Author/Authors :
lamsal, l. n. universities space research association - goddard earth sciences technology and research, Maryland, USA , lamsal, l. n. nasa goddard space flight center, Maryland, USA , lamsal, l. n. nasa goddard space flight center, Maryland, USA , janz, s. j. nasa goddard space flight center, Maryland, USA , krotkov, n. a. nasa goddard space flight center, Maryland, USA , pickering, k. e. nasa goddard space flight center, Maryland, USA , spurr, r. j. d. rt solutions, Massachusetts, USA , kowalewski, m. g. nasa goddard space flight center, Maryland, USA , kowalewski, m. g. nasa goddard space flight center, Maryland, USA , kowalewski, m. g. universities space research association - goddard earth sciences technology and research, Maryland, USA , loughner, c. p. university of maryland - earth system science interdisciplinary center, Maryland, USA , loughner, c. p. nasa goddard space flight center, Maryland, USA , crawford, j. h. nasa langley research center, Virginia, USA , swartz, w. h. johns hopkins university - applied physics laboratory, Maryland, USA , herman, j. r. university of maryland - joint center for earth systems technology, Maryland, USA , herman, j. r. nasa goddard space flight center, Maryland, USA
Abstract :
Nitrogen dioxide (NO_2) is a short-lived atmospheric pollutant that serves as an air quality indicator and is itself a health concern. The Airborne Compact Atmospheric Mapper (ACAM) was flown on board the NASA UC-12 aircraft during the Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality Maryland field campaign in July 2011. The instrument collected hyperspectral remote sensing measurements in the 304–910nm range, allowing daytime observations of several tropospheric pollutants, including nitrogen dioxide (NO_2), at an unprecedented spatial resolution of 1.5 × 1.1 km^2. Retrievals of slant column abundance are based on the differential optical absorption spectroscopy method. For the air mass factor computations needed to convert these retrievals to vertical column abundance, we include high-resolution information for the surface reflectivity by using bidirectional reflectance distribution function data from the Moderate Resolution Imaging Spectroradiometer. We use high-resolution simulated vertical distributions of NO_2 from the Community Multiscale Air Quality and Global Modeling Initiative models to account for the temporal variation in atmospheric NO_2 to retrieve middle and lower tropospheric NO_2 columns (NO_2 below the aircraft). We compare NO_2 derived from ACAM measurements with in situ observations from NASA’s P-3B research aircraft, total column observations from the ground-based Pandora spectrometers, and tropospheric column observations from the space-based Ozone Monitoring Instrument. The high-resolution ACAM measurements not only give new insights into our understanding of atmospheric composition and chemistry through observation of subsampling variability in typical satellite and model resolutions, but they also provide opportunities for testing algorithm improvements for forthcoming geostationary air quality missions.
