47 research outputs found

    Carbon Monitor Cities, near-real-time daily estimates of CO2 emissions from 1500 cities worldwide

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    Building on near-real-time and spatially explicit estimates of daily carbon dioxide (CO2) emissions, here we present and analyze a new city-level dataset of fossil fuel and cement emissions. Carbon Monitor Cities provides daily, city-level estimates of emissions from January 2019 through December 2021 for 1500 cities in 46 countries, and disaggregates five sectors: power generation, residential (buildings), industry, ground transportation, and aviation. The goal of this dataset is to improve the timeliness and temporal resolution of city-level emission inventories and includes estimates for both functional urban areas and city administrative areas that are consistent with global and regional totals. Comparisons with other datasets (i.e. CEADs, MEIC, Vulcan, and CDP) were performed, and we estimate the overall uncertainty to be 21.7%. Carbon Monitor Cities is a near-real-time, city-level emission dataset that includes cities around the world, including the first estimates for many cities in low-income countries

    Precision requirements for space-based XCO2 data

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    Author Posting. © American Geophysical Union, 2007. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 112 (2007): D10314, doi:10.1029/2006JD007659.Precision requirements are determined for space-based column-averaged CO2 dry air mole fraction (XCO2) data. These requirements result from an assessment of spatial and temporal gradients in XCO2, the relationship between XCO2 precision and surface CO2 flux uncertainties inferred from inversions of the XCO2 data, and the effects of XCO2 biases on the fidelity of CO2 flux inversions. Observational system simulation experiments and synthesis inversion modeling demonstrate that the Orbiting Carbon Observatory mission design and sampling strategy provide the means to achieve these XCO2 data precision requirements.This work was supported by the Orbiting Carbon Observatory (OCO) project through NASA’s Earth System Science Pathfinder (ESSP) program. SCO and JTR were supported by a NASA IDS grant (NAG5-9462) to JTR

    Ultrafast Coherent Spectroscopy

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    Ultrafast coherent spectroscopy

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    IMPORTANCE OF SPECTROSCOPY FOR SPACE-BASED REMOTE SENSING

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    Author Institution: Research Division, Office of Earth Science, Code YS, National Aeronautics and Space AdministrationSpace-based remote sensing provides a powerful tool to study atmospheric trace constituent and aerosol distributions. A wide variety of spectroscopic techniques are used in these atmospheric composition measurements and they span a wavelength range from the microwave to vacuum ultraviolet - probing the full range of rotational, vibrational, and electronic transitions which molecules in the atmosphere can undergo. Retrieval of reliable column densities and mixing ratio profiles for these atmospheric constituents depends on the availability of accurate laboratory spectra obtained under appropriate atmospheric conditions. As instrumentation for remote-sensing improves in order to meet new challenges, such as those presented by the need for global tropospheric monitoring from space, our knowledge of spectral line and band parameters must improve as well. This talk will review the types of space-based observations available for atmospheric chemistry studies with a focus on the stratosphere, although some attention will be given to the troposphere and the mesosphere. Various applications of spectroscopy will be presented in each case, along with identification of significant unmet needs in the area of laboratory measurements. Several examples of the use of space-based data in advancing our understanding of atmospheric chemistry will be shown. The talk will conclude with a description of forthcoming space measurements planned by the United States and other nations

    NASA's Upper Atmosphere Research Program (UARP) and Atmospheric Chemistry Modeling and Analysis Program (ACMAP): Research Summaries 1997-1999

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    Under the mandate contained in the FY 1976 NASA Authorization Act, the National Aeronautics and Space Administration (NASA) has developed and is implementing a comprehensive program of research, technology development, and monitoring of the Earth's upper atmosphere, with emphasis on the upper troposphere and stratosphere. This program aims at expanding our chemical and physical understanding to permit both the quantitative analysis of current perturbations as well as the assessment of possible future changes in this important region of our environment. It is carried out jointly by the Upper Atmosphere Research Program (UARP) and the Atmospheric Chemistry Modeling and Analysis Program (ACMAP), both managed within the Research Division in the Office of Earth Science at NASA. Significant contributions to this effort have also been provided by the Atmospheric Effects of Aviation Project (AEAP) of NASA's Office of Aero-Space Technology. The long-term objectives of the present program are to perform research to: understand the physics, chemistry, and transport processes of the upper troposphere and the stratosphere and their control on the distribution of atmospheric chemical species such as ozone; assess possible perturbations to the composition of the atmosphere caused by human activities and natural phenomena (with a specific emphasis on trace gas geographical distributions, sources, and sinks and the role of trace gases in defining the chemical composition of the upper atmosphere); understand the processes affecting the distributions of radiatively active species in the atmosphere, and the importance of chemical-radiative-dynamical feedbacks on the meteorology and climatology of the stratosphere and troposphere; and understand ozone production, loss, and recovery in an atmosphere with increasing abundances of greenhouse gases. The current report is composed of two parts. Part 1 summarizes the objectives, status, and accomplishments of the research tasks supported under NASA UARP and ACMAP in a document entitled, Research Summaries 1997- 1999. Part 2 is entitled Present State of Knowledge of the Upper Atmosphere 1999 An Assessment Report

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