Kawa, Stephan (Randy): NASA GSFC (Project Lead)
Diskin, Glenn: NASA Langley Research Center (Co-Investigator)
Hanisco, Thomas: NASA GSFC (Co-Investigator)
Hurtt, George: University of Maryland (Co-Investigator)
Newman, Paul: NASA GSFC (Co-Investigator)
Wolfe, Glenn: NASA GSFC (Co-Investigator)
Collatz, George (Jim): NASA GSFC - retired (Collaborator)
Hannun, Reem: University of Pittsburgh (Participant)
Project Funding:
2016 - 2017
NRA: 2015 NASA: Carbon Monitoring System
Funded by NASA
Abstract:
Progress in the Carbon Monitoring System (CMS) demands rigorous evaluation and quantitative uncertainty characterization in all products and analyses. A range of validation approaches is used, but comprehensive evaluation is challenging, often limited
in coverage, representativeness, and precision. The guiding science question for this proposal is: how best to validate CMS regional-scale products and how well can this be done?
We aim to expand the current scope of validation methods for CMS through acquisition and analysis of airborne eddy covariance carbon flux observations. Specifically, we will address the question: How can real-time flux measurements over regional length scales contribute to validation of the products and processes inherent in designing a high- resolution Monitoring, Reporting, and Verification (MRV) system? We will do this within the framework of a prototype system for monitoring carbon stocks and fluxes under development for CMS at the University of Maryland (UMD).
Airborne eddy covariance is a powerful observational tool capable of providing near- direct measurements of surface-atmosphere exchange at ecosystem and policy relevant scales of 1 – 100 km. Our group at GSFC has assembled a system for measurement of CO2, CH4, H2O, and heat fluxes based on the NASA Sherpa aircraft. The Sherpa provides a versatile, economical platform for measuring greenhouse gas (GHG) fluxes to be used in evaluating top-down and bottom-up source/sink estimates for a wide range of applications, including evaluation of biophysical process models as well as validation of top-level satellite flux products from OCO-2 and other carbon space missions. The system is supported and scheduled for installation, flight-testing, and science demonstration over the Maryland Eastern Shore during July-Sept 2016.
To address uncertainties in the high-resolution MRV system we will focus on measuring and evaluating the ecosystem model processes used to connect vegetation metabolism to biomass change and, hence, integrated carbon flux. The analysis will compare flux data and modeling across gradients of forest height and type as well as soil and climate regime within the US Mid-Atlantic region. We will also use the airborne flux data to assess uncertainties in scaling up from local to regional and larger domains. This will include leveraging of the flux data acquired in 2016 under separate funding as well as acquisition of additional airborne flux data. The latter will be guided by sensitivities identified in the carbon stock and modeling surveys of the UMD prototype system. We will also assess the measurement requirements for airborne flux observations to quantify net carbon emissions and storage.
The impact of this project will be to advance the primary CMS goal of evaluation of errors and uncertainties by demonstrating a potentially powerful tool for flux quantification applicable to CMS. We will produce a data set of regional GHG flux estimates and their statistical errors for use in other CMS and community analyses, and we will provide a more comprehensive validation/evaluation of uncertainties in the UMD prototype MRV products. The measurement technique is also potentially applicable to validation for CMS Integrated Emission/Uptake (‘Flux’) products. This research directly addresses the CMS solicitation request to advance remote sensing-based approaches to MRV through use of airborne flux observations as an alternative method for quantifying net carbon emissions, and the need to improve the characterization and quantification of errors and uncertainties in existing NASA CMS products. The work is timely both for maturation of the MRV prototype system to include a better description of uncertainties as well as to make use of a new experimental capability for the corresponding domain.

Publications:
Hannun, R. A., Wolfe, G. M., Kawa, S. R., Hanisco, T. F., Newman, P. A., Alfieri, J. G., Barrick, J., Clark, K. L., DiGangi, J. P., Diskin, G. S., King, J., Kustas, W. P., Mitra, B., Noormets, A., Nowak, J. B., Thornhill, K. L., Vargas, R. 2020. Spatial heterogeneity in CO2, CH4, and energy fluxes: insights from airborne eddy covariance measurements over the Mid-Atlantic region. Environmental Research Letters. 15(3), 035008. DOI: 10.1088/1748-9326/ab7391
Wolfe, G. M., Kawa, S. R., Hanisco, T. F., Hannun, R. A., Newman, P. A., Swanson, A., Bailey, S., Barrick, J., Thornhill, K. L., Diskin, G., DiGangi, J., Nowak, J. B., Sorenson, C., Bland, G., Yungel, J. K., Swenson, C. A. 2018. The NASA Carbon Airborne Flux Experiment (CARAFE): instrumentation and methodology. Atmospheric Measurement Techniques. 11(3), 1757-1776. DOI: 10.5194/amt-11-1757-2018
More details may be found in the following project profile(s):
