.e., typical harvesting month) and 241 ± 189 (range: 97–976) μg m−3 from 1 April to 13 May 2018 (i.e., typical tilling month). In autumn, the ambient PM2.5 concentrations were high with a Southwest wind, while a Southeast wind caused high PM2.5 concentrations during spring in the rural site. The concentrations of selected water-soluble ions, trace elements, and carbonaceous fractions accounted for 33%, 4%, and 26% of PM2.5 mass concentrations, respectively, in autumn and for 10%, 5%, and 3% of PM2.5 mass concentrations, respectively, in spring. On the basis of the component analysis, straw burning, agricultural machinery, and soil dust driven by wind and tilling were the main contributors to high rural PM2.5 concentrations. In addition, the increasing coal combustion around the rural site was another important source of PM2.5.

Beschreibung: Using composite, regular, and partial regression analyses in the six consecutive seasons from spring of the El Niño–Southern Oscillation (ENSO)-/Indian Ocean Dipole (IOD)-developing year through summer following the ENSO/IOD mature phase, the individual and combined impacts of El Niño and positive Indian Ocean Dipole (pIOD) on the evolution of precipitation in China are diagnosed for the period 1950–2013. It is shown that the seasonal responses of precipitation in China to El Niño and pIOD events, and their relationship with the large-scale atmospheric circulations, differ from one season to another. For the pure El Niño years, there is a seasonal reversal of precipitation over southeastern and northwestern China, with deficient precipitation occurring in these two regions before the onset of anomalous wet conditions in the developing autumn. Meanwhile, North China tends to be drier than normal in the developing seasons, but wetter than normal in the decaying seasons. For the pure pIOD events, southern China suffers a precipitation deficit (surplus) in the developing spring (summer and autumn). Furthermore, both North China and northwestern China experience excessive precipitation in the developing autumn and decaying summer. In addition, there is reduced precipitation in northeastern China during both the developing and decaying summers, whereas increased precipitation occurs in the developing autumn and decaying winter. For the combined years, southern China experiences enhanced moisture supply and suffers from increased precipitation from the developing summer through the subsequent spring, but reduced precipitation in the developing spring and decaying summer. Similar to the pure El Niño, northwestern (North) China becomes wetter than normal after the developing summer (autumn) in the combined years. In general, the ENSO/IOD-related precipitation variability could be explained by the associated anomaly circulations.

Beschreibung: Coffee grounds are the most significant production waste in the coffee industry and contain about 15% coffee oil. Coffee oil is rich in fatty acids and polyphenols, which have great application potential in the flotation of oxidized minerals. In this study, coffee oil as a green flotation collector for ilmenite was investigated by micro-flotation, zeta potential measurement, and foam stability analysis. The results of zeta potential reveal that both coffee oil and MOH can be adsorbed on the ilmenite surface at pH 6.7, and the chemical adsorption mode is dominant. However, when the pH is 2.8, the adsorption capacity of coffee oil on the ilmenite surface is much larger than that of MOH. The pH value of the pulp has little effect on the foam properties in the coffee oil solution and has a great influence on the foaming performance and foam stability of the MOH solution. When coffee oil is used as a collector, the grade of TiO2 in ilmenite concentrate is increased from 21.68% to 46.83%, and the recovery is 90.22%, indicating that the potential of coffee oil in the application of ilmenite flotation is large.

Beschreibung: Mars is a planet of great interest in the search for signatures of past or present life beyond Earth. The years of research, and more advanced instrumentation, have yielded a lot of evidence which may be considered by the scientific community as proof of past or present habitability of Mars. Recent discoveries including seasonal methane releases and a subglacial lake are exciting, yet challenging findings. Concurrently, laboratory and environmental studies on the limits of microbial life in extreme environments on Earth broaden our knowledge of the possibility of Mars habitability. In this review, we aim to: (1) Discuss the characteristics of the Martian surface and subsurface that may be conducive to habitability either in the past or at present; (2) discuss laboratory-based studies on Earth that provide us with discoveries on the limits of life; and (3) summarize the current state of knowledge in terms of direction for future research.

Beschreibung: The controlled crystallisation of struvite (MgNH4PO4∙6H2O) is a viable means for the recovery and recycling of phosphorus (P) from municipal and industrial wastewaters. However, an efficient implementation of this recovery method in water treatment systems requires a fundamental understanding of struvite crystallisation mechanisms, including the behavior and effect of metal contaminants during struvite precipitation. Here, we studied the crystallisation pathways of struvite from aqueous solutions using a combination of ex situ and in situ time-resolved synthesis and characterization techniques, including synchrotron-based small- and wide-angle X-ray scattering (SAXS/WAXS) and cryogenic transmission electron microscopy (cryo-TEM). Struvite syntheses were performed both in the pure Mg-NH4-PO4 system as well as in the presence of cobalt (Co), which, among other metals, is typically present in waste streams targeted for P-recovery. Our results show that in the pure system and at Co concentrations 〈 0.5 mM, struvite crystals nucleate and grow directly from solution, much in accordance with the classical notion of crystal formation. In contrast, at Co concentrations ≥ 1 mM, crystallisation was preceded by the transient formation of an amorphous nanoparticulate phosphate phase. Depending on the aqueous Co/P ratio, this amorphous precursor was found to transform into either (i) Co-bearing struvite (at Co/P 〈 0.3) or (ii) cobalt phosphate octahydrate (at Co/P 〉 0.3). These amorphous-to-crystalline transformations were accompanied by a marked colour change from blue to pink, indicating a change in Co2+ coordination in the formed solid from tetrahedral to octahedral. Our findings have implications for the recovery of nutrients and metals during struvite crystallisation and contribute to the ongoing general discussion about the mechanisms of crystal formation.

Beschreibung: Salt structures are attractive targets for hydrocarbon exploration. Salt can flow as a viscous fluid, act as hydrocarbon seal, and salt-related deformation may create reservoir traps. The high conductivity of salt can be crucial for hydrocarbon maturation in a basin. Here, we present results from the study of salt structures on the Eastern flank of Central Graben, on the Norwegian sector of the North Sea. By using our in-house basin modeling software (BMTTM), we modelled the salt structure evolution and the effects of salt on temperature and maturation. Our results show up to 85 °C cooling due to the salt heat pipe effect. An integrated impact of cooling is the depression of vitrinite Ro by up to 1.0% at the base of a large salt balloon. Our work shows that it is of critical importance to correctly identify salt volumes and to have a good geological model, and to understand the timing and geometrical evolution of salt structures. This study is, to our knowledge, the most specific analysis of the impact of salt on basin temperature and maturation published so far, and is an example of how basin modeling in the future should be an integrated part of exploration.

Beschreibung: In recent years data acquisition from remote sensing has become readily available to the quarry sector. This study demonstrates how such data may be used to evaluate and back analyse rockfall potential of a legacy slope in a blocky rock mass. Use of data obtained from several aerial LiDAR (Light Detection and Ranging) and photogrammetric campaigns taken over a number of years (2011 to date) provides evidence for potential rockfall evolution from a slope within an active quarry operation in Cornwall, UK. Further investigation, through analysis of point cloud data obtained from terrestrial laser scanning, was undertaken to characterise the orientation of discontinuities present within the rock slope. Aerial and terrestrial LiDAR data were subsequently used for kinematic analysis, production of surface topography models and rockfall trajectory analyses using both 2D and 3D numerical simulations. The results of an Unmanned Aerial Vehicle (UAV)-based 3D photogrammetric analysis enabled the reconstruction of high resolution topography, allowing one to not only determine geometrical properties of the slope surface and geo-mechanical characterisation but provide data for validation of numerical simulations. The analysis undertaken shows the effectiveness of the existing rockfall barrier, while demonstrating how photogrammetric data can be used to inform back analyses of the underlying failure mechanism and investigate potential runout.

Beschreibung: The accurate prediction of bus passenger flow is the key to public transport management and the smart city. A long short-term memory network, a deep learning method for modeling sequences, is an efficient way to capture the time dependency of passenger flow. In recent years, an increasing number of researchers have sought to apply the LSTM model to passenger flow prediction. However, few of them pay attention to the optimization procedure during model training. In this article, we propose a hybrid, optimized LSTM network based on Nesterov accelerated adaptive moment estimation (Nadam) and the stochastic gradient descent algorithm (SGD). This method trains the model with high efficiency and accuracy, solving the problems of inefficient training and misconvergence that exist in complex models. We employ a hybrid optimized LSTM network to predict the actual passenger flow in Qingdao, China and compare the prediction results with those obtained by non-hybrid LSTM models and conventional methods. In particular, the proposed model brings about a 4%–20% extra performance improvements compared with those of non-hybrid LSTM models. We have also tried combinations of other optimization algorithms and applications in different models, finding that optimizing LSTM by switching Nadam to SGD is the best choice. The sensitivity of the model to its parameters is also explored, which provides guidance for applying this model to bus passenger flow data modelling. The good performance of the proposed model in different temporal and spatial scales shows that it is more robust and effective, which can provide insightful support and guidance for dynamic bus scheduling and regional coordination scheduling.

Beschreibung: The future climate is projected to change rapidly with potentially severe consequences for global food security. This study aims to improve the understanding of future changes in the suitability of crop growth conditions. It proposes a definition of crop realization, of the climate departure from recent historical variability, or crop–climate departure. Four statistically downscaled and bias-corrected Global Climate Models (GCMs): CCCMA, CNRM5, NOAA-GFDL, and MIROC5 performed simulations for the period 1960–2100 under the Representative Concentration Pathway RCP8.5 scenario to compute 20 year moving averages at 5-year increments. These were used to drive a crop suitability model, Ecocrop, for eight different crops across the three Food and Agriculture Organizations (FAO) AgroEcological Zones (AEZs) of West Africa (Guinea, Sahel, and Savanna). Simulations using historical climate data found that all crops except maize had a suitability index value (SIV) ≥0.50 outside the Sahel region, equivalent to conditions being suitable or strongly suitable. Simulations of future climate reveal that warming is projected to constrain crop growth suitability for cassava and pineapple in the Guinea zone. A potential for the northward expansion of maize is projected by the end of the century, suggesting a future opportunity for its growth in the southern Sahel zone. Crop growth conditions for mango and pearl millet remain suitable across all three AEZs. In general, crops in the Savanna AEZ are the most sensitive to the projected changes in climate. The changes in the crop–climate relationship suggests a future constraint in crop suitability, which could be detrimental to future food security in West Africa. Further studies to explore associated short- and long-term adaptation options are recommended.

Beschreibung: We analyse Swarm satellite magnetic field and electron density data one month before and one month after 12 strong earthquakes that have occurred in the first 2.5 years of Swarm satellite mission lifetime in the Mediterranean region (magnitude M6.1+) or in the rest of the world (M6.7+). The search for anomalies was limited to the area centred at each earthquake epicentre and bounded by a circle that scales with magnitude according to the Dobrovolsky’s radius. We define the magnetic and electron density anomalies statistically in terms of specific thresholds with respect to the same statistical quantity along the whole residual satellite track (|geomagnetic latitude| ≤ 50°, quiet geomagnetic conditions). Once normalized by the analysed satellite tracks, the anomalies associated to all earthquakes resemble a linear dependence with earthquake magnitude, so supporting the statistical correlation with earthquakes and excluding a relationship by chance.

Beschreibung: An original source apportionment study was conducted on atmospheric particles (PM10) collected in Metz, one of the largest cities of Eastern France. A Positive matrix factorization (PMF) analysis was applied to a sampling filter-based chemical dataset obtained for the April 2015 to January 2017 period. Nine factors were clearly identified, showing mainly contributions from anthropogenic sources of primary PM (19.2% and 16.1% for traffic and biomass burning, respectively) as well as secondary aerosols (12.3%, 14.5%, 21.8% for sulfate-, nitrate-, and oxalate-rich factors, respectively). Wood-burning aerosols exhibited strong temporal variations and contributed up to 30% of the PM mass fraction during winter, while primary traffic concentrations remained relatively constant throughout the year. These two sources are also the main contributors during observed PM10 pollution episodes. Furthermore, the dominance of the oxalate-rich factor among other secondary aerosol factors underlines the role of atmospheric processing to secondary organic aerosol loadings which are still poorly characterized in this region. Finally, Concentration-Weighted Trajectory (CWT) analysis were performed to investigate the geographical origins of the apportioned sources, notably illustrating a significant transport of both nitrate-rich and sulfate-rich factors from Northeastern Europe but also from the Balkan region.

Beschreibung: We have developed a simple measuring system prototype that uses an unmanned aerial vehicle (UAV) and a non-dispersive infrared (NDIR) analyzer to detect regional carbon dioxide (CO2) concentrations and obtain vertical CO2 distributions. Here, we report CO2 measurement results for the lower troposphere above Ogata Village, Akita Prefecture, Japan (about 40° N, 140° E, approximately −1 m amsl), obtained with this UAV system. The actual flight observations were conducted at 500, 400, 300, 200, 100, and 10 m above the ground, at least once a month during the daytime from February 2018 to February 2019. The raw CO2 values from the NDIR were calibrated by two different CO2 standard gases and high-purity nitrogen (N2) gas (as a CO2 zero gas; 0 ppm). During the observation period, the maximum CO2 concentration was measured in February 2019 and the minimum in August 2018. In all seasons, CO2 concentrations became higher as the flight altitude was increased. The monthly pattern of observed CO2 changes is similar to that generally observed in the Northern Hemisphere as well as to surface CO2 changes simulated by an atmospheric transport model of the Japan Meteorological Agency. It is highly probable that these changes reflect the vegetation distribution around the study area.

Beschreibung: Bauxites in southern France (Provence and Languedoc) have been exploited since the beginning of the last century. Though most of the deposits are now subeconomic or mined-out, these bauxites represent model analogs for other economic bauxites of the world. These Cretaceous karst-type deposits lie directly on Jurassic carbonates, and have been formed through a combination of different processes: in-situ alteration of siliciclastic sediments deposited on carbonate platforms, and reworking of early bauxites in the karst network. In this study, we present preliminary bulk rock geochemical and in-situ laser ablation (LA) -ICP-MS analyses on Al- and Fe-oxy-hydroxides of Provence (Les Baux-de-Provence) and Languedoc (Villeveyrac, Loupian) bauxites, with the aim of evaluating the concentrations of rare earth elements (REEs) and their deportment in these minerals. REEs have total average concentrations of 700 mg/kg in the analyzed samples, which are mostly composed of boehmite, γ-AlO(OH), and Fe-oxy-hydroxides (hematite and goethite). Maximum REEs concentrations are commonly associated with positive Ce anomalies in chondrite-normalized patterns. In contrast with other examples from the literature, it has been observed that high REE concentrations also occur in samples apparently devoid or poor of REE-minerals. In these samples, the total amount of REEs is positively correlated with that of Ga (commonly contained in boehmite). LA-ICP-MS trace element analyses on boehmite and Fe-oxy-hydroxides have shown that while the Al-hydroxide contains the suite of REEs, goethite and hematite are preferentially enriched only in Ce. Considering that Al-hydroxides are digested during the Bayer process, an interesting issue to develop in the future is whether (and how) REEs released during Al-hydroxide digestion could be recovered together with Al from the pregnant leach liquor, as routinely done for Ga.

Beschreibung: This research aims to propose the use of spectral analysis of surface wave (SASW) tests along with in-situ suction measurements for non-destructive determination of shrinkage cracks. The underlying principle behind this proposed method is that, while suction and the small-strain shear modulus are positively correlated for intact samples, this is not the case for cracked ground. A series of SASW tests were performed on a clay embankment at different periods, during which the suction, modulus, and shrinkage crack depth varied seasonally. The soil water retention curve (SWRC) of the undisturbed sample collected from the cracked zone was determined, which related the suction-to-moisture content and void ratio of the soil. A free-free resonant frequency (FFR) test in the lab was conducted to determine the small-strain shear modulus (G0) at various moisture contents. The small-strain moduli from the SASW tests on the intact ground were generally higher than those from the FFR tests due to the effect of confining stress. A drop in the small-strain modulus determined using the SASW test was observed as an increase in suction-induced cracks and it relieved the horizontal stress. The crack depth measured in the field was then modelled using a semi-empirical procedure that can be used to predict crack depth relative to suction.

Beschreibung: This study aims to improve the implementation of models of geospatial information in Web Ontology Language (OWL). Large amounts of geospatial information are maintained in Geographic Information Systems (GIS) based on models according to the Unified Modeling Language (UML) and standards from ISO/TC 211 and the Open Geospatial Consortium (OGC). Sharing models and geospatial information in the Semantic Web will increase the usability and value of models and information, as well as enable linking with spatial and non-spatial information from other domains. Methods for conversion from UML to OWL for basic concepts used in models of geospatial information have been studied and evaluated. Primary conversion challenges have been identified with specific attention to whether adapted rules for UML modelling could contribute to improved conversions. Results indicated that restrictions related to abstract classes, unions, compositions and code lists in UML are challenging in the Open World Assumption (OWA) on which OWL is based. Two conversion challenges are addressed by adding more semantics to UML models: global properties and reuse of external concepts. The proposed solution is formalized in a UML profile supported by rules and recommendations and demonstrated with a UML model based on the Intelligent Transport Systems (ITS) standard ISO 14825 Geographic Data Files (GDF). The scope of the resulting ontology will determine to what degree the restrictions shall be maintained in OWL, and different conversion methods are needed for different scopes.

Beschreibung: The 3D road network scene helps to simulate the distribution of road infrastructure and the corresponding traffic conditions. However, the existing road modeling methods have limitations such as inflexibility in different types of road construction, inferior quality in visual effects and poor efficiency for large-scale model rendering. To tackle these challenges, a template-based 3D road modeling method is proposed in this paper. In this method, the road GIS data is first pre-processed before modeling. The road centerlines are analyzed to extract topology information and resampled to improve path accuracy and match the terrain. Meanwhile, the road network is segmented and organized using a hierarchical block data structure. Road elements, including roadbeds, road facilities and moving vehicles are then designed based on templates. These templates define the geometric and semantic information of elements along both the cross-section and road centerline. Finally, the road network scene is built by the construction algorithms, where roads, at-grade intersections, grade separated areas and moving vehicles are modeled and simulated separately. The proposed method is tested by generating large-scale virtual road network scenes in the World Wind, an open source software package. The experimental results demonstrate that the method is flexible and can be used to develop different types of road models and efficiently simulate large-scale road network environments.

Beschreibung: Coastal rural areas can be a source of elemental mercury, but the potential influence of their topographic and climatic particularities on gaseous elemental mercury (GEM) fluxes have not been investigated extensively. In this study, gaseous elemental mercury was measured over Mediterranean coastal grassland located in Northern Greece from 2014 to 2015 and GEM fluxes were evaluated utilizing Monin–Obukhov similarity theory. The GEM fluxes ranged from –50.30 to 109.69 ng m−2 h−1 with a mean value equal to 10.50 ± 19.14 ng m−2 h−1. Concerning the peak events, with high positive and low negative GEM fluxes, those were recorded from the morning until the evening. Rain events were a strong contributing factor for enhanced GEM fluxes. The enhanced turbulent mixing under daytime unstable conditions led to greater evasion and positive GEM fluxes, while, during nighttime periods, the GEM evasion is lower, indicating the effect of atmospheric stability on GEM fluxes. The coastal grassland with its specific characteristics influences the GEM fluxes and this area could be characterized as a source of elemental mercury. This study is one of the rare efforts in the research community to estimate GEM fluxes in a coastal natural site based on aerodynamic gradient method.

Beschreibung: Volatile organic compounds (VOCs) are important precursors to the formation of ozone and fine particulate matter, the two pollutants of most concern in Sydney, Australia. Despite this importance, there are very few published measurements of ambient VOC concentrations in Australia. In this paper, we present mole fractions of several important VOCs measured during the campaign known as MUMBA (Measurements of Urban, Marine and Biogenic Air) in the Australian city of Wollongong (34°S). We particularly focus on measurements made during periods when clean marine air impacted the measurement site and on VOCs of biogenic origin. Typical unpolluted marine air mole fractions during austral summer 2012-2013 at latitude 34°S were established for CO2 (391.0 ± 0.6 ppm), CH4 (1760.1 ± 0.4 ppb), N2O (325.04 ± 0.08 ppb), CO (52.4 ± 1.7 ppb), O3 (20.5 ± 1.1 ppb), acetaldehyde (190 ± 40 ppt), acetone (260 ± 30 ppt), dimethyl sulphide (50 ± 10 ppt), benzene (20 ± 10 ppt), toluene (30 ± 20 ppt), C8H10 aromatics (23 ± 6 ppt) and C9H12 aromatics (36 ± 7 ppt). The MUMBA site was frequently influenced by VOCs of biogenic origin from a nearby strip of forested parkland to the east due to the dominant north-easterly afternoon sea breeze. VOCs from the more distant densely forested escarpment to the west also impacted the site, especially during two days of extreme heat and strong westerly winds. The relative amounts of different biogenic VOCs observed for these two biomes differed, with much larger increases of isoprene than of monoterpenes or methanol during the hot westerly winds from the escarpment than with cooler winds from the east. However, whether this was due to different vegetation types or was solely the result of the extreme temperatures is not entirely clear. We conclude that the clean marine air and biogenic signatures measured during the MUMBA campaign provide useful information about the typical abundance of several key VOCs and can be used to constrain chemical transport model simulations of the atmosphere in this poorly sampled region of the world.

Beschreibung: This work focuses on the capabilities and limitations of the Advanced Satellite SAR (Synthetic Aperture Radar) Interferometry (A-DInSAR) in wooded and mountainous regions, with the aim to get insights on the performances for studying slow-moving landslides. The considered critical issues are related to the SAR acquisition geometries (angle of incidence of the satellite line of sight, ascending and descending geometries) and to the physical and morphological features of the slopes (land use, aspect and slope angles), which influence the measuring points coverage. 26 areas in Lombardy Region (Italy), affected by known slope instability phenomena, have been analyzed through A-DInSAR technique, using COSMO-SkyMed images. The results allowed to outline general considerations about the effectiveness of A-DInSAR analysis of a single dataset (descending or ascending dataset), selected accordingly to the aspect of the slopes. Moreover, we aimed to quantitatively describe the capability to update the state of activity of several previously mapped landslides using satellite SAR Interferometry results. Although in a wooded and mountainous region, where the chances of retrieving radar targets for satellite SAR analysis are generally low, the A-DInSAR results have allowed to detect landslides’ reactivations or new landslides and to update the inventory for about 70% of the investigated areas.

Beschreibung: The Qarhan Salt Lake has attracted increasing attention due to its significant national economic status and increased human activity, especially mining. Therefore, a sediment core collected from the confluence of the Golmud River to the Qarhan Salt Lake was chosen to investigate the concentrations, pollution levels, and ecological assessment of nine targeted elements (Al, As, Cd, Cr, Cu, Ni, P, Pb, and Zn). The excess 210Pb activities were calculated and a sedimentation rate of approximately 0.041 cm/y was estimated. Elements sources were identified, and the results show that Al, As, Cu, Ni, Pb, and Zn were mainly from natural sources, Cd and P were mainly from human input, and Cr appeared to have both sources. For Cd and P there was an increasing trend from 1987 and 1975, respectively, coinciding with the Chinese economic reform, Qarhan Salt Lake development and utilization, and also with the gross domestic product of Haixi State, Qinghai Province. Though the pollution and ecological assessment showed that there was nil to very low contamination and ecological risk, which is different from previous assumptions, the obviously increasing trend of Cd and P in the surface is still a concern. More attention should be paid to Cd and P in the further development of the Qarhan Salt Lake and the Golmud City.

Beschreibung: In this study, AERONET (Aerosol Robotic Network) and EARLINET (European Aerosol Research Lidar Network) data from 17 collocated lidar and sun photometer stations were used to characterize the optical properties of aerosol and their types for the 2008–2018 period in various regions of Europe. The analysis was done on six cluster domains defined using circulation types around each station and their common circulation features. As concluded from the lidar photometer measurements, the typical aerosol particles observed during 2008–2018 over Europe were medium-sized, medium absorbing particles with low spectral dependence. The highest mean values for the lidar ratio at 532 nm were recorded over Northeastern Europe and were associated with Smoke particles, while the lowest mean values for the Angstrom exponent were identified over the Southwest cluster and were associated with Dust and Marine particles. Smoke (37%) and Continental (25%) aerosol types were the predominant aerosol types in Europe, followed by Continental Polluted (17%), Dust (10%), and Marine/Cloud (10%) types. The seasonal variability was insignificant at the continental scale, showing a small increase in the percentage of Smoke during spring and a small increase of Dust during autumn. The aerosol optical depth (AOD) slightly decreased with time, while the Angstrom exponent oscillated between “hot and smoky” years (2011–2015) on the one hand and “dusty” years (2008–2010) and “wet” years (2017–2018) on the other hand. The high variability from year to year showed that aerosol transport in the troposphere became more and more important in the overall balance of the columnar aerosol load.

Beschreibung: A long-lived supercell developed in Northwest Bulgaria on 15 May 2018 and inflicted widespread damage along its track. The first part of this article presents a detailed overview of the observed storm evolution. Doppler radar observations reveal that the storm acquired typical supercellular signatures and maintained reflectivity values in excess of 63 dBZ for more than 4 h. The thunderstorm was also analyzed through lightning observations that highlighted important characteristics of the overall supercell dynamics. In its second part, the study investigates the predictability of the severe weather outbreak. In the medium forecast ranges, the global European Centre for Medium-Range Weather Forecasts (ECMWF) ensemble indicated the presence of favorable conditions for the development of deep moist convection 4 days prior to the event. A set of three convection-allowing ensemble simulations also demonstrated that the practical predictability of the supercell was approximately 12 h, which is considerably higher than some previously reported estimates. Nevertheless, the skill of the convective forecasts appears to be limited by the presence of typical model errors, such as the timing of convection initiation and the development of spurious convective activity. The relevance of these errors to the optimal ensemble size and to the design of future convection-allowing numerical weather prediction (NWP) systems is further discussed.

Beschreibung: The increasing frequency, intensity and duration of heat waves seem to follow the observed global warming in recent decades. Vulnerability to heat waves is expected to increase in urban environments mainly due to population density and the effect of the urban heat island that make cities hotter than surrounding non-urban areas. The present study focuses on a vulnerable area of the eastern Mediterranean, already characterized as a ‘hot spot’ with respect to heat-related risk and investigates the change in heat stress levels during heat wave compared to non-heat wave conditions as well as the way that heat stress levels respond to heat waves in urban, compared to non-urban, environments. The adoption of a metric accounting for both the intensity and duration of the hot event yielded a total of 46 heat wave episodes over a nearly 60-year period, but with very rare occurrence until the late 1990s and a profound increased frequency thereafter. The results reveal a difference of at least one thermal stress category between heat wave and non-heat wave periods, which is apparent across the entire range of the thermal stress distribution. The analysis demonstrates a robust intensification of nighttime heat stress conditions in urban, compared to non-urban, sites during severe heat waves. Nevertheless, severe heat waves almost equalize heat stress conditions between urban and non-urban sites during midday.

Beschreibung: The modular structure of the boundary layer and convection parameterizations in atmospheric models have long been affecting the numerical representation of subgrid-scale motions and their mutual interactions. A promising alternative, the eddy-diffusivity/mass-flux approach (EDMF), has the potential for unifying the existing formulations into a consistent scheme and improving some of the long-standing issues. This study documents a step towards developing such a unified approach by implementing a stochastic multi-plume EDMF scheme into the Community Atmosphere Model (Version 5.0). Its performance in single-column mode is evaluated against the control parameterization and large-eddy simulation (LES) for two benchmark cases: marine and continental shallow convection. Overall, the results for the two parameterizations agree well with each other and with LES in terms of mean profiles of moist conserved variables and their vertical fluxes, as well as the updraft properties. However, systematic differences between the two schemes, especially for transient continental convection, are also documented. Using EDMF helps improve some of the parameterized features of shallow convection. In particular, for the highest tested vertical resolution, the EDMF cloud base and top heights and the vertical fluxes of energy and water are remarkably close to LES.

Beschreibung: In this study, using Aerosol Robotic Network aerosol optical depth (AOD) products at three stations in the North China Plain (NCP)—a heavily polluted region in China—the AOD products from six satellite-borne radiometers: the Moderate Resolution Imagining Spectroradiometer (MODIS), the Multiangle Imaging Spectroradiometer (MISR), Ozone Mapping Imaging (OMI), the Visible Infrared Imaging Radiometer (VIIRS), the Sea-Viewing Wide Field-of-View Sensor (SeaWiFS), and Polarization and Directionality of the Earth’s Reflectances (POLDER), were thoroughly validated, shedding new light on their advantages and disadvantages. The MODIS Deep Blue (DB) products provide more accurate retrievals than the MODIS Dark Target (DT) and other satellite products at the Beijing site (BJ, a megacity), with higher correlations with AERONET (R 〉 0.93), lower mean absolute bias (MB 〈 0.012), and higher percentages (〉68%) falling within the expected error (EE). All MODIS DT and DB products perform better than the other satellite products at the Xianghe site (XH, a suburb). The MODIS/Aqua DT products at both 3-km and 10-km resolutions performed better than the other space-borne AOD products at the Xinglong site (XL, a rural area at the top of a mountain). MISR, VIIRS, and SeaWiFS tend to underestimate high AOD values and overestimate AOD values under very low AOD conditions in the NCP. Both OMI and POLDER significantly underestimate the AOD. In terms of data volume, MISR with the limited swath width of 380 km has less data volume than the other satellite sensors. MODIS products have the highest sampling rate, especially the MODIS DT and DB merged products, and can be used for various climate study and air-quality monitoring.

Beschreibung: The Asia Pacific Mercury Monitoring Network (APMMN) cooperatively measures mercury in precipitation in a network of sites operating in Asia and the Western Pacific region. The network addresses significant data gaps in a region where mercury emission estimates are the highest globally, and available measurement data are limited. The reduction of mercury emissions under the Minamata Convention on Mercury also justifies the need for continent-wide and consistent observations that can help determine the magnitude of the problem and assess the efficacy of reductions over time. The APMMN’s primary objectives are to monitor wet deposition and atmospheric concentrations of mercury and assist partners in developing their own monitoring capabilities. Network planning began in 2012 with wet deposition sampling starting in 2014. Currently, eight network sites measure mercury in precipitation following standardized procedures adapted from the National Atmospheric Deposition Program. The network also has a common regional analytical laboratory (Taiwan), and quality assurance and data flagging procedures, which ensure the network makes scientifically valid and consistent measurements. Results from our ongoing analytical and field quality assurance measurements show minimal contamination in the network and accurate analytical analyses. We are continuing to monitor a potential concentration and precipitation volume bias under certain conditions. The average mercury concentration in precipitation was 11.3 (+9.6) ng L−1 for 139 network samples in 2018. Concentrations for individual sites vary widely. Low averages compare to the low concentrations observed on the U.S. West Coast; while other sites have average concentrations similar to the high values reported from many urban areas in China. Future APMMN goals are to (1) foster new network partnerships, (2) continue to collect, quality assure, and distribute results on the APMMN website, (3) provide training and share best monitoring practices, and (4) establish a gaseous concentration network for estimating dry deposition.

Beschreibung: Studies in actual urban settings that integrate chemical reaction modeling, radiation, and particular emissions are mandatory to evaluate the effects of traffic-related air pollution on street canyons. In this paper, airflow patterns and reactive pollutant behavior for over 24 h, in a realistic urban canyon in Osaka City, Japan, was conducted using a computational fluid dynamics (CFD) model coupled with a chemical reaction model (CBM-IV). The boundary conditions for the CFD model were obtained from mesoscale meteorological and air quality models. Inherent street canyon processes, such as ground and wall radiation, were evaluated using a surface energy budget model of the ground and a building envelope model, respectively. The CFD-coupled chemical reaction model surpassed the mesoscale models in describing the NO, NO2, and O3 transport process, representing pollutants concentrations more accurately within the street canyon since the latter cannot capture the local phenomena because of coarse grid resolution. This work showed that the concentration of pollutants in the urban canyon is heavily reliant on roadside emissions and airflow patterns, which, in turn, is strongly affected by the heterogeneity of the urban layout. The CFD-coupled chemical reaction model characterized better the complex three-dimensional site and hour-dependent dispersion of contaminants within an urban canyon.

Beschreibung: In Africa, there is growing knowledge regarding the use of data obtained by remote sensing and analysed while using Geographic Information Systems for solving myriad problems. The awareness has largely arisen through the efforts of the Programme on Space Applications (PSA) of the United Nations Office for Outer Space Affairs (UNOOSA), and the subsequent UN resolutions for the establishment of Regional Centres for Space Science and Technology Education, to train scientists and researchers in different thematic areas of space, including Remote Sensing/Geographic Information Systems (RS/GIS). The African Regional Centre for Space Science and Technology Education in English (ARCSSTE-E) is one of these regional centres. The Centre has successfully trained 474 professionals from 18 countries since its inception in 1998; about 14% of these trainees have been female. This paper highlights the training programmes of ARCSSTE-E from its inception, and discusses the potential areas of improvement with a focus on the RS/GIS area. In 2019, a survey was conducted on alumni of the Postgraduate Diploma (PGD) programme of ARCSSTE-E. Based on the analysis of their responses and the progression of the PGD programme to a new Masters programme in RS/GIS at the university, there is clear evidence regarding the impact of the UNOOSA-assisted capacity building programme on the work and career of alumni, which has already produced an appreciable number of trained personnel in developing countries in Africa.

Beschreibung: Conventional Geographical Information Systems (GIS) software struggles to represent uncertain and contested historical knowledge. An ontology, meaning a semantic structure defining named entities, and explicit and typed relationships, can be constructed in the absence of locational data, and spatial objects can be attached to this structure if and when they become available. We describe the overall architecture of the Great Britain Historical GIS, and the PastPlace Administrative Unit Ontology that forms its core. Then, we show how particular historical geographies can be represented within this architecture through two case studies, both emphasizing entity definition and especially the application of a multi-level typology, in which each “unit” has an unchanging “type” but also a time-variant “status”. The first includes the linked systems of Poor Law unions and registration districts in 19th century England and Wales, in which most but not all unions and districts were coterminous. The second case study includes the international system of nation-states, in which most units do not appear from nothing, but rather gain or lose independence. We show that a relatively simple data model is able to represent much historical complexity.

Beschreibung: Ocean salinity variability provides a new way to study the evolution of the the El Niño-Southern Oscillation (ENSO). Comparisons between the salinity variation and related processes responsible for sea surface temperature anomaly (SSTA) were extensively examined for the two strong El Niño (EN) events in 1997/1998 and 2015/2016, and a special EN event in 2014/2015. The results show that the development of EN is significantly correlated with a sea surface salinity anomaly (SSSA) in the tropical western-central Pacific. In the spring of 1997 and 2015 with strong EN events, the western-central equatorial Pacific exhibited significant negative SSSA that propagated eastward to the west of the dateline. The negative SSSA induced increased barrier layer thickness (BLT) which enhanced sea surface temperature (SST) warming in the tropical central Pacific. In contrast, although a negative SSSA occurred during April of the 2014/2015 weak EN event in the western-central equatorial Pacific, this SSSA was mainly confined to between 160° E and 180° E without significant eastward movement, resulting in a weakened BLT thickening process and a weak modulation effect on SST. We also confirm that the surface forcing associated with fresh water flux (FWF: evaporation (E) minus precipitation (P)) plays a prominent role in the surface salinity tendency in the tropical Pacific during EN events. Moreover, the negative FWF anomaly leads a strong negative SSSA by two months. Compared with the two strong ENs, the early negative FWF anomaly in the weak 2014/2015 EN did not present distinct development and eastward propagation and weakened rapidly in the summer of 2015. We demonstrate that change in salinity can modulate the ENSO, and the variation of SSSA and associated physical processes in the tropical western-central Pacific and could be used as an indicator for predicting the development of ENSO.

Beschreibung: Contribution of extra-tropical synoptic cyclones to the formation of mean summer atmospheric circulation patterns in the Arctic domain (≥60° N) was investigated by clustering dominant Arctic circulation patterns based on daily mean sea-level pressure using self-organizing maps (SOMs). Three SOM patterns were identified; one pattern had prevalent low-pressure anomalies in the Arctic Circle (SOM1), while two exhibited opposite dipoles with primary high-pressure anomalies covering the Arctic Ocean (SOM2 and SOM3). The time series of their occurrence frequencies demonstrated the largest inter-annual variation in SOM1, a slight decreasing trend in SOM2, and the abrupt upswing after 2007 in SOM3. Analyses of synoptic cyclone activity using the cyclone track data confirmed the vital contribution of synoptic cyclones to the formation of large-scale patterns. Arctic cyclone activity was enhanced in the SOM1, which was consistent with the meridional temperature gradient increases over the land–Arctic ocean boundaries co-located with major cyclone pathways. The composite daily synoptic evolution of each SOM revealed that all three SOMs persisted for less than five days on average. These evolutionary short-term weather patterns have substantial variability at inter-annual and longer timescales. Therefore, the synoptic-scale activity is central to forming the seasonal-mean climate of the Arctic.

Beschreibung: Dritsite, ideally Li2Al4(OH)12Cl2·3H2O, is a new hydrotalcite supergroup mineral formed as a result of diagenesis in the halite−carnallite rock of the Verkhnekamskoe salt deposit, Perm Krai, Russia. Dritsite forms single lamellar or tabular hexagonal crystals up to 0.25 mm across. The mineral is transparent and colourless, with perfect cleavage on {001}. The chemical composition of dritsite (wt. %; by combination of electron microprobe and ICP−MS; H2O calculated by structure refinement) is: Li2O 6.6, Al2O3 45.42, SiO2 0.11, Cl 14.33, SO3 0.21, H2Ocalc. 34.86, O = Cl − 3.24, total 98.29. The empirical formula based on Li + Al + Si = 6 apfu (atom per formula unit) is Li1.99Al4.00Si0.01[(OH)12.19Cl1.82(SO4)0.01]Σ14.02·2.60(H2O). The Raman spectroscopic data indicate the presence of O–H bonding in the mineral, whereas CO32– groups are absent. The crystal structure has been refined in the space group P63/mcm, a = 5.0960(3), c = 15.3578(13) Å, and V = 345.4(5) Å3, to R1 = 0.088 using single-crystal data. The strongest lines of the powder X-ray diffraction pattern (d, Å (I, %) (hkl)) are: 7.68 (100) (002), 4.422 (61) (010), 3.832 (99) (004, 012), 2.561 (30) (006), 2.283 (25) (113), and 1.445 (26) (032). Dritsite was found as 2H polytype, which is isotypic with synthetic material and shows strong similarity to chlormagalumite-2H. The mineral is named in honour of the Russian crystallographer and mineralogist Prof. Victor Anatol`evich Drits.

Beschreibung: The divergence problem, which manifests as an unstable response relationship between tree-ring growth and climatic factors under the background of global warming, poses a challenge to both the traditional theory of dendroclimatology and the reliability of climatic reconstructions based on tree-ring data. Although Schrenk spruce, as the dominant tree species in the Tianshan Mountains, is frequently applied in the dendrochronological studies, the understanding of the divergence problem of this tree species is still limited. This study conducted correlation analysis between climatic factors and tree-ring width chronologies from 51 living and healthy specimens of Schrenk spruce at sites of high and low elevation in the Alatau Mountains to determine the stability of the response. The results revealed that the tree-ring width of the spruce specimens was correlated positively with precipitation and correlated negatively with temperature. Although the variations of the two tree-ring chronologies were similar, the radial growth of the spruce at the low elevation was found more sensitive to climatic factors. Furthermore, the sensitivity of tree growth to climate demonstrated an obvious increase after an abrupt change of climate under the background of the recent warming and wetting trend. Increased drought stress, calculated based on climatic data, was regarded as the main reason for this phenomenon. The results supply the gap of the stability of climatic response of tree growth in Central Asia to some extent.

Beschreibung: The measured concentrations of inorganic pollutants, such as ozone (2015–2018), sulfur, and nitrogen oxides (2012–2018) at air monitoring sites in the south of Eastern Siberia were sampled, following the passive sampling method, and analyzed. The spatial inhomogeneity of atmospheric gas concentrations is presented. The ozone concentration is lower in urban areas than those in rural areas and the background level. However, the nitrogen and sulfur oxide concentrations are higher in the atmosphere over the city site. The seasonal dependence of the ozone concentration was determined using its maximum (March–April) and minimum (September–October) levels. The dynamics of the nitrogen and sulfur oxide concentrations indicate that they are at their highest in December–June and their lowest in July–August. To verify the validity of the pollutant concentration measurements sampled by passive sampling, we compared our results with those obtained following the automatic and filter pack methods. A linear regression analysis and a pairwise modification of Student’s t test evaluated the concentrations of the air pollutant, sampled and measured using different methods, and they correlate well (r = 0.7–0.9). Full validation of the passive sampling method is not possible for some sites; therefore it is necessary to remove the remaining systematic errors in future work.

Beschreibung: Amphiboles are an important family of rock forming minerals, whose identification is crucial in provenance studies as well as in many other fields of geology, archaeology and environmental sciences. This study is aimed to find a quick way to characterize Ca-amphiboles in the tremolite (Ca2Mg5Si8O22(OH)2)–ferro–actinolite (Ca2Fe5Si8O22(OH)2) series. Raman spectroscopy is established as technique to perform non-destructive and quick analysis, with micrometric resolution, able to give the composition in terms of Mg/(Mg + Fe2+) ratio. To exploit the method, a preliminary characterization is performed by Scanning Electron Microscopy coupled with Energy-dispersed X-ray Spectroscopy (SEM-EDS). Two independent methods to evaluate the composition from the Raman data (aiming to an accuracy of about 5%), using the low-wavenumbers part of the spectrum and the OH stretching bands, are developed. The application of the proposed method to micro-Raman mappings and the possible use of handheld Raman spectroscopy to have compositional information on Ca-amphiboles are discussed.

Beschreibung: The primary stratigraphic fabric of a chaotic rock unit in the Zermatt Saas ophiolite of the Western Alps was reworked by a polyphase Alpine tectonic deformation. Multiscalar structural criteria demonstrate that this unit was deformed by two ductile subduction-related phases followed by brittle-ductile then brittle deformation. Deformation partitioning operated at various scales, leaving relatively unstrained rock domains preserving internal texture, organization, and composition. During subduction, ductile deformation involved stretching, boudinage, and simultaneous folding of the primary stratigraphic succession. This deformation is particularly well-documented in alternating layers showing contrasting deformation style, such as carbonate-rich rocks and turbiditic serpentinite metasandstones. During collision and exhumation, deformation enhanced the boudinaged horizons and blocks, giving rise to spherical to lozenge-shaped blocks embedded in a carbonate-rich matrix. Structural criteria allow the recognition of two main domains within the chaotic rock unit, one attributable to original broken formations reflecting turbiditic sedimentation, the other ascribable to an original sedimentary mélange. The envisaged geodynamic setting for the formation of the protoliths is the Jurassic Ligurian-Piedmont ocean basin floored by mostly serpentinized peridotites, intensely tectonized by extensional faults that triggered mass transport processes and turbiditic sedimentation.

Beschreibung: Morphologically diverse organo-sedimentary structures (including microbial mats and stromatolites) provide a palaeobiological record through more than three billion years of Earth history. Since understanding much of the Archaean fossil record is contingent upon proving the biogenicity of such structures, mechanistic interpretations of well-preserved fossil microbialites can reinforce our understanding of their biogeochemistry and distinguish unambiguous biological characteristics in these structures, which represent some of the earliest records of life. Mechanistic morphogenetic understanding relies upon the analysis of geomicrobiological experiments. Herein, we report morphological-biogeochemical comparisons between micromorphologies observed in growth experiments using photosynthetic mats built by the cyanobacterium Coleofasciculus chthonoplastes (formerly Microcoleus) and green anoxygenic phototrophic Chloroflexus spp. (i.e., Coleofasciculus–Chloroflexus mats), and Precambrian organo-sedimentary structures, demonstrating parallels between them. In elevated ambient concentrations of Cu (toxic to Coleofasciculus), Coleofasciculus–Chloroflexus mats respond by forming centimetre-scale pinnacle-like structures (supra-lamina complexities) associated with large quantities of EPS at their surfaces. µPIXE mapping shows that Cu and other metals become concentrated within surficial sheath-EPS-Chloroflexus-rich layers, producing density-differential micromorphologies with distinct fabric orientations that are detectable using X-ray computed micro-tomography (X-ray µCT). Similar micromorphologies are also detectable in stromatolites from the 3.481 Ga Dresser Formation (Pilbara, Western Australia). The cause and response link between the presence of toxic elements (geochemical stress) and the development of multi-layered topographical complexities in organo-sedimentary structures may thus be considered an indicator of biogenicity, being an indisputably biological and predictable morphogenetic response reflecting, in this case, the differential responses of Coleofasciculus and Chloroflexus to Cu. Growth models for microbialite morphogenesis rely upon linking morphology to intrinsic (biological) and extrinsic (environmental) influences. Since the pinnacles of Coleofasciculus–Chloroflexus mats have an unambiguously biological origin linked to extrinsic geochemistry, we suggest that similar micromorphologies observed in ancient organo-sedimentary structures are indicative of biogenesis. An identical Coleofasciculus–Chloroflexus community subjected to salinity stress also produced supra-lamina complexities (tufts) but did not produce identifiable micromorphologies in three dimensions since salinity seems not to negatively impact either organism, and therefore cannot be used as a morphogenetic tool for the interpretation of density-homogeneous micro-tufted mats—for example, those of the 3.472 Ga Middle Marker horizon. Thus, although correlative microscopy is the keystone to confirming the biogenicity of certain Precambrian stromatolites, it remains crucial to separately interrogate each putative trace of ancient life, ideally using three-dimensional analyses, to determine, where possible, palaeoenvironmental influences on morphologies. Widespread volcanism and hydrothermal effusion into the early oceans likely concentrated toxic elements in early biomes. Morphological diversity in fossil microbialites could, therefore, reflect either (or both of) differential exposure to ambient fluids enriched in toxic elements and/or changing ecosystem structure and tolerance to elements through evolutionary time—for example, after incorporation into enzymes. Proof of biogenicity by deducing morphogenesis (i.e., a process preserved in the fossil record) overcomes many of the shortcomings inherent to the proof of biogenicity by descriptions of morphology alone.

Beschreibung: Pyrochlore group minerals are the main raw phases in granitic rocks of the Katugin complex-ore deposit that stores Nb, Ta, Y, REE, U, Th, Zr, and cryolite. There are three main types: Primary magmatic, early postmagmatic (secondary-I), and late hydrothermal (secondary-II) pyrochlores. The primary magmatic phase is fluornatropyrochlore, which has high concentrations of Na2O (to 10.5 wt.%), F (to 5.4 wt.%), and REE2O3 (to 17.3 wt.%) but also low CaO (0.6–4.3 wt.%), UO2 (to 2.6 wt.%), ThO2 (to 1.8 wt.%), and PbO (to 1.4 wt.%). Pyrochlore of this type is very rare in nature and is limited to a few occurrences: Rare-metal deposits of Nechalacho in syenite and nepheline syenite (Canada) and Mariupol in nepheline syenite (Ukraine). It may have crystallized synchronously with or slightly later than melanocratic minerals (aegirine, biotite, and arfvedsonite) at the late magmatic stage when Fe from the melt became bound, which hindered the crystallization of columbite. Secondary-I pyrochlore follows cracks or replaces primary pyrochlore in grain rims and is compositionally similar to the early phase, except for lower Na2O concentrations (2.8 wt.%), relatively low F (4 wt.%), and less complete A- and Y-sites occupancy. Secondary-II pyrochlore is a product of late hydrothermal alteration, which postdated the formation of the Katugin deposit. It differs in large ranges of elements and contains minor K, Ba, Pb, Fe, and significant Si concentrations but also low Na and F. Its composition mostly falls within the field of hydro- and keno-pyrochlore.

Beschreibung: This study aims to address hydrological processes and impacts of an atmospheric river (AR) event that occurred during 15–18 February 2004 in the Russian River basin in California. The National Water Model (NWM), a fully distributed hydrologic model, was used to evaluate the hydrological processes including soil moisture flux, overland flow, and streamflow. Observed streamflow and volumetric soil water content data were used to evaluate the performance of the NWM using various error metrics. The simulation results showed that this AR event (15–18 February 2004) with a long duration of precipitation could cause not only deep soil saturation, but also high direct runoff depth. Taken together, the analysis revealed the complex interaction between precipitation and land surface response to the AR event. The results emphasize the significance of a change of water contents in various soil layers and suggest that soil water content monitoring could aid in improving flood forecasting accuracy caused by the extreme events such as the AR.

Beschreibung: In this study, based on daily precipitation records during 1958–2017 from 28 meteorological stations in the Beijing-Tianjin-Hebei (BTH) region, the spatio-temporal variations in precipitation extremes defined by twelve indices are analyzed by the methods of linear regression, Mann-Kendall test and continuous wavelet transform. The results showed that the spatial patterns of all the indices except for consecutive dry days (CDD) and consecutive wet days (CWD) were similar to that of annual total precipitation with the high values in the east and the low value in the west. Regionally averaged precipitation extremes were characterized by decreasing trends, of which five indices (i.e., very heavy precipitation days (R50), very wet precipitation (R95p), extreme wet precipitation (R99p), max one-day precipitation (R × 1day), and max five-day precipitation (R × 5day)) exhibited significantly decreasing trends at 5% level. From monthly and seasonal scale, almost all of the highest values in R × 1day and R × 5day occurred in summer, especially in July and August due to the impacts of East Asian monsoon climate on inter-annual uneven distribution of precipitation. The significant decreasing trends in annual R×1day and R×5day were mainly caused by the significant descend in summer. Besides, the possible associations between precipitation extremes and large-scale climate anomalies (e.g., ENSO (El Niño Southern Oscillation), NAO (North Atlantic Oscillation), IOD (Indian Ocean Dipole), and PDO (Pacific Decadal Oscillation)) were also investigated using the correlation analysis. The results showed that the precipitation extremes were significantly influenced by ENSO with one-year ahead, and the converse correlations between the precipitation extremes and climate indices with one-year ahead and 0-year ahead were observed. Moreover, all the indices show significant two- to four-year periodic oscillation during the entire period of 1958–2017, and most of indices show significant four- to eight-year periodic oscillation during certain periods. The influences of climate anomalies on precipitation extremes were composed by different periodic components, with most of higher correlations occurring in low-frequency components.

Beschreibung: The recent development of high-resolution climate models offers a promising approach in improving the simulation of precipitation, clouds and temperature. However, higher grid spacing is also a promising feature to improve the simulation of snow cover. In particular, it provides a refined representation of topography and allows for an explicit simulation of convective precipitation processes. In this study we analyze the snow cover in a set of decade-long high-resolution climate simulation with horizontal grid spacing of 2.2 km over the greater Alpine region. Results are compared against observations and lower resolution models (12 and 50 km), which use parameterized convection. The simulations are integrated using the COSMO (Consortium for Small-Scale Modeling) model. The evaluation of snow water equivalent (SWE) in the simulation of present-day climate, driven by the ERA-Interim reanalysis, against an observational dataset, reveals that the high-resolution simulation clearly outperforms simulations with grid spacing of 12 and 50 km. The latter simulations underestimate the cumulative amount of SWE over Switzerland over the whole annual cycle by 33% (12 km simulation) and 56% (50 km simulation) while the high-resolution simulation shows a spatially and temporally averaged difference of less than 1%. Scenario simulations driven by GCM MPI-ESM-LR (2081–2090 RCP8.5 vs. 1991–2000) reveal a strong decrease of SWE over the Alps, consistent with previous studies. Previous studies had found that the relative decrease becomes gradually smaller with elevation, but this finding was limited to low and intermediate altitudes (as a 12 km simulation resolves the topography up to 2500 m). In the current study we find that the height gradient reverses sign, and relative reductions in snow cover increases above 3000 m asl, where important parts of the cryosphere are present. In addition, the simulations project a transition from permanent to seasonal snow cover at high altitudes, with potentially important impacts to Alpine permafrost. This transition and the more pronounced decline of SWE emphasize the value of the higher grid spacing. Overall, we show that high-resolution climate models offer a promising approach in improving the simulation of snow cover in Alpine terrain.

Beschreibung: China is experiencing severe PM2.5 (fine particles with a diameter of 2.5 μg or smaller) pollution problem. Little is known, however, about how the increasing concentration trend is spatially distributed, nor whether there are some areas that experience a stable or decreasing concentration trend. Managers and policymakers require such information to make strategic decisions and monitor progress towards management objectives. Here, we present a pixel-based linear trend analysis of annual PM2.5 concentration variation in China during the period 1999–2016, and our results provide guidance about where to prioritize management efforts and affirm the importance of controlling coal energy consumption. We show that 87.9% of the whole China area had an increasing trend. The drastic increasing trends of PM2.5 concentration during the last 18 years in the Beijing–Tianjin–Hebei region, Shandong province, and the Three Northeastern Provinces are discussed. Furthermore, by exploring regional PM2.5 pollution, we find that Tarim Basin endures a high PM2.5 concentration, and this should have some relationship with oil exploration. The relationship between PM2.5 pollution and energy consumption is also discussed. Not only energy structure reconstruction should be repeatedly emphasized, the amount of coal burned should be strictly controlled.

Beschreibung: Point-of-interest (POI) recommendation is one of the fundamental tasks for location-based social networks (LBSNs). Some existing methods are mostly based on collaborative filtering (CF), Markov chain (MC) and recurrent neural network (RNN). However, it is difficult to capture dynamic user’s preferences using CF based methods. MC based methods suffer from strong independence assumptions. RNN based methods are still in the early stage of incorporating spatiotemporal context information, and the user’s main behavioral intention in the current sequence is not emphasized. To solve these problems, we proposed an attention-based spatiotemporal gated recurrent unit (ATST-GRU) network model for POI recommendation in this paper. We first designed a novel variant of GRU, which acquired the user’s sequential preference and spatiotemporal preference by feeding the continuous geographical distance and time interval information into the GRU network in each time step. Then, we integrated an attention model into our network, which is a personalized process and can capture the user’s main behavioral intention in the user’s check-in history. Moreover, we conducted an extensive performance evaluation on two real-world datasets: Foursquare and Gowalla. The experimental results demonstrated that the proposed ATST-GRU network outperforms the existing state-of-the-art POI recommendation methods significantly regarding two commonly-used evaluation metrics.

Beschreibung: Complex natural disasters often cause people to suffer hardships, and they can cause a large number of casualties. A population that has been affected by a natural disaster is at high risk and desperately in need of help. Even with the timely assessment and knowledge of the degree that natural disasters affect populations, challenges arise during emergency response in the aftermath of a natural disaster. This paper proposes an approach to assessing the near-real-time intensity of the affected population using social media data. Because of its fatal impact on the Philippines, Typhoon Haiyan was selected as a case study. The results show that the normalized affected population index (NAPI) has a significant ability to indicate the affected population intensity. With the geographic information of disasters, more accurate and relevant disaster relief information can be extracted from social media data. The method proposed in this paper will benefit disaster relief operations and decision-making, which can be executed in a timely manner.

Beschreibung: Simultaneous leaching of seafloor massive sulfides (SMS) from Loki’s Castle on the Arctic Mid-Ocean Ridge (AMOR) and polymetallic nodules (PN) from Clarion Clipperton Zone (CCZ) of the Central Pacific Ocean was studied. Leaching tests were conducted using sulfuric acid and sodium chloride, at a temperature of 80 °C for 48 h under reflux. The effect of PN-to-SMS ratio was examined. It was shown that simultaneous leaching of two different types of marine resources was possible resulting in high dissolution rates of metals. The proposed process has many advantages as it does not require pyrometallurgical pretreatment, and yields solid products (i.e., silica, barite, elemental sulfur, albite, microcline, muscovite), which might be utilized for various industrial applications.

Beschreibung: This study compares the performance of five popular equal-area projections supported by Free and Open Source Software for Geo-spatial (FOSS4G)—Sinusoidal, Mollweide, Hammer, Eckert IV and Homolosine. A set of 21,872 discrete distortion vindicatrices were positioned on the ellipsoid surface, centred on the cells of a Snyder icosahedral equal-area grid. These indicatrices were projected on the plane and the resulting angular and distance distortions computed, all using FOSS4G. The Homolosine is the only projection that manages to minimise angular and distance distortions simultaneously. It yields the lowest distortions among this set of projections and clearly outclasses when only land masses are considered. These results also indicate the Sinusoidal and Hammer projections to be largely outdated, imposing too large distortions to be useful. In contrast, the Mollweide and Eckert IV projections present trade-offs between visual expression and accuracy that are worth considering. However, for the purposes of storing and analysing big spatial data with FOSS4G the superior performance of the Homolosine projection makes its choice difficult to avoid.

Beschreibung: The circular economy seeks to minimize the use of raw materials and waste generation. In this context, here we addressed the use of dunite mining tailings and subproducts to stabilize metal(oid)s in polluted soils. We first characterized the dunite mining tailings and subproducts, and a paradigmatic polluted soil in depth to determine their chemical and mineralogical properties. Experimental trials using Brassica juncea L. were performed to evaluate the impact of the two materials on vegetation growth, edaphic properties and pollutant stabilization yields. To this end, the plants were grown over 75 days in 1 kg pots containing the polluted soil amended with the dunite materials. Notably, both amendments caused a dramatic decrease in the available Zn and a moderate reduction in available Cu, Cd and Pb. In contrast, the concentration of available As was not modified. The cation exchange capacity (CEC) was improved by treatment with the amendments, allowing an increase in the biomass harvested. The immobilization mechanism achieved was probably due to an increase in pH and CEC. In conclusion, the dunite tailings and subproducts could be effective amendments for stabilizing polluted soil. This work paves the way for additional studies with distinct types of soils and conditions.

Beschreibung: Water transformation around Antarctica is recognized to significantly impact the climate. It is where the linkage between the upper and lower limbs of the Meridional Overturning Circulation (MOC) takes place by means of dense water formation, which may be affected by rapid climate change. Simulation results from the Community Earth System Model Last Millennium Ensemble (CESM–LME) are used to investigate the Weddell Sea Warm Deep Water (WDW) evolution during the Last Millennium (LM). The WDW is the primary heat source for the Weddell Sea (WS) and accounts for 71% of the Weddell Sea Bottom Water (WSBW), which is the regional variety of the Antarctic Bottom Water (AABW)—one of the densest water masses in the ocean bearing directly on the cold deep limb of the MOC. Earth System Models (ESMs) are known to misrepresent the deep layers of the ocean (below 2000 m), hence we aim at the upper component of the deep meridional overturning cell, i.e., the WDW. Salinity and temperature results from the CESM–LME from a transect crossing the WS are evaluated with the Optimum Multiparameter Analysis (OMP) water masses decomposition scheme. It is shown that, after a long–term cooling over the LM, a warming trend takes place at the surface waters in the WS during the 20th century, which is coherent with a global expression. The subsurface layers and. mainly. the WDW domain are subject to the same long–term cooling trend, which is decelerated after 1850 (instead of becoming warmer like the surface waters), probably due interactions with sea ice–insulated ambient waters. The evolution of this anomalous temperature pattern for the WS is clear throughout the three major LM climatic episodes: the Medieval Climate Anomaly (MCA), Little Ice Age (LIA) and late 20th century warming. Along with the continuous decline of WDW core temperatures, heat content in the water mass also decreases by 18.86%. OMP results indicate shoaling and shrinking of the WDW during the LM, with a ~6% decrease in its cross–sectional area. Although the AABW cannot be directly assessed from CESM–LME results, changes in the WDW structure and WS dynamics have the potential to influence the deep/bottom water formation processes and the global MOC.

Beschreibung: Structural pounding during earthquakes may cause substantial damage to colliding structures. The phenomenon is numerically studied using different models of collisions. The aim of the present paper is to propose an effective formula for the impact damping ratio, as a parameter of the impact force model used to study different problems of structural pounding under seismic excitations. Its accuracy has been verified by four various approaches. Firstly, for the case of collisions between two structural elements, the dissipated energy during impact has been compared to the loss of kinetic energy. In the second stage of verifications, the peak impact forces during single collision have been analyzed. Then, the accuracy of different equations have been verified by comparing the impact force time histories for the situation when a concrete ball is dropped on a rigid concrete surface. Finally, pounding between two structures during earthquakes has been studied. The results of the analysis focused on comparison between dissipated and kinetic energy show relatively low errors between calculated and assumed values of the coefficient of restitution when the proposed equation is used. In addition, the results of the comparison between experimentally and numerically determined peak impact forces during single collision confirm the effectiveness of the approach. The same conclusion has been obtained for the whole impact time history for collision between a ball and a rigid surface. Finally, the results of the comparative analysis, conducted for pounding between two structures during an earthquake, confirm the simulation accuracy when the proposed approach is used. The above conclusions indicate that the proposed formula for impact damping ratio, as a parameter of impact force model for simulation of earthquake-induced structural pounding, is very effective and accurate in numerical simulations in the case of different scenarios.

Beschreibung: The Djibouti Ville Drift is part of a contourite depositional system located on the southern side of the Djibouti Ville Seamount in the Alboran Sea (Western Mediterranean). The sedimentary record of a core located in the drift deposits has been characterized to achieve the possible sediment sources for the Saharan dust supply and the paleocurrent variability related to Mediterranean intermediate waters for the last 133 kyr. Three end-member grain-size distributions characterize the sediment record transported by the bottom current to address the different aeolian populations, i.e., coarse EM1, silty EM2, and fine EM3. For these particles, the most likely source areas are the Saharan sedimentary basins and deserts, as well as the cratonic basins of the Sahara-Sahel Dust Corridor. The prevalence of these main source areas is shown in the core record, where a noticeable change occurs during the MIS 5 to MIS 4 transition. Some punctual sediment inputs from the seamount have been recognized during sea-level lowstand, but there is no evidence of fluvial supply in the drift deposits. The paleocurrent reconstruction allows the characterizing of the stadial and cold periods by large increases in the mean sortable silt fraction and UP10, which point to an enhanced bottom current strength related to intermediate water masses. Conversely, interglacial periods are characterized by weaker bottom current activity, which is associated with denser deep water masses. These proxies also recorded the intensified Saharan wind transport that occurred during interstadial/stadial transitions. All these results point to the importance of combining sediment source areas with major climatic oscillations and paleocurrent variability in palaeoceanographic sedimentary archives, which may help to develop future climate prediction models.

Beschreibung: Arboreal epiphytes (plants residing in forest canopies) are present across all major climate zones and play important roles in forest biogeochemistry. The substantial water storage capacity per unit area of the epiphyte “bucket” is a key attribute underlying their capability to influence forest hydrological processes and their related mass and energy flows. It is commonly assumed that the epiphyte bucket remains saturated, or near-saturated, most of the time; thus, epiphytes (particularly vascular epiphytes) can store little precipitation, limiting their impact on the forest canopy water budget. We present evidence that contradicts this common assumption from (i) an examination of past research; (ii) new datasets on vascular epiphyte and epi-soil water relations at a tropical montane cloud forest (Monteverde, Costa Rica); and (iii) a global evaluation of non-vascular epiphyte saturation state using a process-based vegetation model, LiBry. All analyses found that the external and internal water storage capacity of epiphyte communities is highly dynamic and frequently available to intercept precipitation. Globally, non-vascular epiphytes spend 〈20% of their time near saturation and regionally, including the humid tropics, model results found that non-vascular epiphytes spend ~1/3 of their time in the dry state (0–10% of water storage capacity). Even data from Costa Rican cloud forest sites found the epiphyte community was saturated only 1/3 of the time and that internal leaf water storage was temporally dynamic enough to aid in precipitation interception. Analysis of the epi-soils associated with epiphytes further revealed the extent to which the epiphyte bucket emptied—as even the canopy soils were often 〈50% saturated (29–53% of all days observed). Results clearly show that the epiphyte bucket is more dynamic than currently assumed, meriting further research on epiphyte roles in precipitation interception, redistribution to the surface and chemical composition of “net” precipitation waters reaching the surface.

Beschreibung: A 10-year study of elevated severe thunderstorms was performed using The National Centers for Environmental Information Storm Events Database. A total of 80 elevated thunderstorm cases were identified, verified, and divided into “Prolific” and “Marginal” classes. These severe cases occurred at least 80 km away from, and on the cold side of, a surface boundary. The downdraft convective available potential energy (DCAPE), downdraft convective inhibition (DCIN), and their ratio are tools to help estimate the potential for a downdraft to penetrate through the depth of a stable surface layer. The hypothesis is that as the DCIN/DCAPE ratio decreases, there exists enhanced possibility of severe surface winds. Using the initial fields from the Rapid Refresh numerical weather prediction model, datasets of DCIN, DCAPE, and their ratio were created. Mann-Whitney U tests on the Prolific versus Marginal case sets were undertaken to determine if the DCAPE and DCIN values come from different populations for the two different case sets. Results show that the Prolific cases have values of DCIN closer to zero, suggesting the downdraft is able to penetrate to the surface causing severe winds. Thus, comparing DCIN and DCAPE is a viable tool in determining if downdrafts will reach the surface from elevated thunderstorms.

Beschreibung: The Gangdese metallogenic belt in Tibet is an important copper and iron polymetallic, metallogenic belt in western China. The Luobuzhen epithermal Au-Ag and Hongshan porphyry Cu deposits, as two new discovery deposits in the last few years, are located in the western Gangdese metallogenic belt. In this paper, we present quartz vein Rb-Sr isochron, zircon U-Pb and molybdenite Re-Os ages for a better understanding of the minerallogenetic epoch of the deposits. Geochronological data show that the Rb-Sr isochron age of a quartz vein in a Luobuzhen Au-Ag deposit is 21.1 ± 1.8 Ma (MSWD (mean standard weighted deviation) = 0.19), zircon U-Pb ages from diorite and granodiorite porphyry in Hongshan Cu deposit are 50.0 ± 0.4 Ma (MSWD = 0.94) and 23.7 ± 0.1 Ma (MSWD = 0.73), respectively, and a Re-Os isochron age of molybdenite in Hongshan Cu deposit is 23.0 ± 2.0 Ma (MSWD = 0.014). These data suggest that the Luobuzhen epithermal Au-Ag and Hongshan porphyry Cu deposits formed at ca. 23–21 Ma, which were controlled by the same magmatic hydrothermal events. Formation of both the Luobuzhen and Hongshan deposits were obviously earlier than the Miocene porphyry metallogenetic events in the Gangdese porphyry copper belt.

Beschreibung: This research aims to find the most ecological itineraries for urban mobility in a small city (eco-routes), where distances are rather short, but car dependence is really high. A real life citywide survey was carried out in the city of Caceres (Spain) with almost 100,000 inhabitants. Research was done on alternating routes, traffic, times of day, and weather conditions. The output of the study was to assess fuel consumption, CO2, and regulated pollutant emissions for different type of vehicles, routes, and drivers. The results show that in the case studied, urban roads had fewer emissions (CO2 and pollutants) but there was an increase in the population affected by pollutants. On the contrary, bypasses reduced travel time and congestion but increased fuel consumption and emissions. Traffic conditions had a greater influence on fuel consumption in petrol vehicles than diesel ones. Therefore, there must be a balanced distribution of traffic in order to minimize congestion, and at the same time to reduce emissions and the number of people affected by harmful pollution levels. There should be a combination of regulatory measures in traffic policies in order to achieve that balance by controlling access to city centres, limiting parking spaces, pedestrianization, and lowering traffic speeds in sensitive areas.

Beschreibung: Urban territorial expansion generated in the last decades has brought a series of consequences, such as the variation between urban and suburban weather conditions affecting indoor temperature and increasing electricity consumption derived from the use of cooling systems. Current approaches of simulation models in residential buildings use indoor environmental data for carrying out validations to propose hygrothermal comfort alternatives for the mitigation of the effects of the external environmental conditions on the interior spaces of dwellings. In this work, an hourly evaluation of both indoor and outdoor environmental parameters of two case studies in a tropical climate was carried out, by means of a whole-building simulation approach tool during a week representative of the warmest period of the year. The integration of the collected environmental data in the theoretical model allowed us to reduce the error range of the estimated indoor temperature with results in normalized mean bias error between 7.10% and −0.74% and in coefficient of variation of the root mean square error between 16.72% and 2.62%, in the different indoor zones of the case studies. At the same time, the energy assessment showed a difference of 33% in Case 1 and −217% in Case 2 for final electricity consumption.

Beschreibung: The impact of absorbing aerosols on climate is complex, with their potential positive or negative forcing, depending on many factors, including their height distribution and reflective properties of the underlying background. Measurement data is very limited, due to insufficient remote sensing methods dedicated to the retrieval of their vertical distribution. Columnar values of absorbing aerosol optical depth (AAOD) and single scattering albedo (SSA) are retrieved by the Aerosol Robotic Network (AERONET). However, the number of available results is low due to sky condition and aerosol optical depth (AOD) limitation. Presented research describes results of field campaigns in Strzyżów (South-East Poland, Eastern Europe) dedicated to the comparison of the absorption coefficient and SSA measurements performed with on-ground in-situ devices (aethalomter, nephelometer), small unmanned aerial system (UAS) carrying micro-aethalometer, as well as with lidar/ceilometer. An important aspect is the comparison of measurement results with those delivered by AERONET. Correlation of absorption to scattering coefficients measured on ground (0.79) and correlation of extinction on ground to AOD measured by AERONET (0.77) was visibly higher than correlation between AOD and AAOD retrieved by AERONET (0.56). Columnar SSA was weakly correlated with ground SSA (higher values of columnar SSA), which were mainly explained by hygroscopic effects, increasing scattering coefficient in ambient (wet conditions), and partly high uncertainty of SSA retrieval. AAOD derived with the use of profiles from UAS up to PBL height, was estimated to contribute in average to 37% of the total AAOD. A method of AAOD estimation, in the whole troposphere, with use of measured vertical profiles of absorption coefficient and extinction coefficient profiles from lidars was proposed. AAOD measured with this method has poor correlation with AERONET data, however for some measurements, within PBL, AAOD was higher than reported by AERONET, suggesting potential underestimation in photometric measurement under particular conditions. Correlation of absorption coefficient in profile to on ground measurements decrease with altitude. Measurements of SSA from drones agree well with ground measurements and are lower than results from AERONET, which suggests a larger contribution of absorbing aerosols. As an alternative for AAOD estimation in case of lack of AERONET AAOD data simple models are proposed, which base on AOD scaling with SSA measured with different methods. Proposed solution increase potential of absorption coefficient measurements in vertical profiles and columns of the atmosphere. Presented solutions make measurements of absorption coefficients in vertical profiles more affordable and allow rough estimation of columnar values for the whole atmosphere.

Beschreibung: The Franciscan Complex of California is characterized in part by the presence of mélanges. In general, mélange origins are attributed to sedimentary, tectonic, or diapiric processes—or a combination of these. Published reviews list the main features of mélanges characteristic of each type of origin. In this review, particular diagnostic features typical of sedimentary, tectonic, and diapiric mélanges are used to assess 15 specific mélanges, which in some cases have been interpreted in contrasting ways in the literature. The data do not support the view that most Franciscan mélanges were formed by sedimentary processes, but rather that both tectonic and sedimentary processes are important. There is little evidence that diapirism contributed significantly to Franciscan mélange genesis. Tectonic features present in most mélanges of subduction accretionary complexes create challenges in assessing mélange-forming processes. Notably, although tectonic overprints commonly mask the primary diagnostic fabric of sedimentary mélanges, some diagnostic features—such as depositional contacts, fossils in mélange matrix, and interlayering of mélange and non-mélange units—are critical to recognition of mélanges of sedimentary origin.

Beschreibung: An experimental study, implicated in the revealing of the conditions for the origin for Fe3+-bearing magnesiowüstite in the lithospheric mantle, was performed using Mössbauer spectroscopy of pre-synthesized samples. Experiments were carried out using a multi-anvil high-pressure split-sphere apparatus at 6.3–7.5 GPa, in the range of 1100–1650 °C in carbonate-metal, carbonate–oxide-metal, carbonate-oxide, carbide-oxide and carbonate–metal- sulphur systems. In three experimental series, oxygen fugacity gradient in the samples was created, which enabled the study of the processes of magnesiowüstite formation under oxidizing and reducing conditions (ΔlogfO2 (FMQ) values from −1 to −5). It was established that Fe3+-bearing magnesiowüstite can form both in assemblage with oxidized phases, such as carbonate or with reduced ones—metal, carbides, sulphides, graphite and diamond. According to the Mössbauer spectroscopy, the composition of synthesized magnesiowüstite varied within a range of Fe3+/ΣFe values from 0 to 0.3, with IV and VI coordination of Fe3+ depending on P, T, fO2, x-parameters. It was established that Fe3+-bearing magnesiowüstite formation processes under upper mantle P,T-conditions include redox reactions, with magnesiowüstite being (1) reductant or (2) product of interaction, (3) crystallization processes of magnesiowüstite from an oxidized melt, where magnesiowüstite acts as a sink for ferric iron and (4) iron disproportionation.

Beschreibung: Traffic–induced vibrations may constitute a considerable load to buildings. In this paper, vibrations transmitted through the ground caused by wheeled vehicles are considered. This phenomenon may cause cracking of plaster, cracks in load-bearing elements or even, in extreme cases, collapse of the whole structure. Measurements of vibrations of real structures are costly and laborious. Therefore, the aim of the present paper is to propose a method of using Bayesian networks combined with implementation of geoscience for assessment of impact of traffic–induced vibrations on residential buildings. Firstly, the experimental tests were performed on different buildings using specialized equipment taking into account five factors: Distance from the building to the edge of the road, condition of road surface, condition of the building, the absorption of soil and the type of vehicle. Then, probabilistic analyses applying Bayesian networks were conducted and two methods of assessing the information value (EVSI method and entropy method) were compared. Finally, the developed diagnostic–decision support model was tested, so as to verify the most important parameter, affecting the possibility of structural vibrations to occur. The results of the study clearly showed that the use of Bayesian networks was a very effective approach to assess the impact of traffic-induced vibrations. The developed algorithm could be successfully applied both to existing and planned buildings, for which the source of vibration is already present or may appear in the future.

Beschreibung: 3D city models are being extensively used in applications such as evacuation scenarios and energy consumption estimation. The main standard for 3D city models is the CityGML data model which can be encoded through the CityJSON data format. CityGML and CityJSON use polygonal modelling in order to represent geometries. True topological data structures have proven to be more computationally efficient for geometric analysis compared to polygonal modelling. In a previous study, we have introduced a method to topologically reconstruct CityGML models while maintaining the semantic information of the dataset, based solely on the combinatorial map (C-Map) data structure. As a result of the limitations of C-Map’s semantic representation mechanism, the resulting datasets could suffer either from semantic information loss or the redundant repetition of them. In this article, we propose a solution for a more efficient representation of geometry, topology and semantics by incorporating the C-Map data structure into the CityGML data model and implementing a CityJSON extension to encode the C-Map data. In addition, we provide an algorithm for the topological reconstruction of CityJSON datasets to append them according to this extension. Finally, we apply our methodology to three open datasets in order to validate our approach when applied to real-world data. Our results show that the proposed CityJSON extension can represent all geometric information of a city model in a lossless way, providing additional topological information for the objects of the model.

Beschreibung: We are now generating exponentially more data from more sources than a few years ago. Big data, an already familiar term, has been generally defined as a massive volume of structured, semi-structured, and/or unstructured data, which may not be effectively managed and processed using traditional databases and software techniques. It could be problematic to visualize easily and quickly a large amount of data via an Internet platform. From this perspective, the main aim of the paper is to test point data visualization possibilities of selected JavaScript Mapping Libraries to measure their performance and ability to cope with a big amount of data. Nine datasets containing 10,000 to 3,000,000 points were generated from the Nature Conservation Database. Five libraries for marker clustering and two libraries for heatmap visualization were analyzed. Loading time and the ability to visualize large data sets were compared for each dataset and each library. The best-evaluated library was a Mapbox GL JS (Graphics Library JavaScript) with the highest overall performance. Some of the tested libraries were not able to handle the desired amount of data. In general, an amount of less than 100,000 points was indicated as the threshold for implementation without a noticeable slowdown in performance. Their usage can be a limiting factor for point data visualization in such a dynamic environment as we live nowadays.

Beschreibung: A new method, staged flotation for effectively increasing the recovery of ultra-fine copper oxide ore with a new type of collector (ZH-1, C3-5 carbon chain xanthate) is proposed for the first time. The flotation process and mechanism were examined by flotation tests, entrainment rate analysis, laser particle size experiments and microscopic imagery as well as economic feasibility analysis. It was demonstrated that the collector isoamyl sodium xanthate (ISX) shows a good collection ability (recovery exceeded 95%) for azurite, but the recovery was relatively much lower for malachite (only near 80%) due to the different particle size distribution. The new type of xanthate ZH-1 has shown a high-efficiency collection performance for fine-grained malachite. The recovery achieved for −10 μm malachite was more than 95% when the ZH-1 dosage was 150 mg/L, while the average particle size of −10 μm malachite sharply increased from 4.641 μm to 9.631 μm. The batch flotation results indicated that the copper oxide flotation recovery increased from 79.67% to 83.38%, and the grade also raised from 18.08% to 18.14% after using the staged flotation technology with ZH-1 as collector during the flotation of −25 μm ore. It was confirmed that this technology was quite effective for the recovery of copper oxide at the Dishui Copper Processing Plant, which successfully increased its gross profit by 1.6 million US$ per year.

Beschreibung: Understanding the mineralogical and chemical characteristics of stone coal is imperative for exploring the thermal storage characteristics of stone coal. Two types stone coal (SCwt and SChc) were sampled from the pond of a stone coal mine in Henan province (China), and the chemical composition, phase composition, and thermal behavior of the stone coal were investigated. Furthermore, the petrography of the stone coal was studied in detail. The mineral phases of the stone coal were quartz, kaolinite, roscoelite, and goethite, as distinguished by reflected light microscopy and further proven by scanning electron microscope-energy dispersive spectrometer (SEM-EDS). The thermal conductivity of SCwt was 0.19 W m−1 K−1, while that of SChc was 0.24 W m−1 K−1. Stearic acid (SA) was blended with SCwt and SChc to prepare SA/SCwt and SA/SChc composites via an impregnation method, respectively. The thermogravimetric (TG) curves show that the loading capacity of SChc, at 17.40%, is higher than that of SCwt (16.63%). The thermal energy storage capacities of SA/SCwt and SA/SChc composites were 29.21 J g−1 and 33.02 J g−1 according to a differential scanning calorimetry (DSC) analysis. Therefore, SChc is a potential candidate for thermal storage applications due to more obvious thermal storage characteristics, including higher thermal conductivity and loading capacity.

Beschreibung: The spectral response to arsenic (As) stress of pine needles (Pinus densiflora Siebold and Zucc.) from an abandoned lead (Pb)–zinc (Zn) mine was investigated based on chemical and spectroscopic analyses. The correlation analysis between the content of As in needle samples and that of soils and spectral parameters of the needle samples were conducted. The results showed very high correlation between As content in pine needles and soils. The major spectral response of pine needles to the As stress were characterized by the increase in the green and red color reflectance, the decrease in the first derivatives at 1648 nm, and the shrink in the red absorption feature. These changes were caused by the pigment content loss and the structural changes of phenolic compounds in the pine needles due to the As content. The linear regression analysis with the stepwise method showed the first derivatives at 668 nm and 1648 nm were the most useful variables in the regression model for As content prediction in pine needles. The As index of pine needles could be used to detect As content in soils associated with As and heavy metals contamination and/or mineralization in coniferous forests.

Beschreibung: Ultramafic soils are characterized by severe edaphic conditions induced by a low content of essential nutrients, an adverse Ca/Mg ratio, a low water-holding capacity, and high contents of geogenic potentially toxic elements (PTEs), in particular Cr, Ni, and Co. These metals commonly exceed the content limits set by environmental agencies and governments, representing serious environmental risks for ecosystems and human health. In alpine environments, ultramafic soils are characterized by modest thickness and poor horizon differentiation. Several studies on ultramafic soils have shown that their properties may be directly related to the characteristics of the parent rocks, but most of these studies deal with soil chemistry, metal availability, isotopic composition, and pedological characterization. The aim of this research is to investigate how much the geotectonic characteristics of ultramafic bedrocks, such as the degree of serpentinization, metamorphic imprint, and deformation, may affect the mineralogical and chemical variations of ultramafic soils, including the occurrence and potential mobility of the PTEs. Using a multiscale and multi-analytical approach, we fully characterize the properties and mineralogical composition of soil profiles with different ultramafic parent rocks, i.e., partially serpentinized peridotite, massive serpentinites, and foliated serpentinites, sampled within the Voltri Massif High Pressure–Low Temperature (HP–LT) metaophiolite (Western Alps, Italy). Our results, related to soils located at comparable latitude, altitude, landscape position, and pedological environment, outline that the degree of serpentinization, the metamorphic imprint, and the deformation history of the ultramafic parent rocks are key factors influencing soil evolution, mineralogy, and chemistry, as well as PTEs distribution and mobility. Moreover, this study shows that the high content of Cr, Ni, and Co in the studied ultramafic soils has to be considered of geogenic origin and highlights the need for new approaches and methods to obtain indications on the potential contamination of natural or anthropogenic soils.

Beschreibung: Calcium atoms are often replaced by rare earth elements (REEs) in the lattice of fluorapatite (Ca10F2(PO4)6), making the phosphate ore an important potential rare earth resource. In this paper, the electronic properties of REEs (La, Ce, Nd and Y) bearing fluorapatite crystals have been investigated by density functional theory. Results of calculation indicated that the existence of REEs increased the cell parameters of fluorapatite in varying degrees. The REEs substitution made the Fermi level of fluorapatite to move to higher energy levels, making it easier to accept electrons. Except for Y, all the other REEs (La, Ce and Nd) showed that the electronic state mainly exists in the valence band. The Fermi level of REEs were mainly contributed by La5d, Ce4f, Nd4f and Y4d, respectively. The Mulliken values of REE–F and REE–O bonds in REEs-bearing fluorapatites were larger than those of Ca–F and Ca–O bonds in the perfect crystal, and the values of Y–F and Y–O bonds were the largest. The results of interaction between fluorapatite and oleic acid by frontier molecular orbital analysis suggested that the substitution of REEs can improve the reactivity of fluorapatite with oleic acid.

Beschreibung: In waste management, recycled and industrial aggregates (e.g., electric arc furnace (EAF) slags) for construction applications have to fulfil the limit values with respect to the total and/or leachable contents of potentially environmentally problematic chemical elements (PEPE, e.g., Cr, Ni, Cu, Mo, V). Natural aggregates, i.e., quarried hard rocks, are neither tested nor regulated for these parameters in most EU member states, e.g., Austria, prior to using them as a construction material. The purpose of this study was to relate the mineralogy to the leachability of natural aggregates with a special emphasis on PEPE and to interpret these findings in comparison with EAF slags. Five samples of Austrian rocks were investigated by polarization microscopy, electron probe microanalyses (EPMA), X-ray diffraction (XRD), and leaching tests as well as by hydrogeochemical modelling using LeachXSTM. Two samples showed elevated total contents of Cr, Ni, and Mo which were present as Cr-spinel, (Fe,Mg)(Al,Cr)2O4, Ni-olivine, (Fe,Mg,Ni)2SiO4, and molybdenite, MoS2. Whereas the former two phases also controlled the leaching of Cr and Ni, the observed leaching of Mo was higher than expected in the case of solubility control by molybdenite. In summary, the leachability of PEPE in natural and industrial aggregates was controlled by similar mineralogical mechanisms.

Beschreibung: The increasing demand for green technology and battery metals necessitates a review of geological exploration techniques for Li–Cs–Ta (LCT) pegmatites, which is applicable to the work of mining companies. This paper reviews the main controls of LCT pegmatite genesis relevant to mineral exploration programs and presents a workflow of grassroots exploration techniques, supported by examples from central Europe and Africa. Geological exploration commonly begins with information gathering, desktop studies and Geographic Information System (GIS) data reviews. Following the identification of prospective regional areas, initial targets are verified in the field by geological mapping and geochemical sampling. Detailed mineralogical analysis and geochemical sampling of rock, soil and stream sediments represent the most important tools for providing vectors to LCT pegmatites, since the interpretation of mineralogical phases, deportment and liberation characteristics along with geochemical K/Rb, Nb/Ta and Zr/Hf metallogenic markers can detect highly evolved rocks enriched in incompatible elements of economic interest. The importance of JORC (Joint Ore Reserves Committee) 2012 guidelines with regards to obtaining geological, mineralogical and drilling data is discussed and contextualised, with the requirement of treating LCT pegmatites as industrial mineral deposits.

Beschreibung: The organic-enriched thick shale at the bottom of Longmaxi Formation is laterally continuous distributed and has been proven to be of good production capability in Fuling of Upper Yangtze. Uplifts that developed during the sedimentation influenced the reservoir characteristics by taking control of the sedimentary environment and provenance. The sedimentary environments are mainly deep-water shelf, shallow-water shelf, and tidal flat. By analyzing reservoir characteristic of these three environments, the deep-water shelf, which dominated the early stage of sedimentation, formed a high-quality reservoir with high TOC (Total Organic Carbon) content, porosity, and brittleness, while the environment was maintained around the basin centre until the Early Silurian. The shales deposited under the shallow-water environment were of low porosity because of the increasing calcareous and argillaceous contents. Sediments which formed on the tidal flat were arenaceous and of the lowest TOC content as the organic preservation conditions deteriorated. The good correlation of graptolite abundance and TOC content, and high porosity within graptolite fossils emphasize the importance of palaeontological development. The argillaceous cap over the Longmaxi shale is of good sealing capability, and the continuous sedimentation zone along southern Sichuan–eastern Chongqing is the best optimized hydrocarbon-bearing system. However, a weak interface on the discontinuity is the potential lateral pathway for gas diffusion at Northern Guizhou and Western Hunan, but on the southeast margin where the dark shale and the tidal sandstone contact, it promises to form a tight gas reservoir.

Beschreibung: Plagioclase ultraphyric basalts (PUBs) with up to 40% millimeter-sized plagioclase crystals, were sampled from the Mount Jourdanne volcanic massif (~64° E) in the Southwest Indian Ridge. The geochemistry of the host glass, the glassy melt inclusions and their host plagioclase macrocrysts (An60-69) are used to reveal the mantle heterogeneity and to discuss the origin of Mount Jourdanne PUBs. The melt inclusions trapped in plagioclase display low MgO and high SiO2 contents and show rare earth element (REE) patterns resembling enriched mid-ocean ridge basalts (E-MORB). Together with their positive Sr and Eu anomalies, these features indicate that they were derived from an enriched mantle source, likely a refertilized peridotite or a pyroxenite. In contrast to some 61–67° E basalts, there is a lack of negative Eu anomalies in the PUB host glasses, precluding large amounts of plagioclase crystallization from their parental magma. Petrographic observations and the general chemical similarity between melt inclusions and melts equilibrated with the clinopyroxene cores in regional gabbros and/or troctolites suggest that these plagioclase macrocrysts originate from gabbroic mush within the lower crust. The density contrasts allow the effective segregation of plagioclase prior to their incorporation into the host magma. We propose that these plagioclase macrocrysts were entrained when a new batch of magma passed through the crustal mush zone, and resulted in the formation of the PUB. Eruption of Mount Jourdanne PUBs requires a minimum ascending velocity of 5 m d−1 for the host magma, which is not as high as the eruption rate for typical MORB samples. It is likely that the PUB host magma erupts during a period with reduced magma supply, whereas eruption of aphyric lavas correspond to the fast volcanic formation of the Mount Jourdanne massif.

Beschreibung: The eclogite-bearing Alag Khadny metamorphic complex in the Lake Zone, SW Mongolia occupies the central region of the Central Asian Orogenic Belt, the largest Phanerozoic orogenic belt in the world. The complex consists mainly of orthogneisses intercalated with eclogites and micaschists in a mélange zone. Most of eclogites are strongly amphibolitized. In this study, we examined petrography and mineral chemistry of eclogites and amphibolitized eclogites, respectively. The result of our research shows that Chandman eclogites experienced multiple events of metamorphism in throughout their subduction and subsequent collision history. We revealed that eclogites were subjected to blueschist facies metamorphism before the peak eclogite facies stage. In addition, we have studied amphibolitized eclogite, and revealed that another distinct progressive medium pressure (MP) epidote-amphibolite facies metamorphic event took place in the eclogite, consistent with collision process. The multiple events of metamorphism in eclogites have been revealed by zonation textures of HP amphiboles zoned with glaucophane→barroisite→Mg-hornblende and MP amphiboles zoned with actinolite/winchite→barroisite→Mg-hornblende/tschermakite/Fe-pargasite. These amphiboles with different zonation textures reflect their metamorphic history of subduction to collision events.

Beschreibung: Nature has been adversely affected by increasing industrialization, especially during the latter part of the last century, as a result of accelerating technological development, unplanned urbanization, incorrect agricultural policies and deforestation, which have contributed to the elevated concentration of the greenhouse gases (GHGs) in the environment. GHG accumulation has an adverse impact on meteorological and hydro-meteorological parameters, particularly temperature. Temperature plays a prominent and well-known role in evaporation, transpiration and changes in water demand, and thus significantly affects both water availability and food security. Therefore, a systematic understanding of temperature is important for fighting food insecurity and household poverty. Variations in temperature are often assessed and characterized through trend analysis. Hence, the objective of this paper is to determine long-term trends in mean monthly maximum and minimum air temperatures for the Maloti-Drakensberg region. The Mann–Kendall test, a non-parametric test, was applied on mean air temperature for the 1960–2016 period. A significant rising trend (p 〈 0.001) was detected with a yearly change in the long term annual mean maximum and mean minimum temperature by 0.03 °C/annum and 0.01 °C/annum, respectively. This knowledge has important implications for both the state of the environment and livelihoods in the region, since its use can be useful in planning and policymaking in water resource management, biodiversity conservation, agriculture, tourism and other sectors of the economy within the region.

Beschreibung: Subway air pollution mainly refers to inhalable particulate matter (PM) pollution, organic pollution, and microbial pollution. Based on the investigation and calculation of the existing researches, this paper summarizes the sources of air pollutants, chemical compositions, and driving factors of PM variations in subway. It evaluates the toxicity and health risks of pollutants. In this paper, the problems and challenges during the deployment of air pollution governance are discussed. Results show that the global PM compliance rate of subway is about 30%. Subway air pollution is endogenous, which means that pollutants mainly come from mechanical wear and building materials erosions. Particles are mainly metal particles, black carbon, and floating dust. The health risks of some chemical elements in the subway have reached critical levels. The variations of PM concentrations show spatial-temporal characteristics, which are mainly controlled by train age, brakes types, and environmental control systems. The authors then analyze the dynamics of interactions among government, companies and public during the air pollution governance by adding the following questions: (a) who pays the bill; (b) how to evaluate the cost-effectiveness of policies; (c) how the public moves from risk perception to actions; (d) how to develop clean air technology better so as to ultimately incentivize stakeholders and to facilitate the implementation of subway clean air programme in a resilient mode.

Beschreibung: Large-scale three-dimensional (3D) reconstruction from multi-view images is used to generate 3D mesh surfaces, which are usually built for urban areas and are widely applied in many research hotspots, such as smart cities. Their simplification is a significant step for 3D roaming, pattern recognition, and other research fields. The simplification quality has been assessed in several studies. On the one hand, almost all studies on surface simplification have measured simplification errors using the surface comparison tool Metro, which does not preserve sufficient detail. On the other hand, the reconstruction precision of urban surfaces varies as a result of homogeneity or heterogeneity. Therefore, it is difficult to assess simplification quality without surface classification. These difficulties are addressed in this study by first classifying urban surfaces into planar surfaces, detailed surfaces, and urban frameworks according to the simplification errors of different types of surfaces and then measuring these errors after sampling. A series of assessment indexes are also provided to contribute to the advancement of simplification algorithms.

Beschreibung: Prescribed pasture burning plays a critical role in ecosystem maintenance in tallgrass prairie ecosystems and may contribute to agricultural productivity but can also have negative impacts on air quality. Volatile organic compound (VOC) concentrations were measured immediately downwind of prescribed tallgrass prairie fires in the Flint Hills region of Kansas, United States. The VOC mixture is dominated by alkenes and oxygenated VOCs, which are highly reactive and can drive photochemical production of ozone downwind of the fires. The computed emission factors are comparable to those previous measured from pasture maintenance fires in Brazil. In addition to the emission of large amounts of particulate matter, hazardous air pollutants such as benzene and acrolein are emitted in significant amounts and could contribute to adverse health effects in exposed populations.