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Funded Research

Quantifying Changes in the Distribution and Cycling of Carbon With Total Column Measurements of CO2 and CH4

Wennberg, Paul: Caltech (Project Lead)
Baker, David: Colorado State University (Participant)
Chevallier, Frederic: (Participant)
Deutscher, Nicholas: U. Wollongong (Participant)
Griffith, David: U. Wollongong (Participant)
Iraci, Laura: NASA Ames Research Center (Participant)
Sweeney, Colm: NOAA Earth System Research Laboratory (Participant)
Toon, Geoffrey: JPL (Participant)
Wofsy, Steven (Steve): Harvard University (Participant)
Wunch, Debra: University of Toronto (Participant)

Project Funding: 2014 - 2017

NRA: 2013 NASA: Carbon Cycle Science   

Funded by NASA

NASA's Carbon Cycle Program has historically supported the development of the Total Carbon Column Observing Network (TCCON). Here, we propose to continue to support the coordination, maintenance, and analysis of long-term measurements from the network. There are currently 20 operational TCCON sites; 4 additional sites will produce data in the near future. All PIs of existing sites are participants in this proposal. TCCON is both scientifically and societally important. Data from the network are being used extensively (>50 peer-reviewed publications in the last 3 years) to improve the description of carbon dynamics and to help evaluate products developed from space-based sensors. The network is highly responsive to the proposal call for Carbon Cycle Science: TCCON observes atmospheric column abundances of CO2, CH4, CO and other species in tropical terrestrial ecosystems (3.1.1, Reunion Island, Ascension Island, Darwin, and the future Manaus station), the arctic and Boreal regions (3.1.2, Eureka, Ny Alesund, Sodankyla, Park Falls, Bialystok, Orleans, Karlsruhe), as well as in urban (3.4, Caltech, Bremen, Wollongong), and background regions (Lauder, Izana). The proposed work directly addresses the critical need identified in 3.7.2, cross-cutting research activities, to provide a critical and continual evaluation of space-based data for atmospheric CO2 and CH4. TCCON provides the primary validation data for multiple existing and future US and foreign missions. TCCON is a critical source of validation data for GOSAT; for OCO-2 (launch July 2014); OCO-3; for ASCENDS. TCCON has been used in the evaluation of SCIAMACHY and MOPITT data, and is planned for use in GOSAT-2 and S-5P. More than 25 peer-reviewed publications describe validation of such products with TCCON data. We propose to use TCCON and other data sets to investigate the underlying fluxes of carbon to and from the atmosphere. Through key collaborations with members of the carbon cycle community, we will investigate variability in the flux of CO2 and CH4 using observations made from TCCON and associated data sets made by remote sensing from space. We will use both large-scale modeling tools (e.g. global chemical transport models with underlying biochemistry) and tracer-tracer approaches to improve estimation of the underlying fluxes. The focus of these analyses will be on improving the description of large-scale terrestrial carbon dynamics at northern high latitudes. Proposed Work Plan 1. Continue operations of the Park Falls, Wisconsin TCCON site. 2. Continue coordination of the broader network activities. Continue data evaluation using profiles obtained from AirCore and Aircraft. 3. Assist in the use of TCCON data for evaluation of space-based data for CO2 and CH4. 4. Extend the spectral coverage of several TCCON sites to enable retrieval of HCN (biomass burning tracer), ethane (tracer of emissions from fossil fuel extraction), and OCS (tracer of photosynthesis). 5. Investigate use of TCCON and other data sets to improve process-level understanding of carbon flux between the land, ocean, and atmosphere. a. Long-term records now provide key constraints on interannual variability in CO2. We will continue to develop new tools and approaches for constraining the large-scale flux patterns and their variability, with a focus on boreal latitudes. b. The development of highly precise and accurate total and tropospheric CH4 column measurements enable analysis of the role of chemistry, dynamics, and source variability in determining the temporal and spatial patterns of CH4. We will undertake a broad investigation of atmospheric methane dynamics to evaluate how the sources and sinks are manifest in the variability of the total column.


Hedelius, J. K., Feng, S., Roehl, C. M., Wunch, D., Hillyard, P. W., Podolske, J. R., Iraci, L. T., Patarasuk, R., Rao, P., O'Keeffe, D., Gurney, K. R., Lauvaux, T., Wennberg, P. O. 2017. Emissions and topographic effects on column CO2 ( XCO2) variations, with a focus on the Southern California Megacity. Journal of Geophysical Research: Atmospheres. 122(13), 7200-7215. DOI: 10.1002/2017JD026455

Hedelius, J. K., Liu, J., Oda, T., Maksyutov, S., Roehl, C. M., Iraci, L. T., Podolske, J. R., Hillyard, P. W., Liang, J., Gurney, K. R., Wunch, D., Wennberg, P. O. 2018. Southern California megacity CO2, CH4, and CO flux estimates using ground- and space-based remote sensing and a Lagrangian model. Atmospheric Chemistry and Physics. 18(22), 16271-16291. DOI: 10.5194/acp-18-16271-2018

Hedelius, J. K., Parker, H., Wunch, D., Roehl, C. M., Viatte, C., Newman, S., Toon, G. C., Podolske, J. R., Hillyard, P. W., Iraci, L. T., Dubey, M. K., Wennberg, P. O. 2017. Intercomparability of XCO2 and XCH4 from the United States TCCON sites. Atmospheric Measurement Techniques. 10(4), 1481-1493. DOI: 10.5194/amt-10-1481-2017

Hedelius, J. K., Viatte, C., Wunch, D., Roehl, C. M., Toon, G. C., Chen, J., Jones, T., Wofsy, S. C., Franklin, J. E., Parker, H., Dubey, M. K., Wennberg, P. O. 2016. Assessment of errors and biases in retrievals of XCO2, XCH4, XCO, and XN2O from a 0.5 cm1 resolution solar-viewing spectrometer. Atmospheric Measurement Techniques. 9(8), 3527-3546. DOI: 10.5194/amt-9-3527-2016

Stavros, E. N., Schimel, D., Pavlick, R., Serbin, S., Swann, A., Duncanson, L., Fisher, J. B., Fassnacht, F., Ustin, S., Dubayah, R., Schweiger, A., Wennberg, P. 2017. ISS observations offer insights into plant function. Nature Ecology & Evolution. 1(7), 0194. DOI: 10.1038/s41559-017-0194

Wang, Z., Warneke, T., Deutscher, N. M., Notholt, J., Karstens, U., Saunois, M., Schneider, M., Sussmann, R., Sembhi, H., Griffith, D. W. T., Pollard, D. F., Kivi, R., Petri, C., Velazco, V. A., Ramonet, M., Chen, H. 2017. Contributions of the troposphere and stratosphere to CH4 model biases. Atmospheric Chemistry and Physics. 17(21), 13283-13295. DOI: 10.5194/acp-17-13283-2017

Wunch, D., Wennberg, P. O., Osterman, G., Fisher, B., Naylor, B., Roehl, C. M., O'Dell, C., Mandrake, L., Viatte, C., Kiel, M., Griffith, D. W. T., Deutscher, N. M., Velazco, V. A., Notholt, J., Warneke, T., Petri, C., De Maziere, M., Sha, M. K., Sussmann, R., Rettinger, M., Pollard, D., Robinson, J., Morino, I., Uchino, O., Hase, F., Blumenstock, T., Feist, D. G., Arnold, S. G., Strong, K., Mendonca, J., Kivi, R., Heikkinen, P., Iraci, L., Podolske, J., Hillyard, P. W., Kawakami, S., Dubey, M. K., Parker, H. A., Sepulveda, E., Garcia, O. E., Te, Y., Jeseck, P., Gunson, M. R., Crisp, D., Eldering, A. 2017. Comparisons of the Orbiting Carbon Observatory-2 (OCO-2) XCO2 measurements with TCCON. Atmospheric Measurement Techniques. 10(6), 2209-2238. DOI: 10.5194/amt-10-2209-2017

Saad, K. M., Wunch, D., Toon, G. C., Bernath, P., Boone, C., Connor, B., Deutscher, N. M., Griffith, D. W. T., Kivi, R., Notholt, J., Roehl, C., Schneider, M., Sherlock, V., Wennberg, P. O. 2014. Derivation of tropospheric methane from TCCON CH4 and HF total column observations. Atmospheric Measurement Techniques. 7(9), 2907-2918. DOI: 10.5194/amt-7-2907-2014

2015 NASA Carbon Cycle & Ecosystems Joint Science Workshop Poster(s)

  • Using Atmospheric Column Measurements to Estimate the Impact of Climate Variables on CO2 Uptake by the Biosphere   --   (Debra Wunch, Paul Wennberg, William Simpson, Geoffrey C. Toon, Nick Parazoo, Arlyn Elizabeth Andrews, Dylan Jones, Coleen Marie Roehl, Kimberly Strong, Ray Nassar)   [abstract]

More details may be found in the following project profile(s):