Global maps of soil temperature

Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-km2 resolution for 0–5 and 5–15 cm soil depth. These maps were created by calculating the difference (i.e. offset) between in situ soil temperature measurements, based on time series from over 1200 1-km2 pixels (summarized from 8519 unique temperature sensors) across all the world\u27s major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10°C (mean = 3.0 ± 2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 ± 2.3°C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (−0.7 ± 2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications

Global maps of soil temperature

Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-km² resolution for 0–5 and 5–15 cm soil depth. These maps were created by calculating the difference (i.e., offset) between in-situ soil temperature measurements, based on time series from over 1200 1-km² pixels (summarized from 8500 unique temperature sensors) across all the world’s major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10°C (mean = 3.0 ± 2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 ± 2.3°C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (-0.7 ± 2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in-situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications

Global maps of soil temperature.

Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-km2 resolution for 0-5 and 5-15 cm soil depth. These maps were created by calculating the difference (i.e. offset) between in situ soil temperature measurements, based on time series from over 1200 1-km2 pixels (summarized from 8519 unique temperature sensors) across all the world's major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10°C (mean = 3.0 ± 2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 ± 2.3°C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (-0.7 ± 2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications

Surface morphology and sulfur reduction pathways of MoS₂ Mo edges of the monolayer and (100) and (103) surfaces by molecular hydrogen:a DFT study

Abstract We have performed a density functional theory study of the MoS₂ monolayer and the MoS₂ (100) and (103) surfaces in relation to the early stages of the hydrodesulfurization reaction. In many X-ray diffraction (XRD) results, the (103) surface exhibits a higher peak than the (100) surface, yet one of the most frequently occurring surface has not been studied extensively. By analyzing experimental studies, we conclude that the (103) surface of MoS₂ is the most frequently occurring edge surface when the sample size is thicker than ∼10–15 nm. Herein, we report the first comparison of reaction paths for the formation of a sulfur vacancy on the (103) surface of MoS₂, monolayer, and (100) surface of MoS₂. The reason for the occurence of the (103) surface in the XRD patterns has been established. We point out the similarity in the reaction barriers for the monolayer and (100) and (103) surfaces and discuss the reason for it. Moreover, we found a more energetically favorable step in the reaction pathway for the formation of a sulfur vacancy, which allowed us to refine the previously established pathway

A DFT study of the effect of SO₄ groups on the properties of TiO₂ nanoparticles

Abstract We present a study of the optical, electronic, and structural properties of TiO₂ anatase-structured nanoparticles upon adsorption of SO₄ groups, which are always present on the surface of the particles during the sulfate manufacturing method. Structural and electronic properties were studied using the density functional theory method (DFT), and optical properties were obtained by time-dependent DFT. It was found that SO₄ groups alter both the geometric and electronic structure of TiO₂ nanoparticles and change the photoabsorption characteristics. In particular, we find that ɳ²-O₂ type O–O moieties are formed due to the adsorption of 3 and 4SO₄ groups

Ab initio study of hydrogen sensing in Pd and Pt functionalized GaN [0 0 0 1] nanowires

Abstract Using density functional theory based simulations, the adsorption of hydrogen on GaN nanowires with [0 0 0 1] orientation is studied with Pt and Pd functionalization. The adsorption energies show that both Pt and Pd prefer to attach to a top site above the Ga atom in the nanowire. In the pristine GaN, hydrogen attach as a molecule, while in the presence of Pt and Pd, it dissociates into atoms and adsorb through a chemical bonding. Change in Ga-N bond lengths are observed with hydrogen adsorption on the surface of the nanowire and the resultant strain as well as the charge transfer between atoms can be used as entities to understand the detection mechanism. From the electronic structure analysis, it is revealed that both Pt and Pd can be used to tune the band gap and are favorable adsorbates to enhance the hydrogen sensing properties of GaN nanowires. Pt turns out to be a more efficient adsorbate for hydrogen detection due to the lowered adsorption energies, compact Pt-H bond length and enhanced surface charge reconstruction

Adsorption of CO₂ on the ω-Fe (0001) surface:insights from density functional theory

Abstract The stabilization of a hexagonal phase known as the ω-phase in steel has recently been identified. The presence of C in steel samples is found to be helping the formation of this otherwise meta stable phase. This indicates that the probability of degradation of the surface is high in steel samples containing the ω-phase, through surface adsorption. Here we calculate the adsorption process of CO₂ on the ω-Fe(0001) surface, for different sites and find that it strongly adsorbs horizontally with a bent configuration. The adsorption is characterized by significant charge transfer from the surface Fe atoms to the CO₂ molecule, and structural modification of the molecule is occurring. The density of states calculations indicate that hybridization and subsequent charge transfer is probable between the d orbitals of Fe and p orbitals of CO₂, resulting in strong chemisorption, that further leads to spontaneous dissociation of the molecule

A qualitative study on the effects of real-world stimuli and place familiarity on presence

Abstract We present a qualitative study investigating the effects of real-world stimuli and place familiarity on presence. The study was carried out using a prototype Virtual Reality system designed for participatory urban planning. The system uses consumer grade VR hardware for viewing 3D virtual models of future architectural plans at an urban site. We collected comprehensive qualitative data from 16 participants who used the VR system on-site to immersively view and vote on three different future plans at the real-world location while exposed to ambient non-visual stimuli emanating from the physical location. We provide qualitative findings regarding presence along the four recurrent themes revealed by the thematic analysis of the research data: visual content, impact of physical surroundings, navigation and interaction, and suitability for participatory urban planning. We also analyse the findings in terms of feasibility of such on-site VR experience and the applicability of large-scale city models for VR

Two real-world case studies on 3D web applications for participatory urban planning

Abstract 3D Web is a potential platform for publishing and distributing 3D visualizations that have proven useful in enabling the participation of the general public in urban planning. However, technical requirements imposed by detailed and rich real-world plans and related functionalities are demanding for 3D web technologies. In this paper we explore the maturity of modern 3D web technologies in participatory urban planning through two real-world case studies. Applications built on Unity-based platform are published on the web to allow the general public to create, browse and comment on urban plans. The virtual models of seven urban development sites of different visual styles are optimized in terms of download sizes and memory use to be feasible on browsers used by the general public. We report qualitative feedback from users and present a technical analysis of the applications in terms of download sizes, runtime performance and memory use. We summarize the findings of the case studies into an assessment of the general feasibility of modern 3D web technologies in web-based urban planning