The use of OCS measured with FTIR spectrometry as a tracer for photosynthesis and respiration
Final Report Abstract
This is the first time that column measurements from FTIR networks are used to study the relationship between OCS and CO2. The objective is to test the application of OCS as a photosynthesis tracer, and to exploit the usage of FTIR measurements for this topic. The OCS columns are retrieved from the measured spectra at twelve stations spanning both Northern and Southern Hemisphere. The retrieved xOCS time series shows a clear seasonal cycle, which is similar to that of CO2. Forward simulations of OCS and CO2 were performed and compared with the measurements, and the current flux estimations were evaluated. Then the OCS flux inversions were conducted to obtain better flux maps from the atmospheric measurements. However, the validation with aircraft measurements shows mismatches in the tropics as well as in the northern temperate region, where the measurements are too sparse to constrain the fluxes. Inclusion of FTIR measurements does not improve the inversion, because there is an offset between these two data sets, which makes it difficult to use them simultaneously. After the flux evaluation, the use of OCS to study the carbon land cycles were tested. The CO2 biosphere fluxes in SiB were evaluated in the Northern Hemisphere with the help of OCS. It indicates that the individual fluxes of CO2 can be wrong even the net flux is reasonable. The FTIR OCS retrievals need to be calibrated using independent measurements to make them comparable with in-situ measurements. After that, the FTIR column data can be included into the flux inversion.
Publications
- Positive trends in Southern Hemisphere carbonyl sulfide, Geophys. Res. Lett., 42, 9473–9480
Kremser, S., Jones, N. B., Palm, M., Lejeune, B. Wang, Y., Smale, D., and Deutscher N. M.
(See online at https://doi.org/10.1002/2015GL065879) - Towards understanding the variability in biospheric CO 2 fluxes: using FTIR spectrometry and a chemical transport model to investigate the sources and sinks of carbonyl sulfide and its link to CO2, Atmos. Chem. Phys., 16, 2123-2138
Wang, Y., Deutscher, N. M., Palm, M., Warneke, T., Notholt, J., Baker, I., Berry, J., Suntharalingam, P., Jones, N., Mahieu, E., Lejeune, B., Hannigan, J., Conway, S., Mendonca, J., Strong, K., Campbell, J. E., Wolf, A., and Kremser, S.
(See online at https://doi.org/10.5194/acp-16-2123-2016) - Using ground-based FTIR column measurements to study OCS and its link to CO2. OCS workshop, Hyytiälä Forestry Field Station, Finland, September, 2016
Wang Y., Marshall J., Palm M., Deutscher N., Roedenbeck C., Warneke T., Baker I., Berry J., Suntharalingam P., Jones N., Mahieu E., Lejeune B., Hannigan J., Conway S., Strong K., Vigouroux C., Morino I., Campbell E., Wolf A., Kremser S., and Notholt J.
- Using NDACC column measurements of carbonyl sulfide to estimate its sources and sinks. PICO-presentation at EGU 2016, Vienna, Austria, April, 2016
Wang Y., Marshall J., Palm M., Deutscher N., Roedenbeck C., Warneke T., Notholt J., Baker I., Berry J., Suntharalingam P., Jones N., Mahieu E., Lejeune B., Hannigan J., Conway S., Strong K., Campbell E., Wolf A., and Kremser S.
- Using solar FTIR spectrometry to investigate the sources and sinks of carbonyl sulfide and its application to the carbon cycle, PhD-thesis, University of Bremen, Germany, 2016
Wang, Y.
