Project Funding: 2016 - 2019

NRA: 2015 NASA: Carbon Monitoring System   

Funded by NASA

Abstract:
Despite the need to understand terrestrial biospheric carbon fluxes to account for carbon cycle feedbacks and predict future CO2 concentrations, knowledge of these fluxes at the regional scale remains poor. This is particularly true in mountainous areas, where complex atmospheric flows and relative lack of observations lead to significant uncertainties in carbon fluxes. Yet many mountainous regions also have significant forest cover and biomass—i.e., they are areas with the potential to serve as terrestrial carbon sinks. However, these sinks are highly dynamic and vulnerable to disturbance events, such as drought, insect damage, and wildfires. A strong need exists for the use of satellite remote sensing and modeling to help shed light on carbon dynamics in regions of complex terrain. Recent remote sensing advances from NASA can now be used to address the observational gap in mountainous areas. First, column-averaged CO2 (XCO2) yields atmospheric constraints on modeled biospheric fluxes in regions where in-situ CO2 observations are absent. Second, retrieval of Solar-Induced Fluorescence (SIF) from space has provided a powerful means to sense physiological signals of gross primary productivity (GPP) at regional to global scales. However, the relationship between SIF and GPP is complicated, and current uncertainties prevent scaling of well-established leaf-level fluorescence mechanisms to interpret GPP at larger scales, especially for coniferous species. Our proposed research will address the following key scientific questions: 1) How can satellite, atmospheric in-situ, and ecological observations be combined with atmospheric and biospheric models to inform carbon budgets in regions of complex terrain? 2) How is satellite-retrieved SIF related to leaf-level physiology? 3) What are the impacts of drought on carbon cycling in mountainous regions? We propose development and testing of a new Carbon Monitoring System over Mountains (CMS-Mountains) covering the Western U.S., where we will leverage numerous existing efforts in biospheric and atmospheric modeling. We will run the Community Land Model (CLM) at high spatial resolution, assimilating satellite observations of SIF, leaf area index, and snow cover within the Data Assimilation Research Testbed (DART). Signals of simulated biospheric fluxes from CLM-DART will be compared via atmospheric modeling to remotely sensed XCO2. Discrepancies will be minimized through adjustment of the regional fluxes as part of an atmospheric inversion. In this way, CMS-Mountains will deliver estimates of regional scale carbon fluxes over the Western U.S., along with their uncertainties, constrained by remotely sensed datasets. While the proposed project will focus on the Western U.S., the framework we develop will be applicable elsewhere. We anticipate the CMS-Mountains platform will ultimately be applied to other regions of complex terrain around the world, driven by remote sensing data in the absence of in-situ measurements. This project directly addresses the objectives of NASA’s CMS program, as mentioned in the proposal call. We are proposing a study that uses “remote sensing data products to produce and evaluate prototype MRV system approaches”. It will contribute towards “U.S. national efforts toward integrated carbon monitoring” by helping to constrain the U.S. carbon budget for a region that is poorly understood (Western U.S.). Moreover, our project will help “improve the characterization and quantification of errors and uncertainties in existing and/or proposed NASA CMS products” for regions of complex terrain. To our knowledge, existing CMS projects either have a global scope or focus on regions outside of mountainous areas. By focusing on the carbon budget in the Western U.S., an area of complex terrain, our project will help quantify the magnitude and sources of uncertainties in other CMS products over this area.

Publications:

Kannenberg, S. A., Bowling, D. R., Anderegg, W. R. L. 2020. Hot moments in ecosystem fluxes: High GPP anomalies exert outsized influence on the carbon cycle and are differentially driven by moisture availability across biomes. Environmental Research Letters. 15(5), 054004. DOI: 10.1088/1748-9326/ab7b97

Magney, T. S., Bowling, D. R., Logan, B. A., Grossmann, K., Stutz, J., Blanken, P. D., Burns, S. P., Cheng, R., Garcia, M. A., Kohler, P., Lopez, S., Parazoo, N. C., Raczka, B., Schimel, D., Frankenberg, C. 2019. Mechanistic evidence for tracking the seasonality of photosynthesis with solar-induced fluorescence. Proceedings of the National Academy of Sciences. 116(24), 11640-11645. DOI: 10.1073/pnas.1900278116

Peters, W., van der Velde, I. R., van Schaik, E., Miller, J. B., Ciais, P., Duarte, H. F., van der Laan-Luijkx, I. T., van der Molen, M. K., Scholze, M., Schaefer, K., Vidale, P. L., Verhoef, A., Warlind, D., Zhu, D., Tans, P. P., Vaughn, B., White, J. W. C. 2018. Increased water-use efficiency and reduced CO2 uptake by plants during droughts at a continental scale. Nature Geoscience. 11(10), 744-748. DOI: 10.1038/s41561-018-0212-7

Raczka, B., Hoar, T. J., Duarte, H. F., Fox, A. M., Anderson, J. L., Bowling, D. R., Lin, J. C. 2021. Improving CLM5.0 Biomass and Carbon Exchange Across the Western United States Using a Data Assimilation System. Journal of Advances in Modeling Earth Systems. 13(7). DOI: 10.1029/2020MS002421

Raczka, B., Porcar-Castell, A., Magney, T., Lee, J. E., Kohler, P., Frankenberg, C., Grossmann, K., Logan, B. A., Stutz, J., Blanken, P. D., Burns, S. P., Duarte, H., Yang, X., Lin, J. C., Bowling, D. R. 2019. Sustained Nonphotochemical Quenching Shapes the Seasonal Pattern of Solar-Induced Fluorescence at a High-Elevation Evergreen Forest. Journal of Geophysical Research: Biogeosciences. 124(7), 2005-2020. DOI: 10.1029/2018JG004883

Zuromski, L. M., Bowling, D. R., Kohler, P., Frankenberg, C., Goulden, M. L., Blanken, P. D., Lin, J. C. 2018. Solar-Induced Fluorescence Detects Interannual Variation in Gross Primary Production of Coniferous Forests in the Western United States. Geophysical Research Letters. 45(14), 7184-7193. DOI: 10.1029/2018GL077906

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