Fluxes of Atmospheric Greenhouse-Gases in Maryland (FLAGG-MD): Emissions of Carbon Dioxide in the Baltimore, MD-Washington, D.C. area

D Y Ahn; J R Hansford; S T Howe; X R Ren; R J Salawitch; N Zeng; M D Cohen; B Stunder; O E Salmon; P B Shepson; K R Gurney; T Oda; I Lopez-Coto; J Whetstone; R R Dickerson

Fluxes of Atmospheric Greenhouse-Gases in Maryland (FLAGG-MD): Emissions of Carbon Dioxide in the Baltimore, MD-Washington, D.C. area

J Geophys Res Atmos. 2020;125(9):https://doi.org/10.1029/2019jd032004.

Authors

D Y Ahn¹, J R Hansford², S T Howe³, X R Ren^{3

4

5}, R J Salawitch^{1

3

4}, N Zeng^{3

4}, M D Cohen⁵, B Stunder⁵, O E Salmon⁶, P B Shepson^{6

7}, K R Gurney⁸, T Oda^{9

10}, I Lopez-Coto¹¹, J Whetstone¹², R R Dickerson³

Affiliations

¹ Department of Chemistry and Biochemistry, University of Maryland College Park, Maryland, USA.
² Department of Computer Science, University of Maryland College Park, MD, USA.
³ Department of Atmospheric and Oceanic Science, University of Maryland College Park, MD, USA.
⁴ Earth System Science Interdisciplinary Center, University of Maryland College Park, MD, USA.
⁵ National Oceanic and Atmospheric Administration Air Resource Laboratory, College Park, MD, USA.
⁶ Department of Chemistry, Purdue University, West Lafayette, IN, USA.
⁷ School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY, USA.
⁸ School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, USA.
⁹ Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, MD, USA.
¹⁰ Goddard Earth Sciences Research and Technology, Universities Space Research Association, Columbia, MD, USA.
¹¹ Engineering Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA.
¹² Special Programs Office, National Institute of Standards and Technology, Gaithersburg, MD, USA.

PMID: 33094084
PMCID: PMC7577348

Abstract

To study emissions of CO₂ in the Baltimore, MD-Washington, D.C. (Balt-Wash) area, an aircraft campaign was conducted in February 2015, as part of the FLAGG-MD (Fluxes of Atmospheric Greenhouse-Gases in Maryland) project. During the campaign, elevated mole fractions of CO₂ were observed downwind of the urban center and local power plants. Upwind flight data and HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory) model analyses help account for the impact of emissions outside the Balt-Wash area. The accuracy, precision, and sensitivity of CO₂ emissions estimates based on the mass balance approach were assessed for both power plants and cities. Our estimates of CO₂ emissions from two local power plants agree well with their CEMS (Continuous Emissions Monitoring Systems) records. For the 16 power plant plumes captured by the aircraft, the mean percentage difference of CO₂ emissions was -0.3 %. For the Balt-Wash area as a whole, the 1σ CO₂ emission rate uncertainty for any individual aircraft-based mass balance approach experiment was ±38 %. Treating the mass balance experiments, which were repeated seven times within nine days, as individual quantifications of the Balt-Wash CO₂ emissions, the estimation uncertainty was ±16 % (standard error of the mean at 95% CL). Our aircraft-based estimate was compared to various bottom-up fossil fuel CO₂ (FFCO₂) emission inventories. Based on the FLAGG-MD aircraft observations, we estimate 1.9±0.3 MtC of FFCO₂ from the Balt-Wash area during the month of February 2015. The mean estimate of FFCO₂ from the four bottom-up models was 2.2±0.3 MtC.

Grants and funding

9999-NIST/ImNIST/Intramural NIST DOC/United States