Towards understanding the variability in biospheric CO2 fluxes: using FTIR spectrometry and a chemical transport model to investigate the sources and sinks of carbonyl sulfide and its link to CO2
Item
Title (Dublin Core)
Towards understanding the variability in biospheric CO2 fluxes: using FTIR spectrometry and a chemical transport model to investigate the sources and sinks of carbonyl sulfide and its link to CO2
Description (Dublin Core)
Understanding carbon dioxide (CO<sub>2</sub>) biospheric processes is of great importance because the terrestrial exchange drives the seasonal and interannual variability of CO<sub>2</sub> in the atmosphere. Atmospheric inversions based on CO<sub>2</sub> concentration measurements alone can only determine net biosphere fluxes, but not differentiate between photosynthesis (uptake) and respiration (production). Carbonyl sulfide (OCS) could provide an important additional constraint: it is also taken up by plants during photosynthesis but not emitted during respiration, and therefore is a potential means to differentiate between these processes. Solar absorption Fourier Transform InfraRed (FTIR) spectrometry allows for the retrievals of the atmospheric concentrations of both CO<sub>2</sub> and OCS from measured solar absorption spectra. Here, we investigate co-located and quasi-simultaneous FTIR measurements of OCS and CO<sub>2</sub> performed at five selected sites located in the Northern Hemisphere. These measurements are compared to simulations of OCS and CO<sub>2</sub> using a chemical transport model (GEOS-Chem). The coupled biospheric fluxes of OCS and CO<sub>2</sub> from the simple biosphere model (SiB) are used in the study. The CO<sub>2</sub> simulation with SiB fluxes agrees with the measurements well, while the OCS simulation reproduced a weaker drawdown than FTIR measurements at selected sites, and a smaller latitudinal gradient in the Northern Hemisphere during growing season when comparing with HIPPO (HIAPER Pole-to-Pole Observations) data spanning both hemispheres. An offset in the timing of the seasonal cycle minimum between SiB simulation and measurements is also seen. Using OCS as a photosynthesis proxy can help to understand how the biospheric processes are reproduced in models and to further understand the carbon cycle in the real world.
Creator (Dublin Core)
Wang, Yuting
Deutscher, Nicholas M.
Palm, Mathias
Warneke, Thorsten
Notholt, Justus
Baker, Ian
Berry, Joe
Suntharalingam, Parvadha
Jones, Nicholas
Mahieu, Emmanuel
Lejeune, Bernard
Hannigan, James
Conway, Stephanie
Mendonca, Joseph
Strong, Kimberly
Campbell, J. Elliott
Wolf, Adam
Kremser, Stefanie
Date (Dublin Core)
2018-09-07
Type (Dublin Core)
Text
Format (Dublin Core)
application/pdf
Identifier (Dublin Core)
10.5194/acp-16-2123-2016
https://acp.copernicus.org/articles/16/2123/2016/
Source (Dublin Core)
eISSN: 1680-7324
Language (Dublin Core)
eng
