Primary and secondary sources of formaldehyde in urban atmospheres: Houston Texas region
Journal article, 2012
We evaluate the rates of secondary production and primary emission of formaldehyde (CH2O) from petrochemical industrial facilities and on-road vehicles in the Houston Texas region. This evaluation is based upon ambient measurements collected during field studies in 2000, 2006 and 2009. The predominant CH2O source (92 +/- 4% of total) is secondary production formed during the atmospheric oxidation of highly reactive volatile organic compounds (HRVOCs) emitted from the petrochemical facilities. Smaller contributions are primary emissions from these facilities (4 +/- 2%), and secondary production (similar to 3%) and primary emissions (similar to 1%) from vehicles. The primary emissions from both sectors are well quantified by current emission inventories. Since secondary production dominates, control efforts directed at primary CH2O emissions cannot address the large majority of CH2O sources in the Houston area, although there may still be a role for such efforts. Ongoing efforts to control alkene emissions from the petrochemical facilities, as well as volatile organic compound emissions from the motor vehicle fleet, will effectively reduce the CH2O concentrations in the Houston region. We do not address other emission sectors, such as off-road mobile sources or secondary formation from biogenic hydrocarbons. Previous analyses based on correlations between ambient concentrations of CH2O and various marker species have suggested much larger primary emissions of CH2O, but those results neglect confounding effects of dilution and loss processes, and do not demonstrate the causes of the observed correlations. Similar problems must be suspected in any source apportionment analysis of secondary species based upon correlations of ambient concentrations of pollutants.
statistical-analysis
ozone formation
stratosphere
carbonyls
airborne
nox
hydrocarbons
ambient air
emission inventories
air-quality
Author
D. D. Parrish
National Oceanic and Atmospheric Administration
T. B. Ryerson
National Oceanic and Atmospheric Administration
Johan Mellqvist
Chalmers, Earth and Space Sciences, Optical Remote Sensing
John Johansson
Chalmers, Earth and Space Sciences, Optical Remote Sensing
A. Fried
National Center for Atmospheric Research
D. Richter
National Center for Atmospheric Research
J. G. Walega
National Center for Atmospheric Research
R. A. Washenfelder
University of Colorado at Boulder
National Oceanic and Atmospheric Administration
J. A. De Gouw
University of Colorado at Boulder
National Oceanic and Atmospheric Administration
J. Peischl
University of Colorado at Boulder
National Oceanic and Atmospheric Administration
K. C. Aikin
University of Colorado at Boulder
National Oceanic and Atmospheric Administration
S. A. McKeen
University of Colorado at Boulder
National Oceanic and Atmospheric Administration
G. J. Frost
National Oceanic and Atmospheric Administration
University of Colorado at Boulder
F. C. Fehsenfeld
University of Colorado at Boulder
National Oceanic and Atmospheric Administration
S. C. Herndon
Aerodyne Research, Inc.
Atmospheric Chemistry and Physics
1680-7316 (ISSN) 1680-7324 (eISSN)
Vol. 12 7 3273-3288Subject Categories (SSIF 2011)
Meteorology and Atmospheric Sciences
DOI
10.5194/acp-12-3273-2012