Project Funding: 2014 - 2018

NRA: 2014 NASA: OCO-2 Science Team for the OCO-2 Mission   

Funded by NASA

Abstract:
OCO-2’s primary goal is to make global CO2 observations to improve our understanding of processes controlling emissions and uptake of carbon. Increasing CO2 levels, which are directly attributable to anthropogenic emissions, drives the heightened interest and concern in climate. As global emissions increase, and continue to grow even more so in the developing world, our knowledge of anthropogenic input becomes more uncertain. This is degrading our ability to interpret variability as indicative of ecosystem feedbacks, and preventing us from determining what emissions and climate trajectory we are on. We propose to build upon our pioneering work with the Greenhouse gas Observing SATellite (GOSAT) to provide a crucial observational constraint on anthropogenic emissions and emissions changes by focusing on global megacities. We focus on global megacities, as urban regions are now estimated to contribute over 70% of global anthropogenic carbon emissions. The geographic confinement of this large portion of emissions also presents an observational benefit, as large and distinct urban CO2 signatures can be observed from space and monitored over time (as we have demonstrated with GOSAT). In this proposed work we will take a tiered approach. First, we will focus on four megacities: Los Angeles, London, Paris, and Tokyo. In each of these cities we will perform high-resolution (1.33 Km) simulations to link atmospheric concentration to emissions. We will use the Open-source Data Inventory for Anthropogenic CO2 (ODIAC) for prior emissions. We then will perform inversions using OCO-2 observations to update/improve the ODIAC inventory. Each of these cities was chosen due to the presence of ground observations made in each city, and we have engaged with collaborators for each network to ensure we can use their ground-based network in conjunction with the OCO-2 data to provide robust validation. We will also extend a data-based analysis technique (no transport model) for quantifying emissions and trendswe will test this method in these cities of focused study, and then extend to a dozen cities worldwide-providing a more global observational constraint on anthropogenic emissions. In each city we will consider nadir and glint-mode observations-rigorously assessing the consistency of the observing modes in locations with large CO2 gradients and potentially high aerosol loading. Finally, we will perform regional modeling to link the urban emission to continental scales. This will enable us to inform the broader OCO-2 science team on the impact of megacities on the global OCO-2 observations and inversions, and the impact of upwind sources on megacity observations. Our proposal team brings together a strong core of experts on megacities, satellite observations, high-resolution modeling, and emission inventories. Our proposed work will provide often-overlooked quantitative information of anthropogenic CO2 emissions, which will be essential to achieve OCO-2’s primary science goals.

Publications:

Wu, D., Lin, J. C., Duarte, H. F., Yadav, V., Parazoo, N. C., Oda, T., Kort, E. A. A Model for Urban Biogenic CO<sub>2</sub> Fluxes: Solar-Induced Fluorescence for Modeling Urban biogenic Fluxes (SMUrF v1) DOI: 10.5194/gmd-2020-301

Wu, D., Lin, J. C., Oda, T., Kort, E. A. 2020. Space-based quantification of per capita CO2 emissions from cities. Environmental Research Letters. 15(3), 035004. DOI: 10.1088/1748-9326/ab68eb

Wu, D., Lin, J. C., Oda, T., Ye, X., Lauvaux, T., Yang, E. G., Kort, E. A. A Lagrangian Approach Towards Extracting Signals of Urban CO<sub>2</sub> Emissions from Satellite Observations of Atmospheric Column CO<sub>2</sub> (XCO<sub>2</sub>): X-Stochastic Time-Inverted Lagrangian Transport model ("X-STILT v1.1") DOI: 10.5194/gmd-2018-123