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Spatial and temporal variability of ground and satellite column measurements of NO 2 and O 3 over the Atlantic Ocean during the Deposition of Atmospheric Nitrogen to Coastal Ecosystems Experiment
Author(s) -
Martins Douglas K.,
Najjar Raymond G.,
Tzortziou Maria,
Abuhassan Nader,
Thompson Anne M.,
Kollonige Debra E.
Publication year - 2016
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1002/2016jd024998
Subject(s) - environmental science , water column , satellite , atmospheric sciences , deposition (geology) , mixing ratio , troposphere , boundary layer , planetary boundary layer , column (typography) , oceanography , geology , structural basin , paleontology , physics , aerospace engineering , engineering , thermodynamics , structural engineering , connection (principal bundle)
In situ measurements of O 3 and nitrogen oxides (NO + NO 2 ≡ NO x ) and remote sensing measurements of total column NO 2 and O 3 were collected on a ship in the North Atlantic Ocean as part of the Deposition of Atmospheric Nitrogen to Coastal Ecosystems (DANCE) campaign in July–August 2014, ~100 km east of the mid‐Atlantic United States. Relatively clean conditions for both surface in situ mixing ratio and total column O 3 and NO 2 measurements were observed throughout the campaign. Increased surface and column NO 2 and O 3 amounts were observed when a terrestrial air mass was advected over the study region. Relative to ship‐based total column measurements using a Pandora over the entire study, satellite measurements overestimated total column NO 2 under these relatively clean atmospheric conditions over offshore waters by an average of 16%. Differences are most likely due to proximity, or lack thereof, to surface emissions; spatial averaging due to the field of view of the satellite instrument; and the lack of sensitivity of satellite measurements to the surface concentrations of pollutants. Total column O 3 measurements from the shipboard Pandora showed good correlation with the satellite measurements ( r = 0.96), but satellite measurements were 3% systematically higher than the ship measurements, in agreement with previous studies. Derived values of boundary layer height using the surface in situ and total column measurements of NO 2 are much lower than modeled and satellite‐retrieved boundary layer heights, which highlight the differences in the vertical distribution between terrestrial and marine environments.