Laser Photoacoustic Detection of CO2 in Old Disc Tree-Rings

Sensors

Boris Ageev¹  Yurii Ponomarev¹ 

[1] Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Sciences, Academician Zuev Square, 1. Tomsk, 634055, Russia;

关键词: laser photoacoustic gas analysis;    carbon dioxide;    tree-rings;    H₂O;   

DOI  :  10.3390/s100403305

来源: mdpi

【 摘 要 】

A homemade CO₂–laser photoacoustic spectrometer has been used for monitoring CO₂ in gas samples extracted under vacuum from the wood of old spruce disc tree-rings for a ∼60 year series. The experimental results show that (1) the CO₂ concentration exhibits annual trends correlated with an increase in atmospheric CO₂ in a number of cases; (2) at the time when the annual CO₂ trend changes from positive to negative, the annual tree-ring stable carbon isotope ratios (δ¹³C) of CO₂ change as well; (3) the disc tree-ring widths are observed to decrease in most cases where the annual CO₂ increased; (4) simultaneously with the annual CO₂ variation, annual H₂O distribution was detected in gas samples of the wood tree-rings of one spruce disc. The observed patterns of the annual CO₂ distribution in the disc tree-rings are assumed to be the evidence of the impact of the atmospheric CO₂ increase. In other words, a change in the concentration gradient between the stem and the atmospheric CO₂ may lead to a gradual CO₂ accumulation in the stem because of a decrease in the diffusion rate and to a change in the tree parameters.

【 授权许可】

CC BY   
© 2010 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland.