Dynamics change in carbon cycle in contemporary environment in urban area in Gliwice, Poland

The primary aim of our study is to monitor carbon dioxide concentrations and carry out advanced analyses of the carbon cycle through mass spectrometry-based research in the biosphere within an urban environment in the southern region of Poland. Sampling sites within urban agglomerations are crucial for examining both the similarities and differences between urban areas, including the levels of CO₂ and their sources. Preliminary findings (Sensuła et al., 2023) suggest that continuous monitoring is essential, and incorporating additional research on carbon isotopes in the air may significantly contribute to understanding the carbon cycle in the studied areas.

In 2022, a new laboratory setup was established in Gliwice (Silesia, Poland) to monitor CO₂ levels, enabling precise measurement of CO₂ concentrations in the atmosphere. This system allows for high-time-resolution measurements of the CO₂ molar fraction, as well as the collection and analysis of air samples. Furthermore, the extraction of CO₂ from these samples, followed by ¹⁴C analysis via the MICADAS system, provides valuable data on the isotopic composition of both atmospheric and biospheric samples.

This study presents initial results in the form of a database documenting the molar fraction of CO₂ and ¹⁴CO₂ in atmospheric air samples from the urban area of Gliwice, Poland, covering the period from August 2023 to April 2025. CO₂ concentrations have been measured using a low-cost system (CARBOCAP GMP-343), while ¹⁴C concentrations were determined through the MICADAS technique. Our observations in 2024 indicate that the ¹⁴C values in the air samples ranged from -55‰ to -24‰, while the monthly CO₂ molar fraction varied between 428 and 469 ppm, depending on seasonal changes.

Additionally, since 2019 till 2024 we have investigated pine needles as potential archives of radiocarbon in contemporary environments. This examination focused on the radiocarbon concentration variations in pine needles of different ages, with thirty needle samples collected seasonally in Gliwice. The 14C concentrations in these samples were determined using a liquid scintillation counter, revealing a mean ¹⁴C fraction of 99.83 (69) pMC.

In January 2025, we began calibrating a new system based on the CRDS (cavity ring-down spectrometer) technique to analyze the stable isotopic composition of atmospheric gases (CO₂ and CH₄).

This work was supported by the following contracts and grants: the Initiative of Excellence – Research University programme implemented at the Silesian University of Technology, in the years 2022-2024 as part of a grant for cutting-edge research grant no.: 14/020 / SDU / 10-21- 03; project title: Analysis of CO₂ changes in the atmospheric air: construction of a new module to monitor CO2 concentration in the air; EU funds FSD - 10.25 Development of higher education focused on the needs of the green economy European Funds for Silesia 2021-2027 : The modern methods of
the monitoring of the level and isotopic composition of atmospheric CO₂ (project no.FESL.10.25-IZ.01-06C9/23-00) implemented at the Silesian University of Technology (2024-2026).