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Measurements of HONO, NO, NO y and SO 2 in aircraft exhaust plumes at cruise
Author(s) -
Jurkat T.,
Voigt C.,
Arnold F.,
Schlager H.,
Kleffmann J.,
Aufmhoff H.,
Schäuble D.,
Schaefer M.,
Schumann U.
Publication year - 2011
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 - 10.1029/2011gl046884
Subject(s) - nox , nitrous acid , nitrogen oxide , sulfur dioxide , sulfuric acid , aerosol , environmental science , sulfur , nitrogen , atmospheric chemistry , meteorology , atmospheric sciences , environmental chemistry , chemistry , inorganic chemistry , combustion , geology , ozone , organic chemistry , physics
Measurements of gaseous nitrogen and sulfur oxide emissions in young aircraft exhaust plumes give insight into chemical oxidation processes inside aircraft engines. Particularly, the OH‐induced formation of nitrous acid (HONO) from nitrogen oxide (NO) and sulfuric acid (H 2 SO 4 ) from sulfur dioxide (SO 2 ) inside the turbine which is highly uncertain, need detailed analysis to address the climate impact of aviation. We report on airborne in situ measurements at cruise altitudes of HONO, NO, NO y , and SO 2 in 9 wakes of 8 different types of modern jet airliners, including for the first time also an A380. Measurements of HONO and SO 2 were made with an ITCIMS (Ion Trap Chemical Ionization Mass Spectrometer) using a new ion‐reaction scheme involving SF 5 − reagent ions. The measured molar ratios HONO/NO and HONO/NO y with averages of 0.038 ± 0.010 and 0.027 ± 0.005 were found to decrease systematically with increasing NO x emission‐index (EI NO x ). We calculate an average EI HONO of 0.31 ± 0.12 g NO 2 kg −1 . Using reliable measurements of HONO and NO y , which are less adhesive than H 2 SO 4 to the inlet walls, we derive the OH‐induced conversion fraction of fuel sulfur to sulfuric acid ɛ with an average of 2.2 ± 0.5 %. ɛ also tends to decrease with increasing EI NO x , consistent with earlier model simulations. The lowest HONO/NO, HONO/NO y and ɛ was observed for the largest passenger aircraft A380.