Abstract Satellite observations of the total column dry‐air CO 2 (X CO2 ) are expected to support quantification and monitoring fossil fuel (ffCO emissions from urban areas. We evaluate utility Orbiting Carbon Observatory (OCO‐2) X retrievals optimize whole‐city emissions, using a Bayesian inversion system high‐resolution transport modeling. The uncertainties constrained related model, satellite measurements, local biospheric fluxes quantified. For first two uncertainty sources, we examine...

Abstract Urban areas are currently responsible for ∼70% of the global energy-related carbon dioxide (CO 2 ) emissions, and rapid ongoing urbanization is increasing number size cities. Thus, understanding city-scale CO emissions how they vary between cities with different urban densities a critical task. While relationship population density has been explored widely in prior studies, their conclusions were sensitive to inconsistent definitions boundaries reliance upon emission inventories...

Abstract. Urban regions are responsible for emitting significant amounts of fossil fuel carbon dioxide (FFCO2), and emissions at the finer, city scales more uncertain than those aggregated global scale. Carbon-observing satellites may provide independent top-down emission evaluations compensate sparseness surface CO2 observing networks in urban areas. Although some previous studies have attempted to derive signals from satellite column-averaged data (XCO2) using simple statistical measures,...

Urban areas, where more than 55% of the global population gathers, contribute 70% anthropogenic fossil fuel carbon dioxide (CO2ff) emissions. Accurate quantification CO2ff emissions from urban areas is great importance for formulating warming mitigation policies to achieve neutrality by 2050. Satellite-based inversion techniques are unique among "top-down" approaches, potentially allowing us track emission changes over cities globally. However, their accuracy still limited incomplete...

Abstract Improved observational understanding of urban CO 2 emissions, a large and dynamic global source fossil , can provide essential insights for both carbon cycle science mitigation decision making. Here we compare three distinct emissions inventory representations five Middle Eastern cities (Riyadh, Mecca, Tabuk, Jeddah, Baghdad) use independent satellite observations from the Orbiting Carbon Observatory‐2 (OCO‐2) to evaluate afternoon emissions. We column version Stochastic...

Abstract. When estimating fossil fuel carbon dioxide (FFCO2) emissions from observed CO2 concentrations, the accuracy can be hampered by biogenic exchanges during growing season, even for urban areas where strong are found. While fluxes have been studied extensively across natural vegetation types, within an area challenging to quantify due limited observations and differences between rural regions. Here we developed a simple model representation, i.e., Solar-Induced Fluorescence (SIF)...

Abstract Radiocarbon ( 14 C) is a powerful tracer of fossil emissions because fuels are entirely depleted in C, but observations CO 2 and especially CH 4 urban regions sparse. We present the first C both methane (CH ) carbon dioxide (CO an area (London) using recently developed sampling system. find that fraction atmospheric concentration consistently higher than simulated values dispersion model NAME coupled with emission inventories. Observed net biospheric uptake June–July not well...

Abstract. Bottom-up accounting methods of carbon dioxide (CO2) emissions can provide high-resolution estimates at a global scale; however, the necessary in situ observations to verify these are limited coverage. Space-based CO2 Earth’s atmosphere expand this coverage near-global scale inform cycle science and record emission trends. This work applied an observing system simulation experiment (OSSE) characterize flux information contained “Snapshot Area Map” (SAM) measurements from Orbiting...

Abstract. We assess the theoretical capability of upcoming France–UK MicroCarb satellite, which has a city-scan observing mode, to determine integrated urban emissions carbon dioxide (CO2). To achieve this we report results from series closed-loop numerical experiments that use an atmospheric transport model with anthropogenic and biogenic fluxes corresponding changes in CO2 column, accounting for measurement coverage due cloud loading. maximum posteriori inverse method infer based on...

Satellite data provides essential insights into the spatiotemporal distribution of CO2 concentrations. However, many atmospheric inverse models fail to adequately incorporate spatial and temporal correlations inherent in satellite observations often lack rigorous methods for estimating parameters like length scales. We introduce an inference model that processes covariance estimates hyperparameters such as Our approach uses Gaussian process (GP) machine learning (ML) modern probabilistic...

Cities with their large, dense populations are concentrated sources of CO2 emissions to the atmosphere. Although more than 60% global fossil fuel from cities, yet we lack high-quality city-level inventories and/or independent verification datasets across majority cities. Several cities have also adopted ambitious goals reaching net-zero by 2030 or 2050. In fact, most recently at COP28, several including those in non-Annex I countries, signed up be part Coalition for High Ambition Multilevel...

Abstract. Despite the need for researchers to understand terrestrial biospheric carbon fluxes account cycle feedbacks and predict future CO2 concentrations, knowledge of these at regional scale remains poor. This is particularly true in mountainous areas, where complex meteorology lack observations lead large uncertainties fluxes. Yet regions are often significant forest cover biomass found – i.e., areas that have potential serve as sinks. As carried out it imperative they properly...

Abstract. Carbon dioxide (CO2) and air pollutants such as carbon monoxide (CO) are co-emitted by many combustion sources. Previous efforts have combined satellite-based observations of multiple tracers to calculate their emission ratio (ER) for inferring efficiency at the regional city scale. Very few studies focused on sub-city scale or related it sectors using space-based observations. Several factors important interpreting deriving spatially resolved ERs from asynchronous satellite...

Tropical wetlands contribute ∼30% of the global methane (CH4) budget. Limited observational constraints on tropical wetland CH4 emissions lead to large uncertainties and disparities in representing emissions. In this work, we combine remote sensing observations with atmospheric models investigate dry season from Pantanal region South America. We incorporate inundation maps generated Cyclone Global Navigation Satellite System (CYGNSS) satellite constellation together traditional generate an...

High concentrations of ground-level ozone affect human health, plants, and animals. Reducing pollution in rural regions, where local emissions are already low, poses challenge. We use meteorological back-trajectories, air quality model sensitivity analysis, satellite remote sensing data to investigate the sources Yuma, Arizona find strong international influences from Northern Mexico on 12 out 16 exceedance days. that such exceedances could not be mitigated by reducing Arizona; complete...

Abstract Presented here is a new dust modeling framework that uses backward-Lagrangian particle dispersion model coupled with emission model, both driven by meteorological data from the Weather Research and Forecasting (WRF) Model. This was tested for spring of 2010 at multiple sites across northern Utah. Initial results March–April showed able to replicate 27–28 April event; however, it unable reproduce significant wind-blown event on 30 March 2010. During this event, significantly...

A growing constellation of satellites is providing near-global coverage column-averaged CO2 observations. Launched in 2019, NASA's OCO-3 instrument set to provide XCO2 observations at a high spatial and temporal resolution for regional domains (100 × 100 km). The atmospheric column version the Stochastic Time-Inverted Lagrangian Transport (X-STILT) model an established method determining influence upwind sources on measurements atmosphere, means analysis current future space-based...

The fluxes of carbon dioxide (CO2) to and from vegetation can be significant on a regional scale. It is therefore important understand the biogenic CO2 in order quantify local budgets. Greenbelt Ontario protected region cropland natural surrounding Greater Toronto Hamilton Area (GTHA) Ontario, Canada. Recently, changes were proposed Greenbelt, including removal 2,995 ha (7,400 acres) land replaced with housing. In this study, we estimate entire as well areas that for by using modified...

Abstract. Expanding urban populations and the significant contribution of cities to global fossil-fuel CO2 (CO2ff) emissions emphasize necessity achieving independent accurate quantifications from area. In this paper, we assess utility total column dry air mole fraction (XCO2) data retrieved NASA's Orbiting Carbon Observatory 2 (OCO-2) observations quantify CO2ff cities. Observing System Simulation Experiments (OSSEs) are implemented by forward modeling meteorological fields XCO2. The impact...

We present ab initio calculations of the temperature-dependent exchange energy between a classical charged point particle and phonons crystalline material. The phonons, which are computed using density functional perturbation theory (DFPT) methods, interact with moving via Coulomb interaction induced in material by phonon excitation charge particle. Energy relaxation rates time-dependent theory. method, is applicable wherever DFPT is, illustrated results for CsI, an important scintillator...

Abstract The COVID‐19 pandemic resulted in a widespread lockdown during the spring of 2020. Measurements collected on light rail system Salt Lake Valley (SLV), combined with observations from Utah Urban Carbon Dioxide Network observed notable decrease urban CO 2 concentrations 2020 relative to previous years. These decreases coincided ∼30% reduction average traffic volume. measurements across SLV were used within Bayesian inverse model spatially allocate anthropogenic emission reductions for...

Fluxes of carbon dioxide (CO) to and from vegetation can be significant on a regional scale. It is therefore important understand biogenic CO fluxes in order quantify local budgets. However, these are often difficult estimate urban emission studies. This work uses the Solar Induced Fluorescence (SIF) for Modelling Urban (SMUrF) model Vegetation Photosynthesis Respiration Model (UrbanVPRM) around Greater Toronto Hamilton Area, most populous region Canada. We have made several modifications...

Abstract Over the past decade, 1000s of cities have pledged reductions in carbon dioxide emissions. However, tracking progress toward these pledges has largely relied exclusively on activity-based, self-reported emissions inventories, which often underestimate due to incomplete accounting. Furthermore, lack a consistent framework that may be deployed broadly, across political boundaries, hampers understanding changes both city-scale and global summation urban mitigation actions, with insight...