Project Funding: 2013 - 2017

NRA: 2013 NASA: Carbon Monitoring System   

Funded by NASA

Abstract:
Uncertainty in atmospheric transport and a lack of atmospheric carbon dioxide (CO2) observations are the two major sources of uncertainty in inverse estimates of CO2 sources and sinks. Space-based measurements of atmospheric CO2 will greatly increase the density of atmospheric measurements. Atmospheric transport, however, remains a major challenge. We propose to improve our understanding of the uncertainties associated with atmospheric transport in the NASA Carbon Monitoring System Flux estimation and attribution pilot project (CMS Flux). This project will focus on uncertainties at the regional to continental scale, focusing in particular on North America for calendar year 2010. The results should be applicable to any mid-latitude continental region. We will: 1) assess the transport error in the global NASA CMS-Flux system and the mesoscale WRF-LPDM using meteorological data and CO2 profiles from airborne measurements over North America; 2) represent transport error with a physics-based ensemble of atmospheric transport configurations; and 3) estimate the contribution of transport uncertainty over North America to North American and global flux uncertainty. This proposal will address the request in the NASA CMS announcement of opportunity for, 'Studies to improve the characterization and quantification of errors and uncertainties in existing and/or proposed NASA CMS products, including errors and uncertainties in the algorithms, models, and associated methodologies utilized in creating them.' We will evaluate the impact of atmospheric transport on the CMS Flux pilot products by embedding the Penn State regional atmospheric inversion system, which utilizes the mesoscale Weather Research and Forecast model (WRF), within the CMS Flux system, by simulating atmospheric CO2 and solving for continental fluxes with both systems, and by evaluating transport uncertainty by comparing the CMS Flux system output to meteorological observations and aircraft CO2 profile data. The first objective will be met by simulating the atmospheric distribution of CO2 across North America with both WRF and Geos-Chem (the CMS Flux atmospheric transport scheme). Both simulations will use the same lateral boundary conditions and surface fluxes. Meteorological observations will be used to quantify the atmospheric transport uncertainty in CMS Flux. Aircraft CO2 profiles will be used to quantify the model-data mismatch error used in CMS Flux inversions. The second objective will be met by running a physics-based ensemble of WRF simulations conditioned to match the range of transport errors found in the CMS Flux system by comparison to meteorological observations. This ensemble will be sampled to simulated GOSAT and OCO-2 observational patterns. This produces a set of column CO2 pseudo-data with a distribution similar to the CMS Flux transport error. The third objective will be addressed by using this ensemble of simulated satellite observations to infer an ensemble of fluxes using the CMS Flux system. The differences among the inferred fluxes should be a realistic representation of atmospheric transport error in the CMS Flux biogenic flux product.

Publications:

Butler, M. P., Lauvaux, T., Feng, S., Liu, J., Bowman, K. W., Davis, K. J. 2020. Atmospheric Simulations of Total Column CO2 Mole Fractions from Global to Mesoscale within the Carbon Monitoring System Flux Inversion Framework. Atmosphere. 11(8), 787. DOI: 10.3390/atmos11080787

Butler, M. P., Lauvaux, T., Feng, S., Liu, J., Bowman, K. W., Davis, K. J. Mass-conserving coupling of total column CO<sub>2</sub> (XCO<sub>2</sub>) from global to mesoscale models: Case study with CMS-Flux inversion system and WRF-Chem (v3.6.1) DOI: 10.5194/gmd-2018-342

Diaz-Isaac, L. I., Lauvaux, T., Bocquet, M., Davis, K. J. 2019. Calibration of a multi-physics ensemble for estimating the uncertainty of a greenhouse gas atmospheric transport model. Atmospheric Chemistry and Physics. 19(8), 5695-5718. DOI: 10.5194/acp-19-5695-2019

Diaz-Isaac, L. I., Lauvaux, T., Davis, K. J. 2018. Impact of physical parameterizations and initial conditions on simulated atmospheric transport and CO<sub>2</sub> mole fractions in the US Midwest. Atmospheric Chemistry and Physics. 18(20), 14813-14835. DOI: 10.5194/acp-18-14813-2018

Liu, J., Bowman, K. W., Henze, D. K. 2015. Source-receptor relationships of column-average CO2and implications for the impact of observations on flux inversions. Journal of Geophysical Research: Atmospheres. 120(10), 5214-5236. DOI: 10.1002/2014JD022914

Liu, J., Bowman, K. W., Lee, M., Henze, D. K., Bousserez, N., Brix, H., James Collatz, G., Menemenlis, D., Ott, L., Pawson, S., Jones, D., Nassar, R. 2014. Carbon monitoring system flux estimation and attribution: impact of ACOS-GOSAT XCO2 sampling on the inference of terrestrial biospheric sources and sinks. Tellus B: Chemical and Physical Meteorology. 66(1), 22486. DOI: 10.3402/tellusb.v66.22486

Liu, J., Bowman, K., Parazoo, N. C., Bloom, A. A., Wunch, D., Jiang, Z., Gurney, K. R., Schimel, D. 2018. Detecting drought impact on terrestrial biosphere carbon fluxes over contiguous US with satellite observations. Environmental Research Letters. 13(9), 095003. DOI: 10.1088/1748-9326/aad5ef

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

• North American Carbon Program (NACP) Project Profile
• NASA Carbon Monitoring System (CMS) Project Profile