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

Synthesis, characterization and catalytic activity of Au supported on functionalized SBA-15 for low temperature CO oxidation

SBA-15 functionalization with 3-mercaptopropyltrimethoxysilane was used to prepare a supported gold catalyst for the low temperature CO oxidation reaction. Catalytic runs were performed at atmospheric pressure and T = 40–150 °C and the influence of different thermal treatments of the sample prior to reaction was studied. The modifications induced by the pre-treatments in the physicochemical properties of both the carrier and the disperse phase were investigated by chemical analysis, CHS elemental analysis, N2 adsorption–desorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), solid state cross-polarization magic-angle-spinning nuclear magnetic resonance spectroscopy (CPMAS NMR) of 29Si and 13C and Fourier transform infrared spectroscopy (FTIR). The pre-treatment conditions were found to strongly affect both the gold particle size and the nature of the Au surface species. An appreciable catalytic activity was found on samples treated at 600 °C in H2/He atmosphere, provided that the functionalizing agent had been completely removed by a previous high-temperature calcination