Project Funding: 2010 - 2014

Funded by NASA

Abstract:
As the need to quantify, monitor, and understand natural and anthropogenic fluxes of carbon dioxide (CO₂) has grown, remote sensing observations of CO₂ have increasingly been considered to be a critical element in the global CO2 monitoring network. These data will be used to verify emissions reductions in response to carbon policies, and to monitor the behavior of biospheric and oceanic CO₂ sinks in a changing climate. In these early days of the use of satellite observations for monitoring global CO₂, several fundamental questions need to be answered in order to reliably make use of the information content of available observations, and use these insights to inform planning for future missions. These questions include (i) assessing the impact on estimation precision and accuracy, relative to traditional “batch” inversions, of implementing the numerical data assimilation (DA) tools needed to utilize the volumes of data coming from satellites, (ii) improving understanding of the impact of specific transport models on flux estimates, (iii) quantifying the sensitivity of satellite observations to plausible differences between alternative flux scenarios, (iv) quantifying the degree to which a combination of in situ and satellite observations of CO₂ can constrain fossil fuel emissions, (v) determining the degree to which existing biospheric models can explain the observed variability in atmospheric CO₂, and what additional environmental variables explain the remaining variability, and (vi) quantifying the degree to which satellite observations of CO₂ affect estimates of fluxes. We propose to begin to address each of these questions by focusing on two existing instruments, AIRS and GOSAT, with the North American (NA) continent as a testing ground. The overall objectives of this project are to (1) Build the infrastructure required to incorporate in situ and satellite observations of CO₂ for constraining biospheric and anthropogenic NA fluxes of CO₂; (2) Evaluate and quantify the benefit of GOSAT and AIRS CO₂ data for informing improvements to flux estimates and atmospheric transport models; and (3) Disseminate results to researchers, decision makers, and the public through web browser-based and virtual globe applications.

Publications:

Shiga, Y. P., Michalak, A. M., Fang, Y., Schaefer, K., Andrews, A. E., Huntzinger, D. H., Schwalm, C. R., Thoning, K., Wei, Y. 2018. Forests dominate the interannual variability of the North American carbon sink. Environmental Research Letters. 13(8), 084015. DOI: 10.1088/1748-9326/aad505

Shiga, Y. P., Tadic, J. M., Qiu, X., Yadav, V., Andrews, A. E., Berry, J. A., Michalak, A. M. 2018. Atmospheric CO 2 Observations Reveal Strong Correlation Between Regional Net Biospheric Carbon Uptake and Solar-Induced Chlorophyll Fluorescence. Geophysical Research Letters. 45(2), 1122-1132. DOI: 10.1002/2017GL076630

Tadic, J. M., Michalak, A. M. 2016. On the effect of spatial variability and support on validation of remote sensing observations of CO2. Atmospheric Environment. 132, 309-316. DOI: 10.1016/j.atmosenv.2016.03.014

Fang, Y., Michalak, A. M. 2015. Atmospheric observations inform CO2flux responses to enviroclimatic drivers. Global Biogeochemical Cycles. 29(5), 555-566. DOI: 10.1002/2014GB005034

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

• North American Carbon Program (NACP) Project Profile