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Key long-lived greenhouse gases (CO2, CH4, and N2O) are perhaps among the best-studied components of the Earth's atmosphere today; however, attempts to predict or explain trends or even shorter-term variations of these trace gases are not always successful. Infrared spectroscopy is a recognized technique for the ground-based long-term monitoring of the gaseous composition of the atmosphere. The current paper is focused on the analysis of new data on CO2, CH4, and N2O total columns (TCs) retrieved from high resolution IR solar spectra acquired during 2009–2022 at the NDACC atmospheric monitoring station of St. Petersburg State University (STP station, 59.88°N, 29.83°E, 20 m asl.). The paper provides information on the FTIR system (Fourier-transform infrared) installed at the STP station, and an overview of techniques used for the CO2, CH4, and N2O retrievals. Trends of key greenhouse gases and their confidence levels were evaluated using an original approach which combines the Lomb–Scargle method with the cross-validation and bootstrapping techniques. As a result, the following fourteen-year (2009–2022) trends of TCs have been revealed: (0.56 ± 0.01) % yr−1 for CO2; (0.46 ± 0.02) % yr−1 for CH4; (0.28 ± 0.01) % yr−1 for N2O. A comparison with trends based on the EMAC numerical modeling data was carried out. The trends of greenhouse gases observed at the STP site are consistent with the results of the in situ monitoring performed at the same geographical location, and with the independent estimates of the global volume mixing ratio growth rates obtained by the GAW network and the NOAA Global Monitoring Laboratory. There is reasonable agreement between the CH4 and N2O TC trends for 2009–2019, which have been derived from FTIR measurements at three locations: the STP site, Izaña Observatory and the University of Toronto Atmospheric Observatory. [ABSTRACT FROM AUTHOR]

The application of nanocomposite fertilisers represents a progressive stride towards harmonising agronomical techniques with environmental conservation. Many studies have been embarked upon to gauge the effectiveness of fertilisers, engaging various substances encompassing polymers, clay minerals, and an amalgamation of synthetic and natural elements. Among these, using clay minerals, such as glauconite, which are both economical and readily accessible, provides an attractive substitute for numerous artificial substances. Glauconite is an adept inhibitor, consisting of nano and micro-particles with vast specific surface areas that maintain surface charge and provide ion-available interlayer sites, thus facilitating nutrient interchange. This study explores constructing and using nanocomposite fertilisers from glauconite amalgamated with a carbamide solution-gel. The ensuing nanocomposite exhibits enhanced intercalation between ammonium and glauconite, as substantiated by extensive analyses using techniques such as XRD, TEM, FTIR, TG-DSC, SEM-EDS, Brunauer-Emmett-Teller (BET) analysis, soil leaching experiments, lab and field agricultural tests. The mineral nanocomposites, replete with an assortment of novel functionalities, disclose that 20% of the carbamide solution results in an escalation of the intercalated N ratio to 8, predominantly within the smectite layers of glauconite. The decrease of a specific surface, the total pore volume and the average pore size in the nanocomposite reflects the adsorption of carbamide substances within the meso- and macropores of glauconite particles. The chemically synthesised glauconite nanocomposite retains an original spherical morphology, accompanied by a distinctive microlayer near the surface, and exhibits an increased nitrogen ratio, indicative of a superior filtration capability. Controlled-action nitrogen and potassium nanocomposite fertiliser were realised using glauconite as an inhibitor. The expectation of targeted and controlled release of nutrients such as ammonium, nitrate and potassium is facilitated by their multifarious forms within the glauconite. Chemically tailored glauconite nanocomposite confers numerous benefits, including a micro-granular mineral structure, a permeable internal morphology, the encapsulation of N compounds within diverse pore structures, and accessible potassium. Such characteristics of the nanocomposite aid in invigorating plant growth and development when these fertilisers are dispensed onto the soil. [ABSTRACT FROM AUTHOR]