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  • Simulated CO2 tracer concentrations in the Northern Hemisphere from a tagged transport model GEOS-Chem v12.0.0

    work
    Creator:
    Lin, Xin, Keppel-Aleks, Gretchen, Rogers, Brendan M., and Birch, Leah
    Description:
    The data contain the daily-averaged atmospheric concentrations of CO2 tracers in the Northern Hemisphere simulated from a tagged tracer transport model GEOS-Chem v12.0.0. Thirteen land flux regions are defined and tagged in the model to separate their imprints on the long-term atmospheric CO2 seasonal amplification in Northern Hemisphere. A file describing the delineation of these land flux regions is also provided. See the README file for more details on the dataset and model configurations.
    Keyword:
    carbon dioxide, seasonal cycle, amplification, Arctic-boreal, global change, and GEOS-Chem
    Citation to related publication:
    Lin, X., Rogers, B. M., Sweeney, C., Chevallier, F., Arshinov, M., Dlugokencky, E., Machida, T., Sasakawa, M., Tans, P., & Keppel-Aleks, G. (2020). Siberian and temperate ecosystems shape Northern Hemisphere atmospheric CO2 seasonal amplification. Proceedings of the National Academy of Sciences, 117(35), 21079–21087.
    Discipline:
    Science

  • Data in support of the study "Using space-based observations and Lagrangian modeling to evaluate urban carbon dioxide emissions in the Middle East"

    work
    Creator:
    Yang, Emily G, Kort, Eric A, Wu, Dien, Lin, John C, Oda, Tomohiro, Ye, Xinxin, and Lauvaux, Thomas
    Description:
    This data set supports a study that seeks to evaluate global fossil fuel CO2 emissions inventory representations of CO2 emissions of five cities in the Middle East, and assess the ability of satellite observations to inform this evaluation. Improved observational understanding of urban CO2 emissions, a large and dynamic global source of fossil CO2, can provide essential insights for both carbon cycle science and mitigation decision making. In this study we compare three distinct global CO2 emissions inventory representations of urban CO2 emissions for five Middle Eastern cities (Riyadh, Mecca, Tabuk, Jeddah, and Baghdad) and use independent satellite observations from the Orbiting Carbon Observatory-2 (OCO-2) satellite to evaluate the inventory representations of afternoon emissions. We use the column version of the Stochastic Time-Inverted Lagrangian Transport (X-STILT) model to account for atmospheric transport and link emissions to observations. We compare XCO2 simulations with observations to determine optimum inventory scaling factors. Applying these factors, we find that the average summed emissions for all five cities are 100 MtC/y (50-151, 90% CI), which is 2.0 (1.0, 3.0) times the average prior inventory magnitudes. The total adjustment of the emissions of these cities comes out to ~7% (0%, 14%) of total Middle Eastern emissions (~700 MtC/y). We find our results to be insensitive to the prior spatial distributions in inventories of the cities’ emissions, facilitating robust quantitative assessments of urban emission magnitudes without accurate high-resolution gridded inventories. and There are three files included in this data set, and all data are in tab-delimited form. The first file, xco2_lat.zip, contains 26 separate text files, each named by the city and date of the corresponding OCO-2 overpass. Each of these 26 files includes overpass-specific data, with modeled and observed XCO2 values binned by 0.1 degree of latitude. The file overpass_scaling_factors.txt provides the scaling factors for each overpass used in this study. The file city_estimates.txt provides the scaled emissions estimates for each city (or sum of cities) as well as the lower and upper bounds of the 90% confidence intervals, for each inventory.
    Keyword:
    greenhouse gases, carbon dioxide, urban, cities, satellite, remote sensing, Lagrangian modeling, emissions inventories, carbon cycle, and climate
    Citation to related publication:
    Yang, E. G., Kort, E. A., Wu, D., Lin, J. C., Oda, T., Ye, X., & Lauvaux, T. (2020). Using space‐based observations and Lagrangian modeling to evaluate urban carbon dioxide emissions in the Middle East. Journal of Geophysical Research: Atmospheres, 125, e2019JD031922.  https://doi.org/10.1029/2019JD031922
    Discipline:
    Science

  • Simulated CO2 dataset using the atmospheric transport model GEOSChem v12.0.0: Response to regional land carbon fluxes

    work
    Creator:
    Basile, Samantha, Lin, Xin, and Keppel-Aleks, Gretchen
    Description:
    Files contain the atmospheric CO2 mole fraction responses to land flux type (HRcasa, HRcorpse, HRmimics) and land flux region (latband variable). Land flux regions are categorized as: Northern Hemisphere high latitudes (NHL; 61 to 90°N), midlatitudes (NML; 24 to 60°N), tropics (NT; 1 to 23°N), Southern Hemisphere tropics (ST; 0 to 23°S), and extratropics (SE; 24 to 90°S). See the README file for how these land flux region definitions relate to the file's latband variable. and To cite dataset: Basile, S., Lin, X., Keppel-Aleks, G. (2019). Simulated CO2 dataset using the atmospheric transport model GEOSChem v12.0.0: Response to regional land carbon fluxes [Data set]. University of Michigan - Deep Blue.  https://doi.org/10.7302/xjzc-xy05
    Keyword:
    carbon dioxide, soil heterotrophic respiration, GEOSChem, HR, CO2, CASA-CNP, CORPSE, and MIMICS
    Discipline:
    Science