Evaluation of U.S. NOx emissions with satellite-based observations and model simulations

November 05, 2009

Greg Frost (NOAA)

Hosted by Colette Heald

Abstract

Nitrogen oxides (NOx = NO + NO2) of anthropogenic origin are produced primarily from fossil fuel combustion by motor vehicles, electrical power generation, and industrial processes. Accurate accounting of NOx emissions is crucial for the prediction of the atmospheric formation of ozone and particulate matter. Each of these pollutants is subject to air quality standards in most of the industrialized world. Chemical-transport model calculations, which inform the design of pollution control strategies and test our scientific understanding of the troposphere, require detailed "bottom-up" emissions inventories. For most sources, bottom-up inventories are derived from complex calculations of source activity and emission factors. Independent evaluation is necessary to establish confidence in these inventories' predicted emission magnitudes and trends.

Space-based NO2 observations have been widely used to monitor the sources of NOx and improve bottom-up emission inventories at a global scale since the data from the GOME instrument became available in 1997. Finer scale measurements by the SCIAMACHY and OMI instruments on newer polar-orbiting satellites provide the capability of examining NOx sources at regional to local scales. Over the past several years, our group has analyzed vertical columns of NO2 retrieved by each of these satellite instruments and compared them to columns calculated by a regional air quality model. I will present some examples of the application of this approach to evaluate bottom-up NOx inventories and infer trends in NOx emissions from a variety of U.S. sources, including power generation and urban areas.

Authors and Affiliations:

Gregory Frost (1,2), Si-Wan Kim (1,2), Stuart McKeen (1,2), Eirh Yu Hsie (1,2),
Michael Trainer (1), Andreas Heckel (3,4), Andreas Richter (3), James Gleason (5), John
Burrows (3,6), Claire Granier (1,2,7,8)

(1) Chemical Sciences Division, Earth System Research Laboratory, NOAA, Boulder, Colorado, USA.
(2) Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, USA.
(3) Institute of Environmental Physics and Institute of Remote Sensing, University of Bremen, Bremen, Germany.
(4) Department of Geography, Swansea University, Swansea, UK.
(5) Laboratory for Atmospheres, NASA Goddard Space Flight Center, Greenbelt, Maryland, USA.
(6) Center for Ecology and Hydrology, Wallingford, UK.
(7) UniversitÃ© Pierre et Marie Curie, UMR7620, Paris, France.
(8) Service dâ€™AÃ©ronomie, UMR7620, CNRS, Paris, France.