Open AccessNO y lifetimes and O 3 production efficiencies in urban and power plant plumes: Analysis of field data
Author(s) -
Nunnermacker L. J.,
Kleinman L. I.,
Imre D.,
Daum P. H.,
Lee Y.N.,
Lee J. H.,
Springston S. R.,
Newman L.,
Gillani N.
Publication year - 2000
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/1999jd900753
Subject(s) - plume , environmental science , deposition (geology) , ozone , analytical chemistry (journal) , meteorology , atmospheric sciences , physics , chemistry , environmental chemistry , geology , geomorphology , sediment
In an effort to describe and characterize power plant plumes in the Nashville region, emissions from a small power plant (Gallatin) and a large power plant (Paradise) were examined using data obtained on the Department of Energy G‐1 airborne sampling platform. Observations made on July 3, 7, 15, 17, and 18, 1995, were compiled, and a kinetic analysis of the chemical evolution of the power plant plumes was performed. Analysis of the power plant plume data revealed a very active photochemistry, as had been determined previously for the urban plume. Ozone production efficiencies (OPE), defined as the number of molecules of O 3 formed per NO x molecule consumed, were found to be 3 for Gallatin and 2 for Paradise. Lifetimes for NO x (2.8 and 4.2 hours) and NO y (7.0 and 7.7 hours) were determined for Gallatin and Paradise, respectively. These NO x and NO y lifetimes imply rapid loss of NO z (NO z is assumed to be primarily HNO 3 ). Lifetimes for NO z are calculated to be 3 and 2.5 hours for Gallatin and Paradise, respectively. A sensitivity analysis indicates that the Gallatin NO z lifetime could be as long as 5 hours, bringing it into agreement with the value determined for the Nashville urban plume. It is unlikely that the Paradise NO z lifetime is as long as 4 hours. If NO z loss is attributed to dry deposition, a 3 hour lifetime implies a deposition velocity greater than 10 cm s −1 , which is much faster than expected based on accepted theory. Possible reasons for this discrepancy are discussed.