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Measurement of NO and NO y emission indices during SUCCESS
Author(s) -
Campos T. L.,
Weinheimer A. J.,
Zheng J.,
Montzka D. D.,
Walega J. G.,
Grahek F. E.,
Vay S. A.,
Collins J. E.,
Wade L. O.,
Sachse G. W.,
Anderson B. E.,
Brune W. H.,
Tan D.,
Faloona I.,
Baughcum S. L.,
Ridley B. A.
Publication year - 1998
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/97gl03480
Subject(s) - environmental science , altitude (triangle) , mach number , atmospheric sciences , meteorology , vortex , physics , mechanics , mathematics , geometry
Exhaust measurements in the wake vortex regime of the NASA Boeing 757 aircraft were made during the SUbsonic aircraft: Contrails and Cloud Effects Special Study. Emission indices for NO and NO y were calculated from in situ measurements taken on board the NASA DC‐8 for plumes aged 20–300 seconds. The average NO emission index is 7.5 g NO 2 /kg fuel for mean conditions of 37 kft altitude, 0.7 Mach and 0.34 kg/s fuel flow rate. Comparison is made between measured indices and predictions based on ground engine test data and a fuel flow model. Measurements are positively correlated but are on average 22% higher than predictions, with considerable scatter and systematic deviations in measurements made under low thrust conditions. These conditions are lower than typical in commercial cruise operation of the 757, for which the model was optimized. No statistically significant change in nitrogenous emissions is observed for an order of magnitude change in fuel sulfur content. Estimation of the NO 2 from photochemical calculations implies a contribution to NO x of 5–19%. Examination of exhaust composition shows that 95% of the NO y is in the form of NO x .