A013-01
A chemical data assimilation framework for utilizing data products from multiple platforms to optimize NMVOCs emissions in Northeast Asia: a case study during the KORUS-AQ

Monday, 7 December 2020: 05:32
Virtual
Jinkyul Choi1, Daven K Henze1, Hansen Cao1, Caroline R Nowlan2, Hyeong-Ahn Kwon3, Hyung-Min Lee4, Yujin Oak3, Rokjin Park4, Kelvin H Bates5, Joannes Maasakkers6, Jung-Hun Woo7, Jinseok Kim7, Alan Fried8, Donald Ray Blake9, Isobel J Simpson9, Andrew John Weinheimer10, William H Brune11, David A. W, Miller12 and James Szykman13, (1)University of Colorado Boulder, Boulder, CO, United States, (2)Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, United States, (3)Seoul National University, School of Earth and Environmental Sciences, Seoul, Korea, Republic of (South), (4)Seoul National University, School of Earth and Environmental Sciences, Seoul, South Korea, (5)Harvard University, School of Engineering and Applied Sciences, Cambridge, MA, United States, (6)Harvard University, Cambridge, MA, United States, (7)Konkuk University, Seoul, South Korea, (8)University of Colorado at Boulder, Institute of Arctic and Alpine Research, Boulder, CO, United States, (9)University of California Irvine, Irvine, CA, United States, (10)NCAR, Atmospheric Chemistry Observations and Modeling Laboratory, Boulder, CO, United States, (11)Pennsylvania State University, University Park, PA, United States, (12)Pennsylvania State University, Department of Ecosystem Science and Management, University Park, United States, (13)US EPA, ORD, National Exposure Research Laboratory, Hampton, VA, United States
Recorded Presentation
Abstract:
Simulated CH2O concentrations have been underestimated in recent years in Northeast Asia by a factor of two compared to satellite retrievals and aircraft observations. Here, we constrained formaldehyde sources, i.e., NMVOCs emissions, using satellite CH2O retrievals from OMI and OMPS and aircraft observations of CH2O and NMVOCs during the KORUS-AQ in May-June 2016. We developed and tested a framework that will allow us to perform long-term, high-resolution inversions using dense observations from recent and upcoming satellite missions such as Sentinel-5p, GEMS, TEMPO, and Sentinel-4. We first updated a 3-D chemical transport model, GEOS-Chem and its adjoint with the KORUSv5 anthropogenic emission inventory, optimized background CH4 fields, and the latest chemistry for aromatic species and C2H4. The updated model improved the O3simulations in terms of correlation against aircraft observations (from 0.3 to 0.6), while uncertainties in emissions caused a low bias of O3 (NMB ~ -0.2). To reduce these uncertainties, we developed a Hybrid Iterative Finite Difference Mass Balance (IFDMB) and 4D-Var inversion system (Hybrid IFDMB-4DVar). In this framework, we first quantified total NMVOCs emissions in a coarser horizontal resolution (2ºx2.5º) by using IFDMB with 3-years of oversampled OMI CH2O retrievals. We then conducted 4D-Var inversions with OMPS CH2O retrievals to optimize NMVOC speciation and to better account for transport and local chemistry in a nested horizontal resolution (0.25ºx0.3125º). To ensure the consistency of our inversions, we used aircraft CH2O observations to correct biases in satellite retrievals and to regularize the effects of each inversion. Finally, the aircraft observations of other NMVOCs were used to evaluate the posterior NMVOCs emissions. The total NMVOCs emissions throughout the domain were increased by about 50%. In some grid points, where anthropogenic emissions are high, the total NMVOCs emissions were increased by a factor of two to five, whereas some regions over Southeast Asia showed decreased biogenic emissions by a factor of two. The detailed NMVOC emission speciation and the impacts on the simulated O3 chemistry will be presented, as well as methodological considerations for future application of this framework using TROPOMI data and future geostationary instruments.
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