Elemental analysis of biogeochemical archives is an established technique used to study climate in a range of applications, including ocean circulation, glacial/interglacial climates, and anthropogenic climate change. Data from mollusc archives are especially important because of their global abundance and sub-annual resolution. Despite this potential, they are underrepresented among palaeoclimate studies, due to enigmatic physiological influences skewing the elemental record. Understanding the patterns behind these influences will improve data interpretation and lead to the development of new climate proxies. Here, we show for the first time that extensive spatial mapping of multiple mollusc specimens using Laser Induced Breakdown Spectroscopy (LIBS) across a wider region can resolve enigmatic patterns within the elemental record caused by physiological influences. 2D elemental (Mg/Ca) maps of whole limpet shells (Patella caerulea) from across the Mediterranean revealed patterns of variability within individual mollusc records as well as within isochronous parts of specimens. By registering and quantifying these patterns, we established previously uninterpretable correlations with temperature (R² > 0.8, p < 0.01). This outcome redefines the possibilities of accessing sub-annual climate proxies and presents the means to assess annual temperature ranges using oxygen isotope analysis requiring only 2 samples per shell.

A ground-based, integrated path, differential absorption (IPDA) light detection device capable of measuring multiple greenhouse gas (GHG) species in the atmosphere is presented. The device was developed to monitor greenhouse gas concentrations in small-scale areas with high emission activities. It is equipped with two low optical power tunable diode lasers in the near-infrared spectral range for the atmospheric detection of carbon dioxide, methane, and water vapors (CO₂, CH₄ and H₂O). The device was tested with measurements of background concentrations of CO₂ and CH₄ in the atmosphere (Crete, Greece). Accuracies in the measurement retrievals of CO₂ and CH₄ were estimated at 5 ppm (1.2%) and 50 ppb (2.6%), respectively. A method that exploits the intensity of the recorded H₂O absorption line in combination with weather measurements (water vapor pressure, temperature, and atmospheric pressure) to calculate the GHG concentrations is proposed. The method eliminates the requirement for measuring the range of the laser beam propagation. Accuracy in the measurement of CH₄ using the H₂O absorption line is estimated at 90 ppb (4.8%). The values calculated by the proposed method are in agreement with those obtained from the differential absorption LiDAR equation (DIAL).

The interaction of 1-iodopropane, 2-iodopropane, 1-iodobutane, 2-iodobutane, and 1-iodopentane with (5 × 10^13-5 × 10¹⁵ W/cm²) femtosecond laser fields is studied by means of a time-of-flight mass spectrometer. It is found that multiphoton ionization (MPI) and field ionization (FI) processes are involved in the molecular ionization. The contribution of these processes can be distinguished using the peak profile of the ions in the mass spectra. Thus, from the mass spectra of 2-iodoropane and 2-iodobutane, it is concluded that MPI processes are taking place even for Keldysh parameter values γ ∼ 0.3. The field ionization process depends on the characteristics of the molecular binding potential well and leads to an asymmetric charge distribution of the transient multiply charged parent ions. In the case of 1-iodobutane, the MPI processes lead to a stable doubly charged parent ion production with a laser intensity threshold higher than that found for I²⁺ ions. In addition, the isomers studied exhibit distinct differences in their mass spectra and their origin is discussed in detail.

The technical specifications and the evaluation of the remote operation of the open-path, tunable diode laser absorption spectroscopic (TDLAS) instrument are presented. The instrument is equipped with two low optical power diode lasers in the near-infrared spectral range for the atmospheric detection of carbon dioxide, methane, and water vapors (CO₂, CH_4, and H₂O). Additionally, the instrument eliminates the requirement of retroreflectors since it detects the back reflection of the laser beam from any topographic target. The instrument was operated remotely by measuring background concentrations of CO₂ and CH₄ in the atmosphere from 24 November 2022 to 4 January 2023. The accuracy of CO₂ and CH₄ measurement retrievals on a 200 m laser path was estimated at 20 ppm (4.8%) and 60 ppb (3.1%), respectively. The CH₄ accuracy is comparable, but the CO₂ accuracy is noticeably lower than the accuracy achieved in local operation. The accuracy issues raised are studied and discussed in terms of the laser driver’s cooling performance.

In this study, we introduce a simple but effective model, combined with a classification system for light sources based on their spectral profile approximated by the relative power distribution in the red, green and blue regions, which successfully fits experimental data of pigment colour changes in an oil binder under various lighting conditions. This model is experimentally validated by artificial ageing tests on two sets of model samples made of historical pigments (strontium yellow and Prussian blue mixed with lead white) using three white light sources (two WLEDs and a xenon light source). The model accurately fits colour shifts by analysing changes in International Commission on Illumination L*a*b* values. The results highlight that integrating the spectral classification of the light sources with the colour change model provides deeper insights into the causes of paint colour changes than traditional methods that rely solely on total irradiance. This combined approach enables precise prediction of long-term colour changes by exploiting the spectral characteristics of light sources.