Interpreting the 13C/12C ratio of carbon dioxide in an urban airshed in the Yangtze River Delta, China
Authors:
Preprint
- 9 May 2016
- preprint
- Published by Copernicus GmbH in EGUsphere
- Vol. 2016, 1-42
Abstract
Observations of atmospheric CO2 molar fraction and its 13C isotope composition (δ13C) in urban airsheds provide constraints on the roles of anthropogenic and natural sources in local and regional C cycles. In this study, we report observations of these quantities in Nanjing at hourly intervals from March 2013 to August 2015 using a laser-based optical instrument. Nanjing is the second largest city located in the highly industrialized Yangtze River Delta (YRD), Eastern China. The mean CO2 molar fraction and 13C were 439.7 ppm and −8.48 ‰ over this observational period. The peak monthly mean δ13C (−7.44 ‰, July 2013) was 1.03 ‰ higher than that observed at the Mauna Loa Observatory. The highly enriched 13C signal was attributed to the influence of cement production in the region. By applying the Keeling plot and the Miller–Tans method to midnight and midday observations, respectively, we showed that the 13C signal of C sources in the Nanjing Municipality was 0.48 ‰ lower than that in the YRD. Flux partitioning calculations revealed that natural ecosystems in the YRD were a negligibly small sink of atmospheric CO2, consistent with the Carbon Tracker inverse modeling result.Keywords
All Related Versions
- Published version: Atmospheric Chemistry and Physics, 17 (5), 3385.
This publication has 58 references indexed in Scilit:
- Tracing the flow of carbon dioxide and water vapor between the biosphere and atmosphere: A review of optical isotope techniques and their applicationAgricultural and Forest Meteorology, 2013
- Analysis of China's carbon dioxide flow for 2008Energy Policy, 2013
- Drivers of spatial variability in urban plant and soil isotopic composition in the Los Angeles basinPlant and Soil, 2011
- An integrated approach to improving fossil fuel emissions scenarios with urban ecosystem studiesEcological Complexity, 2009
- Global cooling: increasing world-wide urban albedos to offset CO2Climatic Change, 2008
- Inferring biogenic and anthropogenic carbon dioxide sources across an urban to rural gradientOecologia, 2007
- Feasibility of quantifying ecosystem–atmosphere C18O16O exchange using laser spectroscopy and the flux-gradient methodAgricultural and Forest Meteorology, 2005
- The use of stable isotopes to study ecosystem gas exchangeOecologia, 2000
- The concentration and isotopic abundances of carbon dioxide in rural and marine airGeochimica et Cosmochimica Acta, 1961
- The concentration and isotopic abundances of atmospheric carbon dioxide in rural areasGeochimica et Cosmochimica Acta, 1958